矿用车车架结构的静动态多目标拓扑优化

Static / Dynamic Multi-objective Topology Optimization of the Frame Structure in a Mining Truck

为了实现行驶工况极为恶劣的矿用车的车架结构的静动态多目标拓扑优化,以静态多工况下刚度和动态多个低阶频率为目标函数,提出了一种车架多目标拓扑优化方法。基于变密度法建立车架结构拓扑优化模型,采用折衷规划法确定多工况刚度拓扑优化目标函数,以平均频率法确定振动频率目标函数,并利用层次分析法选定子目标权重。优化结果显示车架的刚度和固有频率均有提高。对优化后的新车架和原车架进行疲劳寿命的对比分析,结果表明:采用多目标拓扑优化后车架的疲劳寿命明显提高,改善了车架的使用性能。

To achieve static / dynamic multi-objective topology optimization for the frame structure of a mining truck in extreme adverse working conditions, a multi-objective topology optimization scheme for vehicle frame is proposed with static stiffness for multi-conditions and multi-low-order-frequencies as objective functions. A topolo- gy optimization model for frame structure is built based on variable density method, and the objective functions for multi-conditions stiffness topology optimization and vibration frequency optimization are determined by using compro- mise programming approach and mean frequency method respectively with their weighting factors selected by analytic hierarchy process. Topology optimization is performed, leading to the increases in both stiffness and low-order natu- ral frequencies of frame. A comparative analysis on fatigue life is performed on both new frame after optimization and original one and the results show that after multi-objective topology optimization the fatigue life of frame is apparently increased with its operation performance improved.