超声波对比法测试金属塑性变形前后残余应力的变化

The Experimental Study on Residual Stress Change by Ultrasonic Comparing Testing of Plastic Deformation of Metals

采用超声检测方法,通过声弹性理论可计算出残余应力的数值。但是由于实际声速很难准确测量,使得该方法在实践中的可操作性受到了限制。介绍了声速和残余应力间关系,用对比实验的方法来分析声速变化和残余应力变化之间的关系。实验表明,试件受拉伸至塑性变形,内部所受残余拉应力增大,同一试件的同一位置超声波测得的回波波峰处声程减小。若不涉及残余应力具体值,只关心应力变化的情况下,可以通过超声波对比法判断残余应力的变化。该方法具有实用性和可操作性。

Using ultrasonic testing,residual stress values can be derived from sound elastic theory,but its real feasibility is restricted because practical sonic speed is difficult to accurately measure.The comparing experimental method was adopted to analyze the relationship of sonic speed and residual stress change based on the determined relationship.The result indicated that when the inner residual stress was increasing,the sound distance was reducing in the same disposition of echo wave peak.According to the reg...