铸钢节点环形对接焊缝的疲劳计算

Application of Hot Spot Stress Method to Fatigue Life Evaluation of Girth Butt Welds of Cast Steel Node

摘要:

给出了采用热点应力法进行铸钢节点环形对接焊缝疲劳寿命估算的全过程.介绍了热点应力幅度的计算方法，即热点应力幅度的计算可根据名义应力和应力集中系数计算，也可采用有限元方法计算.给出了环形对接焊缝热点应力寿命曲线的表示方法和细节分类，列出了各种焊接细节的S—N(应力—寿命)曲线.介绍了线性Miner损伤累积准则.根据热点应力幅度、S—N曲线和线性Miner损伤累积准则，可对铸钢节点环形对接焊缝进行寿命估算.最后，以杭州湾跨海大桥海中平台观光塔铸钢节点为例，说明了波浪载荷下铸钢节点环形对接焊缝的疲劳寿命估算过程

Abstract:

The paper presents the life evaluating process of girth butt welds by hot spot stress method and the calculation methods of hot spot stress range. Hot spot stress range can be calculated by nominal stress range and stress concentrate factor (SCF) or by detailed finite element analysis.The detailed classification methods of S-N curve were explained and the detailed categories of girth butt welds S-N curve were displayed. The weld fatigue life can be evaluated according to hot spot stress range, S-N curve and Miner linear cumulative damage rule. Finally the cast steel nodes in the tour tower structure on the platform of Hangzhou Bay Bridge were introduced to illustrate the process of life prediction of girth butt welds under wave fatigue loading.