U71Mn50kg·m^(-1)普通碳素钢钢轨疲劳裂纹扩展速率试验研究  

Test and Study of Fatigue Fracture Propagation of U71Mn 50 kg·m^(-1) Ordinary Carbon Steel Rail

作　　者：周小林[1] 向延念[1] 陈秀方[1] 

机构地区：[1]中南大学铁道校区土木建筑学院,湖南长沙410075

出　　处：《中国铁道科学》2004年第3期86-90,共5页China Railway Science

基　　金：怀化铁路总公司科技攻关项目(008)

摘　　要：根据室内对U71Mn50kg·m-1普通碳素钢钢轨按三点弯曲标准进行的试验,测定该钢轨的疲劳裂纹扩展速率,即裂纹扩展深度a及其对应的循环次数N值。利用中值法求得裂纹扩展深度对循环次数的微分值。根据断裂理论求得相应的裂纹前沿应力强度因子幅度ΔK。根据Paris公式,对以上两值取自然对数进行线性回归分析,确定该公式中U71Mn50kg·m-1普通碳素钢钢轨疲劳裂纹扩展速率的两个材料常数C为3 8771×10-12,m为3 6343。Based on the test of the U71Mn 50 kg·m^(-1) ordinary carbon steel rails on the basis of the in-lab three-point curve standard, the paper defines the rail fatigue fracture propagation rate, i.e. the value of the fracture propagation depth a and the corresponding number of cycles N. The median method is used to get the differential value of the fracture propagation depth against the number of cycles. According to the fracture theory, the corresponding fracture front stress intensity factor amplitude ΔK is obtained. According to Paris formula,the natural logarithm of the above two values is obtained and analyzed with linear regression method. It is determined that the two material constant values C and m of the fatigue fracture propagation rate of the U71Mn 50 kg·m^(-1) ordinary carbon steel rail are 3.877 1×10^(-12) and 3.634 3 respectively.

关 键 词：钢轨 疲劳裂纹扩展速率 强度因子 试验分析 

分 类 号：U213.42[交通运输工程—道路与铁道工程]