【摘要】 通过对基于多因素修正的剩余寿命预测方法中的应力集中因子进行推导,提出了一种基于多因素修正的结构件裂纹扩展预测方法,从而实现了结构因素、应力比、加载方式、表面质量系数与构件裂纹扩展之间的量化关系表达.将所提方法应用于具体的实例构件的裂纹扩展预测中,并定量分析了所提出的各具体修正因素对实例构件裂纹扩展预测结果的影响.同时,运用基于Weibull分布概率密度方程的概率方法对修正后方法预测结果的精度进行评价,通过概率密度方程对实际预测结果所对应的概率密度值进行了求解.结果表明,该方法的预测结果比断裂力学的预测结果更精确,更接近试验结果.更多还原

【Abstract】 By deriving the stress concentration factor of the estimation approach for residual fatigue life,an estimation approach for structure crack propagation based on multiple factors correction is proposed.Then,the quantitative expression among the structure factor,stress ratio,loading type,the manufacture processing factor and the crack propagation is achieved.The proposed approach is implemented in a case study for an instance structure,and the influences of correction factors on the crack propagation are analyzed.Meanwhile,the probabilistic method based on Weibull distribution probability density function is selected to evaluate the precision of the corrected estimation approach,and the probability density of results is calculated by the probability density function.It is shown that the results estimated by the corrected approach is more precise than those estimated by the fracture mechanics,and they are closer to the test data.更多还原