This paper presents a topology optimization approach to design 2D contact-aided compliant mechanisms (CCMs) that can trace the desired output paths with more than one kink while experiencing self and/or external contacts. Such CCMs can be used as mechanical compliant switches. Hexagonal elements are used to parameterize the design domain. Negative circular masks are employed to remove material beneath them and generate rigid contact surfaces. Each mask is assigned five design variables. The first three decide the location and radius of the mask, whereas the last two determine the presence of the contact surface and its radius. To ensure continuity in contacting surfaces' normal, we employ a boundary smoothing scheme. The augmented Lagrange multiplier method is employed to incorporate self and mutual contact. An objective is formulated using the Fourier shape descriptors with the permitted resource constraint. The hill-climber optimization technique is utilized to update the design variables. An in-house code is developed for the entire process. To demonstrate the method's efficacy, a CCM is optimized with a two-kink path. The desired and obtained paths are compared.

翻译：本文提出了一种拓扑优化方法，用于设计能够追踪具有多个拐点的期望输出路径的二维接触辅助柔顺机构，该机构在工作过程中会发生自接触和/或外部接触。此类接触辅助柔顺机构可用作机械柔顺开关。采用六边形单元对设计域进行参数化。使用负圆形掩模移除其下方材料以生成刚性接触表面。每个掩模被分配五个设计变量：前三个决定掩模的位置和半径，后两个则确定接触表面的存在性及其半径。为确保接触表面法向的连续性，我们采用了边界平滑方案。利用增广拉格朗日乘子法来处理自接触与相互接触。基于傅里叶形状描述符并考虑允许的资源约束构建目标函数。采用爬山优化技术更新设计变量。为此开发了内部代码以完成整个流程。为验证方法的有效性，对一个具有双拐点路径的接触辅助柔顺机构进行了优化设计，并对期望路径与所得路径进行了对比分析。