基于交流电位法的疲劳裂纹长度测量方法与装置

Measurement Method and Equipment of Fatigue Crack Length Based on Alternating Potential Method

阐述了交流电位法测量疲劳裂纹长度的原理和方法,并研制了一套基于交流电位法的疲劳裂纹长度测量装置。该测量装置以LabVIEW为平台,构成了虚拟仪器系统,对数据进行采集、分析和处理,实现了可视化操作、自动测量、曲线显示和数据保存等功能。利用该设备测试了Ti1023钛合金和7055铝合金两种材料试样的疲劳裂纹扩展情况。试验结果表明:该设备的分辨率小于1μm,利用该装置可以连续测试电压随疲劳周次的变化曲线,并根据标定关系实时转换成裂纹长度随疲劳周次的变化曲线。

The principles of measuring the fatigue crack length based on alternating potential method were interpreted and an equipment of measuring the fatigue crack length based on alternating potential method was developed.This equipment based on LabVIEW is a virtual instrument system which can acquire,analyze and process data and has functions of visualization operation,automatic measurement,curves displaying and data storage.The fatigue crack length of Ti1023 titanium alloy and Al7055 aluminum alloy was measured by this equipment.The results show that the resolution of this equipment is less than 1μm,and the equipment can measure the relationship between the measuring voltage and fatigue cycles which can be translated into the relationship between fatigue crack length and fatigue cycles based on the calibration.