间隙球铰接触区域快速检索及磨损问题高效求解方法

Efficient Contact Position Detection and Wear Prediction for Spherical Joint in Spatial Multibody System

针对多体系统中间隙球铰接触磨损计算效率低的问题,提出一种基于查找表的间隙球铰接触区域检索和磨损预测方法。将球铰接触界面离散化,并将离散点的几何位置、运动参数及磨损信息存储为查找表;任一瞬时球铰内接触探测可通过检索查找表的方式来实现,避免逐点计算空间距离的复杂性;采用修正的赫兹接触模型求解微间隙球面共形接触问题,相对有限元方法有较高计算效率,并可获得较精确的应力分布;在统一计算模型下实现多体力学与接触磨损分析的有效集成。含间隙球铰的空间连杆机构动力学与磨损耦合分析结果表明:曲柄105转磨损周期内,球铰磨损区域基本位于纬度-30°~80°之间,在经度方向的磨损区域随时间而逐渐扩展;总计算耗时为83min,较有限元接触磨损分析具有更高的计算效率。

A new contact analysis approach based on lookup table is proposed to deal with the problem of low calculation efficiency involved in wear prediction for clearance ball joint in multibody system considering the interaction between wear and mechanical dynamics.The proposed method utilizes lookup table to store the geometric position,kinematical parameters and wear depth of discrete points on the surface of the ball joint after the contact surface is discretized as regular and representative points.By checking the table,required information can be extracted to determine contact location instead of calculating the spatial distance of contact points.Accurate contact stress distribution for conformal contact with micro clearance is gained using modified Hertz model with less computational cost than finite element method.Thus, multi-body dynamics and contact wear can be integrated into the unified model efficiently.A spatial linkage mechanism with ball joints containing clearance is taken as example to verify the proposed method.Numerical results show that the wear occurs dominantly in the latitude interval of-30°~80°the wear region and the wear region expands greatly along longitude direction after 105 revolutions of crank,the computation time is only 83 min,and higher calculation efficiency is obtained compared with finite element analysis.