主题介绍
LS-DYNA 的多物理场耦合在锂电池机械滥用上的仿真介绍,可以用在电动车或混动车的电池机械安全上,包括锂电池挤压、热管理、针刺等多物理场工况上。介绍Randles等效电路模型、实体单元模型、厚壳单元模型、batmac模型、meshless模型及相关案例。
如有任何问题请点击以下链接进入答疑室与我们的技术专家进行交流互动
https://v.ansys.com.cn/live/499e779b
演讲人简介
Pierre L'Eplattenier Ansys LST Principle R&D Engineer
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我是Pierre L'Eplattenier 我在LST工作
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今天 我将和大家谈谈
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基于LS-DYNA
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实现电动或混合动力汽车
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碰撞仿真蓄电池集成
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的方法
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同时 我要感谢我的同事
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Inaki Caldichoury
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他和我一起研究了这个话题
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并帮助我准备了这次演讲
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这次演讲主要涉及
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汽车安全方面的一些内容
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1966年
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美国颁布了
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国家交通及机动车
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安全法
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为机动车和道路交通安全
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制定了新的标准
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正如您所看到的
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右边的曲线
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从那时起
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汽车碰撞死亡的人数
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减少了很多
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这在很大程度上要归功于安全带
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安全气囊
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以及从汽车碰撞测试中得出
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的一般知识
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在过去几十年里
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仿真技术的
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使用
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已经极大地
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帮助了人们更好地理解
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汽车碰撞事件
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以及各种
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可用的商业解决方案
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LS-DYNA
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已经
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被汽车行业
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广泛接受
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最近出现了
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一种新型的机车
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它实际上
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最早出现在
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20世纪初
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近年来
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我们看到了电动汽车
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和续航里程的增加
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这将导致汽车用户
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越来越难以在
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刚性容器中
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保护蓄电池
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因此仿真可能会对蓄电池的
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安全性
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有很大帮助
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嗯
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但因此这些蓄电池也带来了新的
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挑战
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正如大家在新闻上看到的
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蓄电池
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和电动汽车混合动力汽车
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经常会发生碰撞
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大家可以看到火势相当严重
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那么对于蓄电池在
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汽车碰撞之后不发生火灾
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我们有多大的信心呢
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作为消费者 我们有多安全
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作为工程师 我们能预见这些问题吗
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您的理解程度如何
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我们应当在多大程度上保护蓄电池
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而这正是仿真
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可以发挥很大作用
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的地方
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现在仿真蓄电池崩溃是相当有
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挑战性的
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首先
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物理学是非常复杂的
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它是一个将机械电磁学
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电化学和热紧密结合
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在一起的多重物理
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蓄电池的
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长度范围很广 尺寸大约在
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1米
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左右
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而电池中各个层的
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厚度约为
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几十微米
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正是该层面上
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内部
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短路发生并触发大的热逃逸
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蓄电池
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着火
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此外 其时间范围也很广
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从毫秒级的崩溃
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发生在毫秒内
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到热逃逸 火灾和爆炸
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可能需要几分钟到
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几小时甚至几天的时间
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幸运的是 现在有了LS-DYNA
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我们已经将力学 电
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和热紧密结合起来
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而我们必须解决的就是
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右下方图示的
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电化学
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那么 现在我们有一个将
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机械部件耦合在一起的模块
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其可以将位移提供给
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电气部件
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并由电化学部件进行考虑
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然后
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我们将回到这个问题上来
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在这部分 我们使用等效电路
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因此我们
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可以通过机械变形
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触发
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内部短路
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电气和电化学与
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热
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耦合
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因此我们将焦耳加热归为热
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然后
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我们得到温度参数
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并且
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嗯
