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

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.

Key words:cast steel node; girth butt weld; fatigue; hot spot stress