运用焊接结构的S-N曲线获取焊缝裂纹扩展规律的特征参数

Estimate of Characteristic Parameter in Paris's Formula by Using of S-N Curve of Welding Steel-structure

利用疲劳理论中 S-N曲线和线弹性断裂力学中 Paris公式 ,导出了两者之间的换算规律 ,得出了不需通过实验手段估算裂纹扩展规律特征参数的方法 ,并运用该方法得到了结构中常见连接形式的扩展特征参数 ,这些估算值与国外设计规范中推荐使用的参数值相差较小 .结果表明 ,这种估算方法为线弹性断裂力学在港口起重机结构故障诊断中的推广应用 ,开辟了新的途径 .

By means of the S N curve of fatigued theory and the Paris' formula of fracture mechanics,it obtains the conversion rule between them and finds out a method,which can get the characteristic parameter without carrying out an experiment,evaluates the parameters under different kinds of welding connect by using of the method.Comparing with the recommendation of external design rules,the average tolerance is very small.The result points out that the method is of great valuable to the application of fracture mechanics on the steel structure of port machines.