汽轮机转子的多变量随机动态响应及可靠性分析

Stochastic Multivariable Dynamic Response and Reliability Analysis of the Turbine Rotor

为了满足汽轮机转子的高可靠性设计要求,利用ANSYS的APDL语言二次开发功能,考虑汽轮机转子材料物性参数和载荷参数等多随机变量同时作用的情况,将积分随机有限元法嵌入到ANSYS软件当中,编制汽轮机转子的多变量随机应力应变均值及其各阶中心矩的计算程序,通过与Monte-Carlo模拟方法相对比,验证了该方法的正确性。根据计算得出的汽轮机转子最大应变的各阶中心矩,通过Gram-Charlier级数拟合得到汽轮机转子应变随机响应的概率密度函数,并依据可靠度计算公式计算得出转子的可靠度。同样与直接Monte-Carlo模拟方法相比较,计算结果表明,两者相对误差较小,验证了采用级数拟合方法的合理性。

In order to improve the reliability of the turbine rotor design, used APDL which was the secondary development function of ANSYS and considered the random character of the material parameters and load parameters of the turbine rotor, the integral stochastic finite element method was embedded into ANSYS, and the calculation program module was generated which could calculate the different order central moments, and the mean of the stress and the strain of the turbine rotor, and then the Monte-Carlo simulation results verify its efficiency and quick. Following the different order central moments of the maximum strain of the turbine rotor, the probability density function of the strain was fitted by the Gram-Charlier series, and the reliability of the rotor was Calculated through the reliability computing formula. Against the Monte-Carlo method, the results show that the series fitted exists less relative error with the Monte-Carlo method and is viable.