飞机大部件调姿机构磨损预测模型的构建与仿真

Modeling and simulation of wear for alignment mechanism of large aircraft component

针对飞机大部件调姿机构球铰磨损量预测问题,提出一种含间隙的球铰磨损模型.根据球铰的几何结构构建运动学模型;采用含迟滞阻尼系数的连续接触力模型与改进Coulomb摩擦力模型建立球铰的动力学模型;结合Archard方程建立球铰的磨损模型.为了能够获得接触表面的磨损分布情况,将磨损表面离散,借助Hertz接触理论计算接触力的分布,并以离散后的单张曲面为单元分别计算与保存单张曲面磨损量.针对一种四定位器的调姿机构,模拟调姿过程进行仿真计算,结果显示:单个球头表面磨损分布并不均衡,4个球头之间的磨损分布情况类似,但是磨损量存在一定的差异.该磨损模型能够用于调姿机构寿命的预测,并对调姿机构的机械设计提供参考.

To predict the wear extent of spherical joints in alignment mechanism of large aircraft component, a wear model of spherical joint with clearance was proposed. The kinematic model of spherical joint was constructed according to its geometric condition. Continuous contact force model with hysteresis damping coefficient and Coulomb friction law with modification were utilized to develop the dynamic model of spherical joint. The Archard＇s equation was employed to model the wear of spherical joint. To acquire the distribution of wear depth, the surface on the ball and socket was discretized for calculating and storing wear depth. Hertz contact theory was used to obtain the distribution of contact force. Process simulation of alignment mechanism with four positioners was carried out. From the result acquired, it shows that the distribution of wear on the surface is not uniform, and the total wear volumes of each spherical joint are not uniform either. This wear model is also able to be applicable for life prediction and mechanical design of alignment mechanism.