In this work, a density-based method is applied for synthesizing compliant mechanisms using topology optimization. This kind of mechanisms uses the elastic strain as the basis for kinematic actuation and it is widely used in precision mechanical devices, in biomedical engineering, and recently in MicroElectroMechanical Systems (MEMS). Geometrical and material (compressible hyperelasticity) nonlinearities are taken into account to obtain mechanisms near real-world applications. A strength criterion for the optimization problem is applied, to design compliant mechanisms that fulfill the desired kinematic tasks while complying with a stress threshold. The addition of a stress constraint to the formulation also aims to alleviate the appearance of hinges in the optimized design. Employing benchmark examples, we investigate the influence of a nonlinear formulation with a stress constraint in the final designs. It is shown that material nonlinearity plays an important role for stress constraint problems. The use of a projection scheme helps to obtain optimized topologies with a high level of discreteness. The Method of Moving Asymptotes (MMA) is applied for design variables updating and the required derivatives are calculated analytically by the adjoint method.

在这项工作中，基于密度的方法适用于使用拓扑优化来合成兼容机制。这种机制以弹性应变为运动学驱动的基础，并广泛用于精密机械设备，生物医学工程以及最近的微机电系统（MEMS）中。考虑了几何和材料（可压缩的超弹性）非线性，以获得接近实际应用的机制。将优化问题的强度标准应用于设计可满足所需运动学任务并同时符合应力阈值的兼容机制。在配方中增加应力限制的目的还在于减轻优化设计中铰链的外观。利用基准示例，我们研究了在最终设计中具有应力约束的非线性公式的影响。结果表明，材料非线性在应力约束问题中起着重要作用。投影方案的使用有助于获得高度离散的优化拓扑。应用移动渐近线方法（MMA）进行设计变量更新，并通过伴随方法解析计算所需的导数。