基于模糊综合评判的机床床身多目标优化设计

Multi-objective optimization design for machine tool body based on fuzzy comprehensive evaluation

为了提高机床床身的抗振性并减轻质量,对床身进行了多目标优化设计。在CAD软件SolidWorks中建立了某机床床身的几何模型,然后将其导入ANSYS软件中进行模态分析。以床身的质量和前三阶固有频率为目标函数,以筋板厚度为设计变量,建立了多目标优化数学模型,结合粒子群优化算法进行求解后得到四组非劣解。利用模糊综合评判法从非劣解集中挑选出了一组最佳解,将此优化设计方案用于床身的实际制造,从而使床身在质量下降3.18%的同时,前三阶固有频率分别提高7.03%、9.64%、10.73%。研究表明,粒子群算法和模糊综合评判法具有较高的工程实用性。

The multi-objective optimization design was carried out in order to improve a machine tool body＇s vibration resistance and reduce its mass. The geometry model of a machine tool body was established in the CAD software SolidWorks, and the modal analysis was conducted after the model was imported into the ANSYS software. Then a multi-objective optimization mathematical model of the machine tool body was built, with the body＇ s mass and the first three natural frequencies being the objective functions, and the thickness of rib plate being the design variable. By using the particle swarm optimization to solve the mathematical model, four group non-inferior solutions were obtained. The best solution was selected from the non-inferior solution set through fuzzy comprehensive evaluation. Using the optimization design proposal to manufacture the machine tool body brought the good effect that the mass decreases 3.18% and the first three natural frequencies increase 7.03%, 9.64%, 10.73% respectively. The study shows that the particle swarm optimization and the fuzzy comprehensive evaluation have high engineering practicability.