基于某运煤专线测试的车钩载荷—时间历程研究万吨重载货车车钩试验载荷谱的编制方法。将测试的重载货车车钩载荷—时间历程划分为装煤、重车运行、卸煤和空车运行4个工况,应用Ncode数据处理软件将车钩载荷分解为趋势载荷和小幅值循环载荷两部分,采用变均值法和雨流计数法相结合的方法分别编制了趋势载荷谱和测试载荷谱。基于车钩趋势载荷编制的载荷谱与测试载荷谱虽然在高载荷区比较一致,但在低载荷区相差较大,因此,根据疲劳损伤等效原则,将小幅值循环载荷造成的车钩损伤叠加于趋势载荷造成的车钩损伤,得到力值放大的等效趋势载荷,然后采用等效趋势载荷编制不同工况下车钩疲劳试验脉动拉伸载荷谱和脉动压缩载荷谱。该编制方法可以大幅度减少车钩疲劳试验的次数,提高试验效率。
The compilation method for the test load spectrum of coupler on 10 000 t heavy haul freight car was studied on the basis of load-time history obtained from the tested coupler on a special line for coal transportation. The load-time history of the tested heavy haul freight car coupler was divided into four working conditions, namely, coal loading, loaded car operation, coal unloading and empty car operation. The coupler load was decomposed into two parts of trend load and small value load by Ncode data processing software. The trend load spectrum and measured load spectrum was compiled respectively by combining variable mean method and rain flow counting method. Although the load spectrum and meas- ured load spectrum based on the trend load of the coupler were consistent in high load region, there was a big difference in low load region. Therefore, the coupler damage caused by small amplitude cyclic load was cumulated to the damage caused by trend load according to the fatigue damage equivalence principle, and the equivalent load enlarged hy trend load was obtained. Then, the tensile load spectrum and compressive load spectrum for testing were established under different operating conditions based on the equivalent trend load. The compilation method for fatigue test load spectrum can greatly reduce the number of fatigue test of the coupler and improve the test efficiency.