柔性机构时变可靠性分析的时变随机响应面法

针对柔性机构极限状态函数的时变、非线性和隐式问题，提出了柔性机构时变可靠性分析的一种新响应面法——时变随机响应面法。首先，将模态综合法与广义混沌多项式方法相结合，建立时变随机响应面，用以描述在随机参数和刚柔耦合影响下，系统响应随时间变化的规律，并得到系统响应的统计特征。与仅用混沌多项式拟合系统响应相比，提高了计算效率。其次，建立系统运动可靠性的时变可靠性模型，给出了时变可靠度的蒙特卡罗计算方法。最后，以两连杆柔性机械臂为例，对方法的有效性进行了验证，结果与蒙特卡罗法相比，具有较高的计算精度。
Abstract：For the limit state analysis of flexible mechanisms with time varying,highly nonlinear and implicit characteristics,the time-varying stochastic response surface method for its time-varying reliability analysis was proposed.The component mode synthesis method was combined with the generalized polynomial chaos,and a time-varying stochastic response surface was established to obtain,the system responses and its statistical characteristics under the random parameters changing over the time.Comparing with the method of polynomial chaos expansion,the computational efficiency is improved.A time-varying reliability model for the mechanism motions was then established,and the Monte Carlo method specially for time-varying reliability analysis was provided.The effectiveness of the method was verified by the analysis of a two-link flexible manipulator.The results show that the method has high computational accuracy compared with the common Monte Carlo method.