A topology optimization approach for designing large deformation contact-aided shape morphing compliant mechanisms is presented. Such mechanisms can be used in varying operating conditions. Design domains are described by regular hexagonal elements. Negative circular masks are employed to perform dual task, i.e., to decide material states of each element and also, to generate rigid contact surfaces. Each mask is characterized by five design variables, which are mutated by a zero-order based hill-climbing optimizer. Geometric and material nonlinearities are considered. Continuity in normals to boundaries of the candidate designs is ensured using a boundary resolution and smoothing scheme. Nonlinear mechanical equilibrium equations are solved using the Newton-Raphson method. An updated Lagrange approach in association with segment-to-segment contact method is employed for the contact formulation. Both mutual and self contact modes are permitted. Efficacy of the approach is demonstrated by designing four contact-aided shape morphing compliant mechanisms for different desired curves. Performance of the deformed profiles is verified using a commercial software. The effect of frictional contact surface on the actual profile is also studied

中文翻译：

---

大变形接触辅助形状变形柔顺机构拓扑优化研究

提出了一种用于设计大变形接触辅助形状变形柔顺机构的拓扑优化方法。这种机制可用于不同的操作条件。设计域由正六边形元素描述。负圆形掩模用于执行双重任务，即决定每个元素的材料状态，以及生成刚性接触面。每个掩码由五个设计变量表征，这些变量由基于零阶的爬山优化器进行变异。考虑了几何和材料非线性。使用边界分辨率和平滑方案确保候选设计边界法线的连续性。非线性力学平衡方程使用 Newton-Raphson 方法求解。与段到段接触方法相关联的更新的拉格朗日方法用于接触公式。允许相互接触和自接触模式。通过为不同的所需曲线设计四种接触辅助形状变形柔顺机制，证明了该方法的有效性。使用商业软件验证变形轮廓的性能。摩擦接触面对实际轮廓的影响也进行了研究