Fatigue S-N Relations of the Cast Steel for Chinese Railway Rolling Wagon Bogie Frames
Fatigue S-N relations are investigated experimentally on the grade B cast steel for Chinese railway freight car bogie frames. Group test method was employed. Results reveal that the fatigue cracks were initiated from the material cast shrinking cavities with hot ties. Distinct fatigue striations, river-like flowers, and second cracks appeared on the fracture surface in perpendicular to the fatigue crack path. Lots of dimples in the transient fracture district indicate that present material is ductile. Considering both the scattered S-N relations and no fatigue limits under variable loads, the S-N relations are measured probabilistically in terms of continuous declined probabilistic S-N curves including super-long life regime (SLLR) of >107 cycles. Affordable novel approach, i.e. concurrent probability extrapolation method, was applied. The test S-N data in mid-long life regime (MLLR) and conventional fatigue limits are used. The curves are established by extrapolating the conventional S-N curves crossing the fatigue limits, in a concurrent probability manner, into the SLLR. Appropriate measurements have been given for the test data of the present material.
Cast steel Fatigue S-N relation Railway Rolling wagon Bogie frame
Lei Chen YongXiang Zhao Yang Bing
Institute of Engineering Reliability and Safety, Traction power State key Laboratory, Southwest Jiaotong University, Chengdu 610031, China
国际会议
沈阳
英文
181-185
2010-07-28（万方平台首次上网日期，不代表论文的发表时间）