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热和机械
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也与
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力学耦合在一起 最近
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我们将ICFD模块添加到
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整个链中 其中热和
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ICFD
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通过共轭传热求解器进行通信
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并且
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CFD和电气设备可以
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直接通信 这样
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我们就可以得到一种导电流体
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稍后我们将对此
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进行简单的介绍
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现在
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根据用户想要研究的比例
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或细节
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我们有四个模型
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正如我所说的 内部短路发生在
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电池级别 这也是
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内部失控的
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根本原因
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因此 了解机械或热滥用对
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单个电池
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的影响非常重要
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这可能取决于电池
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的类型
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为此 我们创建了我们称之为固体
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单元的模型 其中所有的层
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都是用
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固体单元制成的
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与力学 热及
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电磁学中使用的网格一样
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我们还创建了复合Tshell模型
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其中
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机械部分使用复合
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Tshell建模
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电磁学和热仍然使用我们在
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后台展示的底层实体网格
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它允许使用较少的单元
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和实体单元模型加快
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运行速度
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这两种模型都用于
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在
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模块单元级别进行典型研究
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也许不是很大的模型
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因此 从计算方面上讲 在
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每个
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电池层的级别上对完整电池进行建模
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的成本非常高
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所以我们创建了名为
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batmac的宏模型
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该模型允许使用
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从单个电池
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研究中获得的信息
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特别是完整电池模型
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在汽车碰撞中发生内部短路
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的信息
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这就是宏模型
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这个模型也可以用于内部和外部
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短路
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但现在可用于电池组或蓄电池
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对于此模型 我们将一个或几个
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沿厚度方向的固体单元用于
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力学 电磁学和热
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从而在正负集电器处各
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形成
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两个场
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此外我们还创建了无网格模型
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在该模型中 我们不关心
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电池内部
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发生了什么
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但是我们仍然拥有所有等效
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电路以及
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电池可以输出的
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能量等
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该模型主要是用于外部短路
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00:06:50.32 - 00:06:54.14 11
所有这些模型都基于等效
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电路
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00:06:54.74 - 00:06:58.52 12
所以我们使用分布随机模型
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而在该模型中 我们没有仿真
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阳极、阴极和分离器之间发生的
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电化学反应
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00:07:06.42 - 00:07:10.22 5
而是使用了
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电池模型中常用的
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等效电路
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00:07:12.67 - 00:07:15.93 16
但我们在分布式模式下使用这些模型
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00:07:15.93 - 00:07:19.72 10
这意味着每个节点都有
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一个等效电路
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00:07:20.82 - 00:07:23.42 3
在正负
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集电器中
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正集电器的每个节点
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都连接到
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负集电器上对应的
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00:07:29.55 - 00:07:30.12 3
节点上
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00:07:30.12 - 00:07:32.67 10
如Randles电路
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00:07:32.67 - 00:07:35.61 13
因此这种分布电路模型的优点
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00:07:35.61 - 00:07:36.53 1
是
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计算成本不太高
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00:07:39.40 - 00:07:42.37 11
它们能准确地再现电池的
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主要特征
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电气和热特性
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它们可以轻松获得
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通过电压和电流测量得到的
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电池参数
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将模型与
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外部电路
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进行电气连接 例如连接器总线
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00:07:58.24 - 00:07:59.02 14
并对外部短路进行建模非常简单
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最主要的是能够对
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内部
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短路进行建模
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00:08:02.92 - 00:08:05.67 9
如右下角所示 如果
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集电器发生变形 则
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00:08:08.62 - 00:08:09.71 13
可以用内部短路电阻代替部分
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Randles
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电路
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00:08:13.21 - 00:08:13.57 4
并且可以
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根据局部机械参数
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或运行变形
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来确定
