Extreme deformations of magneto- and electro-active membranes: A framework to model instabilities due to large multi-physics loads in thin structures

当结构发生大变形时，结构在失稳(或分叉)点处的响应会发生突变。结构失稳往往导致机械故障，因此在基于混凝土和金属等材料的工程设计中传统上是避免的。另一方面，软弹性体可以进行大的可逆变形，而不会发生故障。这种情况下的分叉或失稳现象可用于驱动机构和能量转换机构的设计。磁流变弹性体(MRE)和电活性聚合物(EAP)是一种新型的软智能材料，可以在电磁场的作用下变形，因此用它们制造的器件提供了多种控制机制。其工业应用的一个关键限制因素是对由于复杂的非线性多物理耦合而导致的极端载荷下的不稳定性缺乏了解。在这个项目中，我们建议加强对薄机电和磁机械结构中的不稳定性现象的理解，并提供一个数学和计算框架来模拟这一过程。这将使我们能够研究和模拟MRE和EAP薄膜中的极端变形，从而显著改进为软机器人执行器、传感器、可变形透镜和波能发生器的工程设计提供信息的工具。

When structures undergo large deformation, there is an abrupt change in their structural response at the instability (or bifurcation) point. Structural instability often leads to mechanical failure and hence has been traditionally avoided in engineering design based on materials such as concrete and metal. Soft elastomers, on the other hand, can undergo large reversible deformation without failure. The bifurcation or instability phenomenon in this case can be used to our advantage in the design of actuation and energy conversion mechanisms. Magneto-rheological elastomers (MREs) and electro-active polymers (EAPs) are new types of soft smart materials that can deform in the presence of electromagnetic fields and therefore devices made using them provide multi-control mechanisms. A key limiting factor in their industry adoption is a poor understanding of instability under extreme loads due to complex nonlinear multi-physics coupling.In this project, we propose to develop an enhanced understanding of the instability phenomenon in thin electro-mechanical and magneto-mechanical structures and deliver a mathematical and computational framework to model this process. This will allow us to investigate and simulate extreme deformation in MRE and EAP membranes, thereby significantly improving the tools that inform engineering design of soft robotic actuators, sensors, deformable lenses, and wave energy generators.