造船液压机压头锁紧碟簧疲劳寿命稳健优化设计

Fatigue life robust design of clamping disc springs for a shipbuilding hydraulic press head

碟簧(碟形弹簧)的材料特性、几何特性、载荷等因素发生较小的波动,就会导致碟簧特性的变化,使其实际使用寿命与设计寿命出现较大偏差.针对碟形弹簧的疲劳寿命受不确定性因素影响而波动较大的问题,采用分析性稳健设计方法,对移动回转压头造船液压机压头锁紧碟簧的疲劳寿命与不确定性因素的关系进行了研究;以碟簧疲劳寿命的波动方差最小为目标函数,疲劳寿命均值等于预期寿命为等式约束,碟簧组轴向力大于允许值为不等式约束,建立碟簧疲劳寿命稳健优化模型,并获得了稳健设计解.稳健优化后的结果与优化前相比,在满足性能约束的条件下使不确定性因素的变化对碟簧疲劳寿命的影响降到最低,碟簧的疲劳寿命稳定在目标值附近,提高了设计的经济性和可靠性.

Performance characteristics of disc spring will change when there is a little variation of its structure and material parameters,causing a large deviation of its physical life from the design life. Based on the issue that fatigue life of disc springs is affected by uncertainty factors, analytical robust design method was adopted to study the relation between fatigue life and uncertainty factors of hydraulic press head clamping device disc spring;fatigue life robust optimization model of disc spring was established, with minimizing the variance of disc spring fatigue life as objective function,the mean value of disc spring fatigue life equal to expected value as equality constraint, axial force of disc spring group larger than allowed value as inequality constraint;then robust op- timization was carried out. Comparing with the design results before optimization, the results after optimization reduce the affection of uncertain factors to disc spring fatigue life as low as possible under performance constraints, and disc spring fatigue life stabilizes nearby the expected value, which improves the efficiency and reliability of the design.