随机裂纹叶片抗共振可靠度及概率敏感性分析

Antiresonance Reliability and Probabilistic Sensitivity Analysis for Random Cracked Blade

考虑叶片裂纹参数的随机性,研究裂纹叶片的抗共振可靠性和概率敏感性。首先考虑裂纹位置、深度和转速为随机变量,建立裂纹叶片的参数化有限元模型,并应用中心复合采样方法进行采样;然后采用元模型技术建立了叶片频率的二次线性回归近似模型,并采用3个误差指标评价模型的精度。最后用此近似模型代替有限元模型,用蒙特卡罗模拟方法研究了裂纹叶片在不同转速时频率的概率敏感性和抗共振可靠性。结果表明裂纹叶片频率对转速的概率敏感性很大,对裂纹深度的概率敏感性较大。

The antiresonance reliability and probabilistic sensitivity of cracked blade with random parameters of crack were studied.The parametric finite element model of the cracked blade with random location,depth of crack and rotating speed was built.The sample points were obtained based on central composite design.A quadratic polynomial linear regressive model was chosen as metamodel to establish the surrogate of the finite element model,and the accuracy of the surrogate model was evaluated through three performance metrics.The finite element model replaced by the approximate model and the Monte Carlo simulation（MCS） was used to study the probabilistic sensitivity and reliability of the cracked blade under different rotating speed.The results show that the probabilistic sensitivities of rotating speed and depth of the crack are larger than those of position of crack.