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短路电阻值
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00:08:24.22 - 00:08:27.11 11
为了处理不同的时间尺度
-
00:08:27.11 - 00:08:27.43 4
我们通常
-
00:08:27.43 - 00:08:30.29 12
是在毫秒左右的碰撞时间里
-
00:08:30.29 - 00:08:30.93 2
利用
-
00:08:30.99 - 00:08:33.85 6
碰撞时间步长
-
00:08:33.85 - 00:08:34.55 10
研究力学 电磁学和热
-
00:08:34.61 - 00:08:37.47 9
我们得到短路的变形
-
00:08:37.47 - 00:08:37.66 4
然后我们
-
00:08:37.66 - 00:08:40.52 12
通过冻结力学装置继续运行
-
00:08:40.52 - 00:08:40.96 4
我们只做
-
00:08:41.03 - 00:08:43.89 15
电磁学和热研究 现在的时间步长
-
00:08:43.89 - 00:08:44.27 2
更大
-
00:08:44.33 - 00:08:47.19 11
大约在秒左右 让蓄电池
-
00:08:47.19 - 00:08:47.63 6
通过短路放电
-
00:08:47.63 - 00:08:50.57 6
并使温度升高
-
00:08:50.57 - 00:08:51.42 4
如果需要
-
00:08:51.48 - 00:08:54.16 6
让蓄电池运行
-
00:08:54.16 - 00:08:56.71 12
几分钟或几小时 对于仿真
-
00:08:56.71 - 00:08:59.30 11
除了正确离散蓄电池放电
-
00:08:59.30 - 00:08:59.36 7
和温度升高之外
-
00:08:59.41 - 00:09:02.00 11
还得出了电磁和热求解器
-
00:09:02.00 - 00:09:02.98 5
对时间步长
-
00:09:03.04 - 00:09:05.51 4
不太敏感
-
00:09:05.51 - 00:09:09.04 9
因此可以将毫秒切换
-
00:09:09.04 - 00:09:09.28 1
至
-
00:09:09.36 - 00:09:11.48 4
秒时间段
-
00:09:11.48 - 00:09:14.39 14
现在 我将为大家展示一些案例
-
00:09:14.39 - 00:09:18.63 7
这是由福特公司
-
00:09:18.63 - 00:09:19.57 11
执行的一个外部短路案例
-
00:09:19.66 - 00:09:22.49 2
他们
-
00:09:22.49 - 00:09:22.71 5
用一些总线
-
00:09:22.71 - 00:09:26.00 11
把一个由五个电池组成的
-
00:09:26.00 - 00:09:26.15 8
小模块连接在一起
-
00:09:26.22 - 00:09:29.51 11
然后用它们来连接总线的
-
00:09:29.51 - 00:09:29.95 3
正极和
-
00:09:30.03 - 00:09:33.25 9
负极 再让电流流入
-
00:09:33.25 - 00:09:36.54 10
外部短路 他们观察到
-
00:09:36.54 - 00:09:37.85 6
总线和电池内
-
00:09:37.93 - 00:09:41.22 5
不同位置的
-
00:09:41.22 - 00:09:41.66 4
温度升高
-
00:09:41.73 - 00:09:45.02 10
并将其与实验结果进行
-
00:09:45.02 - 00:09:46.04 2
比较
-
00:09:46.04 - 00:09:50.52 10
大家从右图中可以看出
-
00:09:50.52 - 00:09:51.82 6
这两种结果的
-
00:09:51.92 - 00:09:52.72 5
匹配度很高
-
00:09:52.72 - 00:09:56.45 12
这是另一个外部短路的例子
-
00:09:56.45 - 00:09:56.87 2
它是
-
00:09:56.87 - 00:10:00.63 10
一个20个电池的模块
-
00:10:00.63 - 00:10:00.71 5
已经连接到
-
00:10:00.79 - 00:10:04.39 13
一些总线上 然后放置一块板
-
00:10:04.47 - 00:10:06.98 13
使所有这些总线一起受到撞击
-
00:10:06.98 - 00:10:10.38 7
变形并相互接触
-
00:10:10.38 - 00:10:13.40 9
因此 现在电流不再
-
00:10:13.40 - 00:10:13.73 2
流经
-
00:10:13.80 - 00:10:14.74 2
电池
-
00:10:14.74 - 00:10:18.16 8
但是可以通过短路
-
00:10:18.16 - 00:10:19.46 6
在这些不同的
-
00:10:19.53 - 00:10:22.96 8
总线之间相互接触
-
00:10:22.96 - 00:10:23.49 7
然后他们观察到
-
00:10:23.57 - 00:10:26.99 5
外部短路的
-
00:10:26.99 - 00:10:27.68 6
温度升高情况
-
00:10:27.68 - 00:10:30.67 14
这些操作是用无网格模型完成的
-
00:10:30.67 - 00:10:33.20 16
所以 这里还列举了一些其他的例子
-
00:10:33.20 - 00:10:36.67 10
左边的图示为外部短路
-
00:10:36.67 - 00:10:37.82 7
其中导电圆柱管
-
00:10:37.90 - 00:10:41.37 13
到达圆柱管所在的位置 并使
-
00:10:41.37 - 00:10:42.37 4
两个凸耳
-
00:10:42.45 - 00:10:45.92 13
接触 从而造成一些外部短路
-
00:10:45.92 - 00:10:47.46 5
和温度升高
-
00:10:47.46 - 00:10:49.92 6
在中间的图中
-
00:10:49.92 - 00:10:52.13 4
球体落在
-
00:10:52.13 - 00:10:55.30 9
10个电池的模块上
-
00:10:55.39 - 00:10:59.36 6
造成内部短路
-
00:10:59.36 - 00:10:59.81 9
它使用的是特征模型
-
00:10:59.81 - 00:11:03.38 6
右图所示的是
-
00:11:03.38 - 00:11:03.54 4
内部短路
-
00:11:03.62 - 00:11:06.87 12
使用的是batmac模型
-
00:11:06.95 - 00:11:10.52 14
其中我们有一个包含50块电池
-
00:11:10.52 - 00:11:10.60 5
的大电池组
-
00:11:10.60 - 00:11:14.85 16
这些电池组受到其中一个拐点的影响
-
00:11:14.85 - 00:11:16.45 14
从而产生了一些内部短路和温度
-
00:11:16.54 - 00:11:17.49 2
升高
-
00:11:17.49 - 00:11:21.71 11
这些示例都是可以操作的
-
00:11:21.71 - 00:11:28.20 16
现在看一下我们做了一些最新的研究
-
00:11:28.20 - 00:11:30.86 2
如果
-
00:11:30.86 - 00:11:31.09 1
呃
-
00:11:31.09 - 00:11:32.11 5
大家看一下
-
00:11:32.11 - 00:11:34.71 4
这是针刺
-
00:11:37.98 - 00:11:39.95 2
我们
-
00:11:41.99 - 00:11:44.45 5
仿真了穿刺
-
00:11:44.45 - 00:11:48.25 11
这个示例演示了钉子穿透
-
00:11:48.35 - 00:11:51.54 10
30个电池组并形成孔
-
00:11:51.54 - 00:11:54.23 7
在这个孔的周围
-
00:11:54.23 - 00:11:57.24 15
产生了一些短路 因此我们观察到
-
00:11:57.24 - 00:11:57.97 7
这些短路和温度
-
00:11:58.04 - 00:11:58.71 2
升高
-
00:11:58.71 - 00:12:01.36 20
我们使用batmac模型作为前10块电池
-
00:12:01.42 - 00:12:04.40 11
因为钉子在其穿透过程中
-
00:12:04.40 - 00:12:05.13 3
停止在
-
00:12:05.20 - 00:12:08.18 17
第10块电池 然后对其余的电池使用
-
00:12:09.37 - 00:12:12.06 9
这样我们就可以得出
-
00:12:12.13 - 00:12:12.60 9
来自所有其他电池的
-
00:12:12.60 - 00:12:15.61 2
能量
-
00:12:15.61 - 00:12:15.94 3
电流和
-
00:12:16.01 - 00:12:16.81 2
电压
-
00:12:16.81 - 00:12:19.82 7
但我们并不关心
-
00:12:19.82 - 00:12:20.22 3
电池的
-
00:12:20.29 - 00:12:21.09 4
内部情况
-
00:12:21.09 - 00:12:23.93 7
所以它是可用的
-
00:12:23.93 - 00:12:24.13 1
呃
-
00:12:24.13 - 00:12:27.14 15
此外 我们还做了一些关于热管理
-
00:12:27.14 - 00:12:27.67 4
的新研究
-
00:12:27.74 - 00:12:30.49 9
在batmac模型
-
00:12:30.49 - 00:12:32.54 16
热模型和CFD模型之间进行了耦合
-
00:12:32.54 - 00:12:34.60 4
这是一个
-
00:12:36.90 - 00:12:40.51 16
包含96个圆柱形电池的电池组示例
-
00:12:40.51 - 00:12:40.75 5
大家可以在
-
00:12:40.83 - 00:12:44.37 6
左上图中看到
-
00:12:44.45 - 00:12:48.06 11
冷却电池组有不同的方式
-
00:12:48.06 - 00:12:48.78 8
因为在正常使用时
-
00:12:48.78 - 00:12:50.86 6
电池组会发热
-
00:12:50.86 - 00:12:54.47 7
因此有直接气流
-
00:12:54.47 - 00:12:54.79 4
空气冷却
-
00:12:54.87 - 00:12:58.49 8
直接通过这些电池
-
00:12:58.49 - 00:12:59.61 3
然后有
-
00:12:59.69 - 00:13:03.31 11
底板进行间接的液体冷却
-
00:13:03.31 - 00:13:06.96 6
在底部模板上
-
00:13:06.96 - 00:13:07.13 11
大家可以看到有一个小管
-
00:13:07.13 - 00:13:10.84 9
一些水可以流经这个
-
00:13:10.84 - 00:13:11.33 2
小管
-
00:13:11.42 - 00:13:15.13 15
然后整个电池组可以通过底部管道
-
00:13:15.13 - 00:13:15.30 4
进行冷却
-
00:13:15.30 - 00:13:19.20 11
我们对此进行了一些仿真
-
00:13:19.20 - 00:13:19.37 8
大家可以看这里的
-
00:13:19.46 - 00:13:21.28 2
示例
-
00:13:21.28 - 00:13:25.15 11
是关于底板不冷却和液体
-
00:13:25.15 - 00:13:26.35 5
冷却的区别
-
00:13:26.44 - 00:13:30.31 6
大家可以看到
-
00:13:30.31 - 00:13:30.83 7
背面温度的重复
-
00:13:30.91 - 00:13:34.78 4
而且我们
-
00:13:34.78 - 00:13:34.95 7
获得了更多情况
-
00:13:34.95 - 00:13:38.84 6
因为没有冷却
-
00:13:38.84 - 00:13:39.10 5
我们观察到
-
00:13:39.19 - 00:13:43.07 12
模块温度增加到43摄氏度
-
00:13:43.07 - 00:13:45.85 10
而有液体冷却的情况下
-
00:13:45.85 - 00:13:48.54 10
温度增加到24摄氏度
-
00:13:48.54 - 00:13:50.67 1
嗯
-
00:13:50.67 - 00:13:52.48 8
现在是同一种情况
-
00:13:52.48 - 00:13:55.53 13
区别是左边显示的是空气冷却
-
00:13:55.60 - 00:13:57.84 10
右边是空气加液体冷却
-
00:13:57.84 - 00:14:00.83 11
这样大家可以重复地看到
-
00:14:00.90 - 00:14:03.95 11
使用不同类型的冷却系统
-
00:14:03.95 - 00:14:04.02 5
得到的情况
-
00:14:04.02 - 00:14:07.39 12
因此 在LS-DYNA中
-
00:14:07.39 - 00:14:07.99 8
也可以使用热管理
-
00:14:08.07 - 00:14:09.50 2
进行
-
00:14:09.50 - 00:14:13.58 16
电磁 热和ICFD之间的这种耦合
-
00:14:13.58 - 00:14:15.71 1
嗯
-
00:14:15.71 - 00:14:18.68 11
还有一个好处就是您可以
-
00:14:18.75 - 00:14:20.07 7
使用相同的网格
-
00:14:20.07 - 00:14:23.17 14
当然 您不用同时开展电池冷却
-
00:14:23.17 - 00:14:23.99 2
仿真
-
00:14:24.06 - 00:14:26.54 5
和碰撞实验
-
00:14:26.54 - 00:14:30.14 13
但是您可以把相同的网格模型
-
00:14:30.22 - 00:14:33.75 12
在稍后的碰撞中用于热管理
-
00:14:33.75 - 00:14:34.41 1
呃
-
00:14:37.45 - 00:14:41.87 7
然后我想展示的
-
00:14:41.87 - 00:14:42.26 5
另一个例子
-
00:14:42.36 - 00:14:42.95 4
大家请看
-
00:14:42.95 - 00:14:47.17 9
那么现在我们也能够
-
00:14:47.27 - 00:14:49.32 5
在ICFD
-
00:14:49.32 - 00:14:51.77 13
电磁和电池模块之间建立耦合
-
00:14:51.77 - 00:14:55.19 8
我们可以让导电水
-
00:14:55.29 - 00:14:57.05 4
流过电池
-
00:14:57.05 - 00:15:01.41 3
导电水
-
00:15:01.41 - 00:15:02.97 4
流过连接
-
00:15:03.06 - 00:15:07.43 12
电池的总线 并产生了一些
-
00:15:07.43 - 00:15:08.50 2
短路
-
00:15:08.50 - 00:15:11.83 13
因为现在电流可以通过导电水
-
00:15:11.83 - 00:15:12.05 8
从一个电池片流到
-
00:15:12.12 - 00:15:15.46 6
下一个电池片
-
00:15:15.61 - 00:15:18.66 5
并完全改变
-
00:15:18.66 - 00:15:19.61 3
电流和
-
00:15:19.67 - 00:15:22.73 14
温度的重复性 因此大家可以从
-
00:15:22.73 - 00:15:23.00 8
右边的图示中看到
-
00:15:23.06 - 00:15:26.12 7
在这样的情况下
-
00:15:26.12 - 00:15:26.79 7
电荷状态会大大
-
00:15:26.79 - 00:15:27.57 2
减弱
-
00:15:27.57 - 00:15:27.86 1
嗯
-
00:15:27.86 - 00:15:30.61 7
当您把水连接到
-
00:15:30.69 - 00:15:33.87 7
不同的电池片时
-
00:15:33.87 - 00:15:34.65 9
可以采用一些其他的
-
00:15:34.72 - 00:15:35.43 4
仿真思路
-
00:15:39.71 - 00:15:43.13 8
因此只需总结一下
-
00:15:43.13 - 00:15:43.74 16
固体模型 复合Tshells模型
-
00:15:43.81 - 00:15:47.24 11
宏模型和无网格模型之间
-
00:15:47.24 - 00:15:47.70 5
的不同模型
-
00:15:47.70 - 00:15:50.29 15
我们可以构建不同的电池几何结构
-
00:15:50.29 - 00:15:52.46 8
