Fatigue strength estimation of butt-welded joints between cast-steel and hot-rolled-steel plates: Fid-Bau Portal

Fatigue strength estimation of butt-welded joints between cast-steel and hot-rolled-steel plates

Peng, Yang / Zhu, Xiaoli

Abstract Fatigue strength of tubular structures made of cast steel nodes is generally governed by the fatigue strength of girth butt-weld between stubs in the cast steel node and hot rolled tubes. Previous experiments found that fatigue cracks initiated at the weld root of the girth butt-weld and propagated in the weld metal or heat affected zone of the weld. The present paper investigated the fatigue strength of the weld root crack of the girth butt-welds by using linear elastic fracture mechanics (LEFM) method. Different initial crack sizes, initial crack shapes and materials properties relating to crack propagation were studied based on literature review. Comparisons between the predicted results and Puthli's experimental results indicated that the LFEM model was valid. Size effect including thickness effect and eccentricity effect of unequal thickness was discussed based on this LFEM model. The fatigue strength of the girth butt-weld decreases as the plate thickness increases. But the increase of the eccentricity of the thickness may not always reduce the fatigue strength of the girth butt-weld.

Highlights • Backing strips are the most effective method to guarantee the quality of weld root in butt-weld. • Fatigue strength of the butt-weld decreases as the plate thickness increases. • Increase of the eccentricity of the thickness may not always reduce the fatigue strength of the butt-weld.