随机动载荷作用下刨煤机刨链疲劳寿命预测

Prediction of fatigue life of coal plow chain under stochastic dynamic load

通过建立的刨煤机动力学模型,采用雨流法、线性Miner疲劳累积损伤模型,对刨链疲劳寿命进行预测。通过仿真计算,得到不同随机刨削阻力、不同刨链预紧力以及不同链轮齿数作用下的刨链疲劳寿命。结果表明:刨削阻力均值增加,疲劳寿命降低;增大刨链预紧力或增加链轮齿数均可提高刨链疲劳寿命;随机煤壁作用力和刨链预紧力对刨链的疲劳寿命影响较大,链轮多边形效应影响较小。通过刨链张力测试实验,分析在不同刨削深度情况下张力实验数据,得到刨链疲劳累积损伤规律与通过仿真得到的规律一致。

Through dynamic model of the coal plow,rain flow counting method and linear Miner fatigue cumulative damage model were used to predict fatigue life of plow chain.Through simulation,fatigue life of plow chain can be obtained under different stochastic cutting resistances,different pretension forces of plow chain and different number of sprocket teeth.The simulation results show that increasing of mean value of cutting resistance make fatigue life decrease,improvement of pretension force of plow chain and number of sprocket teeth make fatigue life increase,and stochastic forces of coal and pretension force of plow chain have obvious effects on fatigue life of plow chain,but influence of sprocket polygon effect is less.Test data of chain tension were analyzed under different cutting depths through the test of plow chain tension.And fatigue cumulative damage change of the plow chain accords with damage change of plow chain by simulating dynamic model.