其中一些用于电池
-
00:15:52.46 - 00:15:55.21 9
一些更多地用于模块
-
00:15:55.21 - 00:15:55.27 2
还有
-
00:15:55.33 - 00:15:57.71 7
一些用于电池组
-
00:15:57.71 - 00:16:00.44 12
所有这些模型均可以连接到
-
00:16:00.44 - 00:16:01.04 5
内部短路的
-
00:16:01.11 - 00:16:03.84 13
外部电路 除了无网格模型外
-
00:16:03.84 - 00:16:04.20 10
所有的其他模型都可以
-
00:16:04.26 - 00:16:06.99 12
实现这一点 您还可以研究
-
00:16:06.99 - 00:16:07.23 11
所有这些模型的外部短路
-
00:16:07.23 - 00:16:10.43 3
它们都
-
00:16:10.50 - 00:16:12.07 7
与热力学相耦合
-
00:16:12.07 - 00:16:15.20 6
我没有添加与
-
00:16:15.27 - 00:16:15.70 9
ICFD耦合的一行
-
00:16:15.70 - 00:16:16.77 7
但本应该要加上
-
00:16:16.77 - 00:16:19.18 7
因为现在主要是
-
00:16:19.25 - 00:16:19.89 2
为了
-
00:16:19.89 - 00:16:22.29 16
比较宏模型 复合Tshell模型
-
00:16:22.29 - 00:16:24.61 5
和固体模型
-
00:16:24.61 - 00:16:25.73 2
当然
-
00:16:25.73 - 00:16:28.38 10
如果只是流经导电表面
-
00:16:28.46 - 00:16:29.91 5
无网格模型
-
00:16:29.91 - 00:16:34.83 12
可以像上一张幻灯片显示的
-
00:16:34.83 - 00:16:35.49 2
一样
-
00:16:35.49 - 00:16:36.56 2
总之
-
00:16:36.56 - 00:16:38.66 16
LS-DYNA是一个多物理场软件
-
00:16:38.66 - 00:16:41.49 10
因此研发出一个耦合了
-
00:16:41.49 - 00:16:42.69 2
机械
-
00:16:42.75 - 00:16:43.26 1
热
-
00:16:43.26 - 00:16:46.95 9
电气和电化学响应的
-
00:16:46.95 - 00:16:48.48 8
电池安全建模框架
-
00:16:48.48 - 00:16:52.11 4
该研发是
-
00:16:52.11 - 00:16:52.19 1
与
-
00:16:52.27 - 00:16:52.51 1
呃
-
00:16:52.51 - 00:16:53.77 11
行业合作伙伴合作完成的
-
00:16:53.77 - 00:16:56.48 5
然后提出了
-
00:16:56.55 - 00:16:57.93 8
所有这些研发建议
-
00:16:57.93 - 00:17:00.93 9
但可供所有用户使用
-
00:17:00.93 - 00:17:03.29 8
据我们所知 没有
-
00:17:03.29 - 00:17:03.98 14
其他软件具有这种多物理场功能
-
00:17:03.98 - 00:17:06.92 8
尤其是没有在机械
-
00:17:06.92 - 00:17:08.10 11
和其他部分之间进行耦合
-
00:17:08.10 - 00:17:11.04 15
对于蓄电池崩溃 目前所做的努力
-
00:17:11.04 - 00:17:11.50 6
是为了将模型
-
00:17:11.56 - 00:17:14.51 9
与用户定义的子程序
-
00:17:14.51 - 00:17:15.36 4
耦合起来
-
00:17:15.42 - 00:17:16.86 7
以超越等效电路
-
00:17:16.86 - 00:17:19.72 14
因此需要通过用户映射类子程序
-
00:17:19.72 - 00:17:23.40 11
而目前其已经开始提供了
-
00:17:23.49 - 00:17:26.57 9
仿真求解器本身依靠
-
00:17:26.57 - 00:17:27.87 7
实验测试来描述
-
00:17:27.93 - 00:17:29.92 5
他们的方程
-
00:17:29.92 - 00:17:32.99 6
因此我们认为
-
00:17:32.99 - 00:17:33.47 2
整个
-
00:17:33.54 - 00:17:36.61 6
行业和学术界
-
00:17:36.61 - 00:17:38.18 10
都需要努力来加强我们
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对此的集体知识
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这是一个难题
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在此 非常感谢大家
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祝大家今天过得开心
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再见
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My name is Pierre L'Eplattenier. I work at LST and
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I will talk to you today about the path
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towards
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including batteries in electric or hybrid car
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crash simulations with
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LS-DYNA
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and I'd like to thank my colleague
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Inaki Caldichoury
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who's working on this subject with me
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and helping prepare this talk
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So just a little bit of context about
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automotive safety.
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In 1966,
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the National traffic and Motor Vehicle
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Safety Act
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was enacted in the United States,
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giving new standards for motor vehicle and
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road traffic safety.
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And as you can see,
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on the curve on the right.
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Since then,
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the number of death on the car crashes
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gas decreased by quite a bit.
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Uh, thanks largely to seatbelts,
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airbags,
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and general knowledge came from car crash
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tests.
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And use of simulation in the past couple of
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decades
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00:00:53.47 - 00:00:54.28 9
has been,
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uh, has helped a lot
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00:00:57.80 - 00:01:01.28 36
to getting a better comprehension of
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00:01:01.28 - 00:01:01.82 7
the car
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00:01:01.90 - 00:01:05.38 45
crash events and among the various commercial
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offers available.
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LS-DYNA
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has been widely accepted by the
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automotive
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community.
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Now recently a new type of locomotion has
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reemerged because
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actually it was one of the first at the
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beginning
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of the 20th century.
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It is the electric car and
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the range increase that we have seen in the
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recent
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years will make it more and more difficult
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for car
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users to protect their batteries in rigid
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containers,
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and so the simulation will probably help
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quite a lot
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in the battery safety.
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Uh,
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and so these batteries they bring new
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challenges,
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as you've seen on the news,
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very often when battery and electric car
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hybrid car gets
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into a crash.
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You can see pretty large fires getting out,
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so how confident are we that battery will not
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catch
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into fire after a crash?
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How safe are we as consumers ?
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As engineers can we anticipate these problems?
