Elevation of fatigue behavior of T-type welded joint in the small-sized single pass boiler
Small-sized single pass boilers are usually designed based on the construction code for small-sized boilers in Japan. Design methods in this construction code and other country codes have not been defined clarity, although most of small-sized boilers header are constructed by two concentric circular shells and cover plates. Therefore, Finite Element Analysis (FEA) and the measurement by strain gauges are mainly used in strength design of these boilers. In this study, T type welded joint of SS400 was adopted for header of small-sized single pass boilers. Fatigue test was carried out at room temperature in air. Fatigue strength was greater for base metal specimen than that of welding specimen. The stress concentration at the toe was evaluated by the FEA. S- N curves for different toe curvature radius were rewritten by using maximum elastic stress. The crack initiation occurred from the welding defect in the vicinity of the toe. These cracks coalesced together at crack length of 10mm. K<,in> value for the welding defect could be calculated and was 1.78MPa·m<1/2>
Welded joint S-N curve Boiler Fatigue Strength Welding defect
Nu Yan H. Yamakawa R. Murakami D. Yonekura
Deptartment of Mechanical Engineering, The University of Tokushima, Tokushima 770-8506, Japan Miura Co., Ltd. Matsuyama-shi 799-2696, Japan
国际会议
国际断裂力学2007年会(Fracture Mechanics and Applications 2007)
长沙
英文
89-92
2007-11-01（万方平台首次上网日期，不代表论文的发表时间）