基于两步七点拟合法ADB610钢概率疲劳裂纹扩展研究

摘要

Twice seven data incremental polynomial fitting method (short for twice seven data fitting) was introduced which can be used to calculate fatigue crack propagation rate of each sample in a series of same crack length. Then fatigue crack propagation rate (P - a - da/dN) and the equations of fatigue crack propagation rate based on Paris (P - da/dN -ΔK) in different probability can be obtained. And twice seven data fitting method was adopted to calculate crack propagation rate of each 7 CT samples of ADB610 steel in a series of same crack length. It was calculated for the crack propagation rate and the e-quation of crack propagation rate based on Paris of ADB610 steel with probability in 50% ,90% ,95% , 99% and 99.9%.%介绍了两步七点递增多项式拟合方法(简称两步七点拟合法)计算一系列相同裂纹长度下成组多个试样的裂纹扩展速率,然后计算一系列相同裂纹长度在不同存活率下的裂纹扩展速率P-a -da/dN和基于Paris公式的裂纹扩展速率表达式P-da/dN-△K.并采用两步七点拟合法计算了广泛应用于压力容器的ADB610钢7个CT试样在一系列相同裂纹长度下的裂纹扩展速率,以及计算了ADB610钢在存活率分别为50％,90％,95％,99％和99.9％的裂纹扩展速率和基于Paris公式的裂纹扩展速率表达式,有助于ADB610钢抗疲劳断裂可靠性的分析研究.