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Where is your degree of understanding?
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How much should we protect the battery?
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And that's where the simulation can help
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quite a
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bit.
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Now simulating a battery crash is quite
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challenging.
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First of all,
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the physics is very complex and it's
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a multi physics which couples tightly
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mechanical electromagnetics,
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electrochemistry and thermal.
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There's a wide range of length scale
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with the battery being of the size around
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1 meter
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or so,
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while the individual layers in a cell have
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thickness around
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tens of micrometers.
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00:02:55.94 - 00:02:59.88 34
And this is the level at which the
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internal
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shorts happen and trigger the big thermal
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runaway battery catching
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into fire.
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00:03:06.80 - 00:03:10.67 41
There's also a wide range of time scales,
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from crash in millisecond that happen in the
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millisecond to
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thermal runaway fire and explosion that can
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take minutes to
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hours or even days.
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00:03:21.19 - 00:03:27.43 42
So luckily, withLS-DYNA now we already had
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tightly coupling between mechanics electrical
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thermal and what we
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00:03:32.04 - 00:03:32.55 6
had to
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work was the electrochemistry on the bottom
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right here.
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00:03:36.60 - 00:03:39.87 40
So now we have a module that couples the
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mechanical
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where the displacement can be given to the
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electrical part
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and taken into account by the electrochemical
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part and I
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will come back to that.
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00:03:50.47 - 00:03:53.74 43
We use equivalent circuit for that part and
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00:03:53.74 - 00:03:54.03 5
so we
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00:03:54.10 - 00:03:57.38 43
can have the mechanical deformation trigger
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00:03:57.38 - 00:03:57.60 3
the
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00:03:57.60 - 00:03:58.77 15
Internet shorts
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The electrical and electrochemical are
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00:04:02.30 - 00:04:03.16 16
coupled with the
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00:04:03.24 - 00:04:03.86 8
thermal,
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00:04:03.86 - 00:04:07.40 43
so we give the Joule heating to the thermal
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00:04:07.40 - 00:04:07.55 3
and
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00:04:07.63 - 00:04:10.78 39
we get back the temperature parameters.
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And,
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00:04:11.18 - 00:04:11.57 3
uh,
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the thermal and mechanical also coupled with
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00:04:16.07 - 00:04:16.47 3
the
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mechanics, and more recently,
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we added the ICFD module into that
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whole chain where the thermal and the
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00:04:27.46 - 00:04:27.75 4
ICFD
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communicate by the conjugate heat transfer
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solver and more recently,
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the CFD and the electrical they can
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communicate directly so
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we can have a conducting fluids and we will
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00:04:41.78 - 00:04:41.96 3
see
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00:04:42.04 - 00:04:44.10 25
briefly that a bit later.
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Now,
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we have four models depending on the scale
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or
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the detail that the user wants to study.
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00:04:50.20 - 00:04:53.15 47
So as I said, the internal short they happen at
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the cell level and they are the root cause
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for
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internal runaway.
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00:04:57.47 - 00:05:00.42 43
So it is important to understand the effect
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00:05:00.42 - 00:05:00.62 4
of a
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00:05:00.68 - 00:05:03.64 45
mechanical or thermal abuse on a single cell,
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00:05:03.64 - 00:05:06.62 41
which will probably depend on the type of
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00:05:06.62 - 00:05:06.75 5
cell.
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00:05:06.75 - 00:05:09.49 42
So for that we have what we call the solid
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00:05:09.56 - 00:05:12.50 41
element model where all of the layers are
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made using
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00:05:13.02 - 00:05:15.05 30
solid elements and the same as
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is used for the mechanics,
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00:05:16.71 - 00:05:19.10 19
the thermal and EM.
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00:05:19.10 - 00:05:22.40 43
And we also have the composite Tshell model
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where the
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mechanical is modeled using composite
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Tshells and the EM
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and thermal still use an underlying solid
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00:05:31.08 - 00:05:31.74 12
mesh that we
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revealed behind the scenes and it allows to
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00:05:35.06 - 00:05:35.65 9
do faster
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00:05:35.72 - 00:05:39.04 45
run with less element and solid element model
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00:05:39.04 - 00:05:39.12 1
.
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00:05:39.12 - 00:05:42.44 44
Both of these models are for typical studies
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at the
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level of the cell of the module,
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00:05:45.33 - 00:05:48.89 29
maybe not much larger models.
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00:05:48.89 - 00:05:51.82 42
So modeling a full battery at the level of
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each
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cell layer would be very expensive
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computationally.
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00:05:55.33 - 00:05:58.26 44
So we created the macro model that we called
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00:05:58.26 - 00:05:58.52 8
"batmac"
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that allows using the information from a
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00:06:01.51 - 00:06:02.23 11
single cell
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00:06:02.29 - 00:06:02.68 6
study,
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00:06:02.68 - 00:06:05.62 36
and in particular information of the
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00:06:05.62 - 00:06:06.27 17
internal shots in
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00:06:06.33 - 00:06:08.68 36
a full battery model in a car crash,
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00:06:08.68 - 00:06:11.17 30
and so that's the macro model.
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That's also can do internal and external
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shorts,
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but that's available now for pack or a battery.
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So for this model we are one or a few
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solid element through the thickness for the
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mechanics EM and
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the thermal and two fields each at
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00:06:26.14 - 00:06:26.69 12
the positive
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and negative current collectors.
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And we also have the meshless
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model where we don't care about the what's
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happening internally
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in the cell,
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00:06:37.14 - 00:06:40.63 39
but we still have all of the equivalent
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00:06:40.63 - 00:06:41.10 11
circuit and
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00:06:41.17 - 00:06:44.59 35
the energy and so forth that can be
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00:06:44.67 - 00:06:46.61 22
be output by the cell.
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That's mostly for external shorts
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00:06:50.32 - 00:06:54.14 43
All of these models are based on equivalent
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00:06:54.14 - 00:06:54.74 8
circuit,
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00:06:54.74 - 00:06:58.52 40
so we use distributed random model where
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00:06:58.52 - 00:06:59.95 21
instead of simulating
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00:07:00.03 - 00:07:03.81 42
the electrochemistry happening between the
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00:07:03.81 - 00:07:06.42 33
anode and cathode and separators,
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00:07:06.42 - 00:07:10.22 41
we use equivalent circuits that have been
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00:07:10.22 - 00:07:10.81 10
used a lot
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00:07:10.90 - 00:07:12.67 21
in the battery model.
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00:07:12.67 - 00:07:15.93 38
But we use them in a distributed mode,
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00:07:15.93 - 00:07:19.72 43
meaning that we have one equivalent circuit
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00:07:19.72 - 00:07:20.82 14
for each node.
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00:07:20.82 - 00:07:23.42 36
In the positive and negative current
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collector,
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00:07:23.54 - 00:07:26.11 36
so each node of the positive current
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00:07:26.11 - 00:07:26.92 22
collector is connected
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00:07:26.97 - 00:07:29.55 44
to the opposite node of the negative current
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collector.
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00:07:30.12 - 00:07:32.67 26
Such as a Randles circuit.
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00:07:32.67 - 00:07:35.61 45
So the advantage of this distributing circuit
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00:07:35.61 - 00:07:36.53 13
model is that
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00:07:36.59 - 00:07:39.40 43
they are not too expensive computationally.
