超声疲劳裂纹扩展与摩擦生热研究

发布时间：2018-06-17 15:13

  本文选题：超声疲劳 + 超高周疲劳　； 参考：《机械工程学报》2016年04期

【摘要】：在高频循环载荷作用下,材料疲劳裂纹的萌生与扩展过程伴随着明显的温度变化,该温度变化反映材料内部结构的损伤特征。通过20 kHz的超声疲劳试验,研究一种碳锰钢在超高周疲劳加载条件下的内部疲劳裂纹萌生与扩展过程中温度的演化过程。通过对该材料在疲劳损伤过程中,内部裂纹间的摩擦生热机理分析,从微观角度出发,结合分形理论,建立内部裂纹微观结构的摩擦模型,数值模拟超声疲劳过程中材料内部疲劳裂纹面间的摩擦生热情况,并定量地计算该过程中由裂纹间摩擦所导致的温度上升,将模拟结果与试验结果进行比较。探究高频疲劳载荷下微裂纹扩展与摩擦生热的关系,并结合超高周疲劳裂纹扩展公式,建立超声疲劳过程中的裂纹扩展与裂纹面温度演化关系的模型。
[Abstract]:Under high frequency cyclic loading, the initiation and propagation of fatigue cracks in the materials are accompanied by obvious temperature changes, which reflect the damage characteristics of the internal structures of the materials. The temperature evolution of internal fatigue crack initiation and propagation of a carbon-manganese steel under ultra-high cycle fatigue loading was studied by ultrasonic fatigue test at 20 kHz. Based on the analysis of friction heat generation mechanism between internal cracks in the process of fatigue damage, the friction model of internal crack microstructure is established from the microscopic point of view and the fractal theory. The friction heat generation between the fatigue crack surfaces in the material was simulated numerically, and the temperature rise caused by the friction between the cracks in the process was calculated quantitatively. The simulation results were compared with the experimental results. The relationship between microcrack growth and friction heat generation under high frequency fatigue loading is studied. A model of the relationship between crack growth and crack surface temperature evolution during ultrasonic fatigue is established by combining the ultra-high cycle fatigue crack propagation formula.
【作者单位】： 西北工业大学机电学院;
【基金】：自然科学基础研究计划资助项目(2015JM1007)
【分类号】：TG115.57
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本文编号：2031486