HTS-A钢对接接头双轴低周疲劳萌生寿命研究

摘要

Both longitudinal bending cyclic load and vertical compressing cyclic load are applied on welding butt joint. There are two parts of works for estimating crack-initiation life of the joint:analyzing stress and strain at the weld toe and choosing a suitable estimation model based on strain. Modified multi-axial Neuber’s law is applied in the analysis of the state of stress and strain at the weld toe. Crack-initiation life at welding butt joint is calculated with four different estimation models under different conditions of load ratio. Then the result is compared with the test.%焊接接头在垂向受压和纵向受弯组合循环应力状态下的低周裂纹萌生寿命估算工作分为两部分：焊趾处（循环）应力应变状态分析和应变寿命估算模型选择。用疲劳缺口系数代替应力集中系数这样的修正多轴Neuber法来分析焊趾处的应力应变状态。用四种应变-寿命估算模型计算了平板对接接头在不同载荷比下的疲劳萌生寿命，并与试验进行了对比分析。