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00:07:39.40 - 00:07:42.37 38
They can accurately reproduce the main
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00:07:42.37 - 00:07:43.16 18
feature of a cell,
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00:07:43.16 - 00:07:44.67 23
electrical and thermal.
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00:07:44.67 - 00:07:46.63 16
They are easy to
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00:07:46.69 - 00:07:49.63 44
get the cell parameters from the voltage and
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00:07:49.63 - 00:07:51.00 21
current measurements.
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00:07:51.00 - 00:07:53.94 43
It's simple to electrically connect them to
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00:07:53.94 - 00:07:55.24 21
external circuit like
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00:07:55.30 - 00:07:58.24 28
connector buses and to model
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00:07:58.24 - 00:07:59.02 19
external shorts and
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00:07:59.08 - 00:08:02.02 39
the main thing was the ability to model
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00:08:02.02 - 00:08:02.47 8
internal
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00:08:02.47 - 00:08:02.92 7
shorts.
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00:08:02.92 - 00:08:05.67 42
Like on the bottom right where if you have
-
00:08:05.74 - 00:08:08.62 42
deformations of the current collectors you
-
00:08:08.62 - 00:08:09.71 19
can replace some of
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00:08:09.77 - 00:08:10.48 11
the Randles
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00:08:10.48 - 00:08:13.21 46
circuits by just internal short resistance and
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00:08:13.21 - 00:08:13.57 7
you can
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00:08:13.63 - 00:08:16.36 27
have the value of the short
-
00:08:16.36 - 00:08:17.09 19
resistant depending
-
00:08:17.15 - 00:08:19.88 37
on the local mechanical parameters or
-
00:08:19.88 - 00:08:20.92 24
deformations of the run.
-
00:08:24.22 - 00:08:27.11 37
To deal with the different timescales
-
00:08:27.11 - 00:08:27.43 6
we do,
-
00:08:27.43 - 00:08:30.29 45
usually the mechanics EM and the thermal with
-
00:08:30.29 - 00:08:30.93 9
the usual
-
00:08:30.99 - 00:08:33.85 45
crash time step during the milliseconds or so
-
00:08:33.85 - 00:08:34.55 10
crash time
-
00:08:34.61 - 00:08:37.47 45
we get the deformations of the short and then
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00:08:37.47 - 00:08:37.66 2
we
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00:08:37.66 - 00:08:40.52 42
continue the run by freezing the mechanics
-
00:08:40.52 - 00:08:40.96 9
and we do
-
00:08:41.03 - 00:08:43.89 43
only EMand thermal with now time steps much
-
00:08:43.89 - 00:08:44.27 6
larger
-
00:08:44.33 - 00:08:47.19 42
around the second or so to let the battery
-
00:08:47.19 - 00:08:47.63 9
discharge
-
00:08:47.63 - 00:08:50.57 41
through the shots and get the temperature
-
00:08:50.57 - 00:08:51.42 16
increase and let
-
00:08:51.48 - 00:08:54.16 40
it run for the physical minutes or hours
-
00:08:54.16 - 00:08:56.71 35
if you need to. For the simulation,
-
00:08:56.71 - 00:08:59.30 44
the EM and the thermal are not too sensitive
-
00:08:59.30 - 00:08:59.36 2
to
-
00:08:59.41 - 00:09:02.00 44
the time step apart from getting the correct
-
00:09:02.00 - 00:09:02.98 17
discretization of
-
00:09:03.04 - 00:09:05.51 43
battery discharge and temperature increase,
-
00:09:05.51 - 00:09:09.04 44
so it's OK to switch from the millisecond to
-
00:09:09.04 - 00:09:09.28 3
the
-
00:09:09.36 - 00:09:11.48 27
second time frame for this.
-
00:09:11.48 - 00:09:14.39 38
And now, I'll show you a few examples.
-
00:09:14.39 - 00:09:18.63 42
This is an external short example that was
-
00:09:18.63 - 00:09:19.57 12
performed by
-
00:09:19.66 - 00:09:22.49 29
Ford and where they connected
-
00:09:22.49 - 00:09:22.71 3
uh,
-
00:09:22.71 - 00:09:26.00 41
a little module of five cells together by
-
00:09:26.00 - 00:09:26.15 4
some
-
00:09:26.22 - 00:09:29.51 42
buses and they just came and connected the
-
00:09:29.51 - 00:09:29.95 8
plus and
-
00:09:30.03 - 00:09:33.25 44
minus of the bus and let the current flow in
-
00:09:33.25 - 00:09:36.54 42
that external short and they looked at the
-
00:09:36.54 - 00:09:37.85 20
temperature increase
-
00:09:37.93 - 00:09:41.22 45
at different location in the buses and in the
-
00:09:41.22 - 00:09:41.66 5
cells
-
00:09:41.73 - 00:09:45.02 36
themselves and compare that with the
-
00:09:45.02 - 00:09:46.04 22
experiment and you can
-
00:09:46.04 - 00:09:50.52 45
see under the right graph that matches pretty
-
00:09:50.52 - 00:09:51.82 12
good between
-
00:09:51.92 - 00:09:52.72 8
the two.
-
00:09:52.72 - 00:09:56.45 43
This is another example of an external shot
-
00:09:56.45 - 00:09:56.87 5
where
-
00:09:56.87 - 00:10:00.63 35
now it's a 20 cell module that were
-
00:10:00.63 - 00:10:00.71 9
connected
-
00:10:00.79 - 00:10:04.39 43
on some buses and a plate came and made all
-
00:10:04.47 - 00:10:06.98 30
of these buses crash together.
-
00:10:06.98 - 00:10:10.38 36
Deform and come in contact together.
-
00:10:10.38 - 00:10:13.40 38
And so the current now is doesn't flow
-
00:10:13.40 - 00:10:13.73 11
through the
-
00:10:13.80 - 00:10:14.74 14
cells anymore,
-
00:10:14.74 - 00:10:18.16 38
but can flow through the short circuit
-
00:10:18.16 - 00:10:19.46 23
between these different
-
00:10:19.53 - 00:10:22.96 41
buses there that come in contact and they
-
00:10:22.96 - 00:10:23.49 9
looked at
-
00:10:23.57 - 00:10:26.99 39
the elevation of the temperature of the
-
00:10:26.99 - 00:10:27.68 14
external shot.
-
00:10:27.68 - 00:10:30.67 38
This was done with the meshless model.
-
00:10:30.67 - 00:10:33.20 32
So here are some other examples.
-
00:10:33.20 - 00:10:36.67 41
On the left it's external short where the
-
00:10:36.67 - 00:10:37.82 13
cylinder tube
-
00:10:37.90 - 00:10:41.37 44
the conducting cylinder tube comes and makes
-
00:10:41.37 - 00:10:42.37 12
the two tabs
-
00:10:42.45 - 00:10:45.92 41
into contact and that makes some external
-
00:10:45.92 - 00:10:47.46 25
short and the temperature
-
00:10:47.46 - 00:10:49.92 32
elevation. In the in the middle,
-
00:10:49.92 - 00:10:52.13 24
that's sphere falling on
-
00:10:52.13 - 00:10:55.30 34
ten cells module and creating some
-
00:10:55.39 - 00:10:59.36 44
internal shorts and that's using the feature
-
00:10:59.36 - 00:10:59.81 6
model.
