Topology optimization design of excavator working device based on equivalent static loads

To address the dual requirements of dynamic topology optimization and static strength in the design of excavator working devices, this paper proposes a dynamic topology optimization method based on equivalent static loads. First, a rigid-flexible coupling dynamic model of the working device is constructed under combined excavation conditions to analyze the dynamic response of the arm in terms of stress and deformation. Then, local element stress constraints are converted into global constraints using the P-norm method. A topology optimization model is established with the minimization of the arm's maximum flexibility as the objective function, constrained by the P-norm stress and volume fraction. Finally, dynamic topology optimization of the arm is performed using the equivalent static loads method, and the topological structure of the arm is redesigned with consideration for manufacturability. Finite element simulation results demonstrate that the proposed method achieves a 24.63% reduction in the mass of the arm, while the maximum stress increases by only 5.26% and remains below the material's allowable limit, thereby fulfilling the design requirements.