摘要
基于寿命—时间分数法 ,考虑蠕变疲劳问题中的分散性 ,建立了蠕变疲劳失效概率的计算模型 ,并采用三种方法对蠕变疲劳失效概率进行计算 ,对各种方法给出的结果及其计算效率进行比较 。
The method is presented for incorporating the scatter in fatigue and creep failure data into existing models for creep fatigue failure prediction to yield the probability of failure for a given loading history. Based on the creep fatigue damage fraction summation rule. The probability of which failure occur after a total creep time t=∑t i and after a total number of fatigue cycles n=∑n j has been calculated. There are three techniques to accomplish this estimation, one based upon the numerical integration of exact relations from probability theory, the second upon the well known Monte Carlo simulation technique and the third upon the second order reliability method (SORM). The results for the example shows that the accuracy of the formulation based on the exact probability integral is limited and Monte Carlo techniques have the marked disadvantage that the estimates for small values of the failure probability are know to be poor too. Of the three techniques outlined here, the SORM appears to be best suited to the solution of the probabilistic creep fatigue problem. This will help engineers make a determination to improve their accuracy and effectiveness in failure probability calculation in structure reliability analysis.
出处
《机械强度》
CAS
CSCD
北大核心
2002年第1期116-119,共4页
Journal of Mechanical Strength