-
00:10:59.81 - 00:11:03.38 44
And on the right it's a internal short using
-
00:11:03.38 - 00:11:03.54 3
the
-
00:11:03.62 - 00:11:06.87 42
"batmac" model where we have a big pack of
-
00:11:06.95 - 00:11:10.52 43
50 cells that come and gets impacted by one
-
00:11:10.52 - 00:11:10.60 2
of
-
00:11:10.60 - 00:11:14.85 39
its corner and it creates some internal
-
00:11:14.85 - 00:11:16.45 22
shorts and temperature
-
00:11:16.54 - 00:11:17.49 10
elevation.
-
00:11:17.49 - 00:11:21.71 42
So these are examples of what can be done.
-
00:11:21.71 - 00:11:28.20 45
Now some more recent development that we did.
-
00:11:28.20 - 00:11:30.86 7
If the.
-
00:11:30.86 - 00:11:31.09 3
OK,
-
00:11:31.09 - 00:11:32.11 12
it's coming.
-
00:11:32.11 - 00:11:34.71 32
So it's the nail penetration so.
-
00:11:37.98 - 00:11:39.95 9
We got a.
-
00:11:41.99 - 00:11:44.45 28
penetration with simulation.
-
00:11:44.45 - 00:11:48.25 41
So this is example for a nail penetrating
-
00:11:48.35 - 00:11:51.54 32
30 cell back and creating holes.
-
00:11:51.54 - 00:11:54.23 29
Around that whole some shorts
-
00:11:54.23 - 00:11:57.24 42
are created and so we get these shorts and
-
00:11:57.24 - 00:11:57.97 11
temperature
-
00:11:58.04 - 00:11:58.71 10
elevation.
-
00:11:58.71 - 00:12:01.36 41
So we use the "batmac" model here for the
-
00:12:01.42 - 00:12:04.40 45
first 10 cells because that's about where the
-
00:12:04.40 - 00:12:05.13 10
nail stops
-
00:12:05.20 - 00:12:08.18 35
during its penetration and use some
-
00:12:09.37 - 00:12:12.06 40
the rest so that we still get all of the
-
00:12:12.13 - 00:12:12.60 7
energy,
-
00:12:12.60 - 00:12:15.61 43
the current and the voltage coming from all
-
00:12:15.61 - 00:12:15.94 6
of the
-
00:12:16.01 - 00:12:16.81 12
other cells.
-
00:12:16.81 - 00:12:19.82 37
But we didn't care too much about the
-
00:12:19.82 - 00:12:20.22 13
internal part
-
00:12:20.29 - 00:12:21.09 12
of the cell,
-
00:12:21.09 - 00:12:23.93 20
so that's available.
-
00:12:23.93 - 00:12:24.13 3
Uh,
-
00:12:24.13 - 00:12:27.14 41
also something new that we did is thermal
-
00:12:27.14 - 00:12:27.67 10
management
-
00:12:27.74 - 00:12:30.49 39
with coupling between the batmac model,
-
00:12:30.49 - 00:12:32.54 30
the thermal and the CFD model,
-
00:12:32.54 - 00:12:34.60 24
so that's an example of
-
00:12:36.90 - 00:12:40.51 45
a pack of 96 cylindrical cells that is placed
-
00:12:40.51 - 00:12:40.75 2
as
-
00:12:40.83 - 00:12:44.37 44
you can see on the top left picture and they
-
00:12:44.45 - 00:12:48.06 38
are different way of cooling that pack
-
00:12:48.06 - 00:12:48.78 15
because just in
-
00:12:48.78 - 00:12:50.86 23
normal use it heats up.
-
00:12:50.86 - 00:12:54.47 41
So there is either direct air flow so air
-
00:12:54.47 - 00:12:54.79 7
cooling
-
00:12:54.87 - 00:12:58.49 39
that flows directly through these cells
-
00:12:58.49 - 00:12:59.61 17
and then there is
-
00:12:59.69 - 00:13:03.31 44
indirect liquid cooling by the bottom plate.
-
00:13:03.31 - 00:13:06.96 41
So on that bottom template you can have a
-
00:13:06.96 - 00:13:07.13 6
little
-
00:13:07.13 - 00:13:10.84 42
tube where some water can flow through the
-
00:13:10.84 - 00:13:11.33 8
tube and
-
00:13:11.42 - 00:13:15.13 39
then the whole package cool down by the
-
00:13:15.13 - 00:13:15.30 7
bottom.
-
00:13:15.30 - 00:13:19.20 43
So we did some simulation with that and you
-
00:13:19.20 - 00:13:19.37 3
can
-
00:13:19.46 - 00:13:21.28 21
see for example here.
-
00:13:21.28 - 00:13:25.15 44
The difference between no cooling and liquid
-
00:13:25.15 - 00:13:26.35 14
cooling by the
-
00:13:26.44 - 00:13:30.31 36
bottom plate and the you can see the
-
00:13:30.31 - 00:13:30.83 13
repetition of
-
00:13:30.91 - 00:13:34.78 36
the temperature in the back and also
-
00:13:34.78 - 00:13:34.95 3
the
-
00:13:34.95 - 00:13:38.84 45
we gained quite a bit because with no cooling
-
00:13:38.84 - 00:13:39.10 2
we
-
00:13:39.19 - 00:13:43.07 45
module heated up to up to 43 degrees Celsius,
-
00:13:43.07 - 00:13:45.85 27
whereas with liquid cooling
-
00:13:45.85 - 00:13:48.54 24
heated up to 24 degrees.
-
00:13:48.54 - 00:13:50.67 3
Uh.
-
00:13:50.67 - 00:13:52.48 26
Now that's the same thing,
-
00:13:52.48 - 00:13:55.53 45
but with air cooling on the left and with air
-
00:13:55.60 - 00:13:57.84 33
plus liquid cooling on the right,
-
00:13:57.84 - 00:14:00.83 45
and you can see again and again that you have
-
00:14:00.90 - 00:14:03.95 45
by using the different kind of cooling system
-
00:14:03.95 - 00:14:04.02 1
.
-
00:14:04.02 - 00:14:07.39 45
So thermal management is is available also in
-
00:14:07.39 - 00:14:07.99 7
LS-DYNA
-
00:14:08.07 - 00:14:09.50 18
with this coupling
-
00:14:09.50 - 00:14:13.58 28
between EM thermal and ICFD.
-
00:14:13.58 - 00:14:15.71 3
Um,
-
00:14:15.71 - 00:14:18.68 43
And the nice thing also is that you can use
-
00:14:18.75 - 00:14:20.07 19
the same mesh here.
-
00:14:20.07 - 00:14:23.17 43
Of course you wouldn't do a battery cooling
-
00:14:23.17 - 00:14:23.99 13
simulation at
-
00:14:24.06 - 00:14:26.54 36
the same time as a crush experiment,
-
00:14:26.54 - 00:14:30.14 41
but you can use the same mesh you use for
-
00:14:30.22 - 00:14:33.75 38
thermal management later in the crash.
