高频荷载作用下无砟轨道裂纹内动水压特性试验

Characteristic Tests of Internal Dynamic Water Pressures of Non-ballasted Track Cracks under High-frequency Loading

研究无砟轨道以裂纹为主要形式的伤损问题时,水对裂纹扩展有重要影响。为明确裂纹内部水压力的分布规律及压力大小的影响因素,浇筑带水平裂纹的无砟轨道试件,考虑万能伺服液压机疲劳加载与水耦合作用条件,采用高灵敏度传感器测量水压,试验研究了裂纹不同位置压力变化规律和加载频率、荷载幅值对水压力的影响。试验表明,裂纹内部水压力随荷载幅值而正负交替变化,随着裂纹深度的增加,水压力增大;当加载幅值不变时,水压力随加载频率增加而增大;当加载频率不变时,水压力随着荷载幅值的增加而增大,荷载幅值和频率的影响可拟合为一个多项式关系。

When the crack is studied as a maj or damage forms of a non-ballasted track,water has an important effect on the cracks propagation.In order to clarify the distribution law of water pressures inside cracks and the factors influencing such water paressures,non-ballasted track specimens with horizontal cracks.Fatigue loads were applied by the universal servo-hydraulic machine and were coupled with water,the high-sensitivity sensor was used to measure the water pressures.The changing law of the water pressrues at different locations inside the cracks,and the influence of loading frequencies and load amplitudes on the water pressures were studied. The test show as follows：The water pressrues inside the cracks exhibit alternating positive and negative changes with changing of load amplitudes,and increases with increasing of crack depths;when the load amplitude is kept constant,the water pressures increase with increasing of load amplitudes;the load amplitude and loading frequency can be fitted into a polynomial relationship.