This paper presents a robust density-based topology optimization approach for synthesizing pressure-actuated compliant mechanisms. To ensure functionality under manufacturing inaccuracies, the robust or three-field formulation is employed, involving dilated, intermediate and eroded realizations of the design. Darcy's law in conjunction with a conceptualized drainage term is used to model the pressure load as a function of the design vector. The consistent nodal loads are evaluated from the obtained pressure field using the standard finite element method. The objective and load sensitivities are obtained using the adjoint-variable approach. A multi-criteria objective involving both the stiffness and flexibility of the mechanism is employed in the robust formulation, and min-max optimization problems are solved to obtain pressure-actuated inverter, gripper, and contractor compliant mechanisms with different minimum feature sizes. Limitations of the linear elasticity assumptions while designing mechanisms are identified with high pressure loads. Challenges involved in designing finite deformable pressure-actuated compliant mechanisms are presented.

翻译：本文提出一种基于稳健密度法的拓扑优化方法，用于合成压力驱动柔性机构。为确保在制造误差条件下仍保持功能性，采用稳健或三场公式，涉及设计变量的膨胀、中间和侵蚀实现。通过结合概念化排水项的达西定律，将压力载荷建模为设计向量的函数。基于所得压力场，采用标准有限元方法计算一致节点载荷，并利用伴随变量法获取目标函数及载荷灵敏度。在稳健公式中采用包含机构刚度和柔性的多准则目标，通过求解极小极大优化问题，获得了具有不同最小特征尺寸的压力驱动反向器、夹持器和收缩器柔性机构。针对高压力载荷，识别了线性弹性假设在设计机构时的局限性，并提出了设计有限变形压力驱动柔性机构所面临的挑战。