We present a Matlab code for modelling and topology optimization of hyperelastic structures, including contact modelled by the Third Medium Contact (TMC) approach. By using the so-called HuHu-regularization we penalize the skew distortion of the bilinear finite elements discretizing void regions, thus promoting convergence of the nonlinear solver. First, we show how this method is implemented in a compact code, allowing to simulate contact and force transfer in hyperelastic structures. We then solve two topology optimization problems for minimum end-compliance of structures exhibiting contact. In the first example, contact happens at the supported boundary, while the second features self-contact. The Matlab scripts that replicate the results are included, and we discuss some possible extensions to more general problems.

翻译：我们提出了一种用于超弹性结构建模与拓扑优化的Matlab代码，其中采用第三介质接触（TMC）方法模拟接触行为。通过使用所谓的HuHu正则化技术，对离散化空隙区域的双线性有限单元的扭曲变形施加惩罚，从而促进非线性求解器的收敛。首先，我们展示了该方法如何在紧凑的代码框架中实现，使其能够模拟超弹性结构中的接触与力传递。随后，针对具有接触特性的结构，我们求解了两个最小端点柔度拓扑优化问题。第一个案例中，接触发生在支撑边界上；第二个案例则涉及自接触问题。文中附带了可复现计算结果的Matlab脚本，并讨论了该方法向更广泛问题扩展的潜在可能性。