变密度法在挖掘机动臂轻量化设计中的分析与应用

Analysis and Application on Variable Density Method in the Process of the Excavator Boom Lightweight Design

基于多体动力学的基本原理,建立了挖掘机工作装置的刚柔耦合模型。动臂拓扑优化设计采用变密度法,以动臂重量最小化为目标函数,以动臂各单元的相对密度为设计变量,强度和刚度为约束条件。根据计算后得到的相对密度云图对动臂进行轻量化设计,优化后的动臂减重最高可达30.8%。对比分析了拓扑优化设计前后动臂在规定时间内动态应力应变曲线变化趋势,应力应变曲线显示优化后动臂的应力和位移均有小幅增大,但均在许用值范围内,结果表明该优化方法是可行的。

Based on the principle of multi-body dynamics, the rigid-flexible coupling model of excavator working device is established. Topology optimization design on boom is performed by the method of variable density design, with the boom weight minimization as the objective function, strength and stiffness as the constraint conditions.Lightweight design is implemented in the boom based on the relative density contours calculated, so the weight reduction of the boom optimized can be up to 30.8%. Within the specified time, the trends on dynamic stress-strain curve between the optimized boom and the original boom are compared and analyzed, the stress-strain curve indicates that stresses and displacements of the optimized boom are slightly increased, but they are within the allowable range of values, the results show that the optimization method is feasible.