-
00:14:33.75 - 00:14:34.41 3
Uh.
-
00:14:37.45 - 00:14:41.87 41
Then another example that I would like to
-
00:14:41.87 - 00:14:42.26 7
show if
-
00:14:42.36 - 00:14:42.95 6
my OK.
-
00:14:42.95 - 00:14:47.17 43
So now we also have the ability to have the
-
00:14:47.27 - 00:14:49.32 22
coupling between ICFD,
-
00:14:49.32 - 00:14:51.77 30
and the EM and battery module,
-
00:14:51.77 - 00:14:55.19 34
where we can have conducting water
-
00:14:55.29 - 00:14:57.05 18
flowing over cell.
-
00:14:57.05 - 00:15:01.41 36
Here that's conducting where that is
-
00:15:01.41 - 00:15:02.97 22
flowing over the buses
-
00:15:03.06 - 00:15:07.43 40
connecting the cells and it creates some
-
00:15:07.43 - 00:15:08.50 15
short circuits.
-
00:15:08.50 - 00:15:11.83 45
Because now the current can flow from one tab
-
00:15:11.83 - 00:15:12.05 2
to
-
00:15:12.12 - 00:15:15.46 46
the next through the water which is conducting
-
00:15:15.46 - 00:15:15.61 1
,
-
00:15:15.61 - 00:15:18.66 43
and change completely the repetition of the
-
00:15:18.66 - 00:15:19.61 15
current and the
-
00:15:19.67 - 00:15:22.73 42
temperature in fact and you can see on the
-
00:15:22.73 - 00:15:23.00 5
right
-
00:15:23.06 - 00:15:26.12 41
that the state of charge diminishes quite
-
00:15:26.12 - 00:15:26.79 14
a lot when you
-
00:15:26.79 - 00:15:27.57 11
have these,
-
00:15:27.57 - 00:15:27.86 3
Uh,
-
00:15:27.86 - 00:15:30.61 38
when you have the water connecting the
-
00:15:30.69 - 00:15:33.87 44
different tabs so that's some other ideas of
-
00:15:33.87 - 00:15:34.65 19
simulation that are
-
00:15:34.72 - 00:15:35.43 10
available.
-
00:15:39.71 - 00:15:43.13 41
So just a summary of the different models
-
00:15:43.13 - 00:15:43.74 11
between the
-
00:15:43.81 - 00:15:47.24 39
Solid Composite Tshells Macro model and
-
00:15:47.24 - 00:15:47.70 9
Meshless.
-
00:15:47.70 - 00:15:50.29 37
We can have different cell geometrys,
-
00:15:50.29 - 00:15:52.46 35
some of them are used for the cell,
-
00:15:52.46 - 00:15:55.21 42
some of them are used more for the modules
-
00:15:55.21 - 00:15:55.27 3
and
-
00:15:55.33 - 00:15:57.71 39
some of them you will use for the pack.
-
00:15:57.71 - 00:16:00.44 38
All of them you can have connection to
-
00:16:00.44 - 00:16:01.04 8
external
-
00:16:01.11 - 00:16:03.84 43
circuit for internal shorts all of them can
-
00:16:03.84 - 00:16:04.20 7
do that
-
00:16:04.26 - 00:16:06.99 43
except for the meshless you can do external
-
00:16:06.99 - 00:16:07.23 5
short
-
00:16:07.23 - 00:16:10.43 45
for all of them and they are all coupled with
-
00:16:10.50 - 00:16:12.07 22
the thermal mechanics.
-
00:16:12.07 - 00:16:15.20 45
And I didn't add a line for the coupling with
-
00:16:15.27 - 00:16:15.70 5
ICFD,
-
00:16:15.70 - 00:16:16.77 15
which I should,
-
00:16:16.77 - 00:16:19.18 29
but they are pretty much just
-
00:16:19.25 - 00:16:19.89 7
for now
-
00:16:19.89 - 00:16:22.29 34
the Macro model, Composite Tshells
-
00:16:22.29 - 00:16:24.61 10
and Solid.
-
00:16:24.61 - 00:16:25.73 14
And of course,
-
00:16:25.73 - 00:16:28.38 17
the Meshless like
-
00:16:28.46 - 00:16:29.91 17
on the last slide
-
00:16:29.91 - 00:16:34.83 43
if you just have a flow over the conducting
-
00:16:34.83 - 00:16:35.49 8
surface.
-
00:16:35.49 - 00:16:36.56 17
So in conclusion,
-
00:16:36.56 - 00:16:38.66 31
LS-DYNA is a multiphysics code,
-
00:16:38.66 - 00:16:41.49 41
so a framework of battery safety modeling
-
00:16:41.49 - 00:16:42.69 22
that couple mechanical
-
00:16:42.75 - 00:16:43.26 8
thermal,
-
00:16:43.26 - 00:16:46.95 40
electrical and electrochemical responses
-
00:16:46.95 - 00:16:48.48 19
has been developed.
-
00:16:48.48 - 00:16:52.11 40
The development is done in collaboration
-
00:16:52.11 - 00:16:52.19 4
with
-
00:16:52.27 - 00:16:52.51 3
uh,
-
00:16:52.51 - 00:16:53.77 20
industrial partners,
-
00:16:53.77 - 00:16:56.48 28
that was then that suggested
-
00:16:56.55 - 00:16:57.93 22
all these development,
-
00:16:57.93 - 00:17:00.93 39
but it's available to all of the users.
-
00:17:00.93 - 00:17:03.29 39
To our knowledge no other code has this
-
00:17:03.29 - 00:17:03.98 24
multiphysics capability,
-
00:17:03.98 - 00:17:06.92 39
especially not the coupling between the
-
00:17:06.92 - 00:17:08.10 22
mechanics and the rest
-
00:17:08.10 - 00:17:11.04 36
for battery crash. Efforts are being
-
00:17:11.04 - 00:17:11.50 7
done in
-
00:17:11.56 - 00:17:14.51 43
order to couple the model with user defined
-
00:17:14.51 - 00:17:15.36 14
subroutines to
-
00:17:15.42 - 00:17:16.86 20
go beyond equivalent
-
00:17:16.86 - 00:17:19.72 47
circuits, So through user map like subroutines.
-
00:17:19.72 - 00:17:23.40 45
So it's it's already starting to be available
-
00:17:23.40 - 00:17:23.49 1
.
-
00:17:23.49 - 00:17:26.57 45
And the simulation solvers themselves rely on
-
00:17:26.57 - 00:17:27.87 19
experiment tests to
-
00:17:27.93 - 00:17:29.92 29
characterize their equations,
-
00:17:29.92 - 00:17:32.99 45
so there's a effort we believe that is needed
-
00:17:32.99 - 00:17:33.47 6
across
-
00:17:33.54 - 00:17:36.61 42
the industries and academia to bolster our
-
00:17:36.61 - 00:17:38.18 26
collective knowledge about
-
00:17:38.24 - 00:17:38.59 5
that.
-
00:17:38.59 - 00:17:41.12 26
It is a difficult problem.
-
00:17:41.12 - 00:17:44.75 43
And on that, thank you very much and have a
-
00:17:44.83 - 00:17:45.59 9
good day.
-
00:17:45.59 - 00:17:46.26 8
Bye bye.