钻杆残余应力的磁声发射检测方法研究

Study of magnetic acoustic emission(MAE) testing method on residual stress in drill pipe

阐述了MAE法应力检测机理及MAE检测系统的组成,并通过对磁声发射检测系统中磁化器磁化能力和磁化深度的试验,验证了采用50Hz交流调压器对钻杆进行磁化的可行性;详细分析了拉应力状态下钻杆材料的磁声发射信号特征,提出了采用信号强度相对变化幅度来反映应力改变情况,即通过试验拟合方程来评定应力水平的方法。

The principle of stress testing based on Magnetic Acoustic Emission (MAE) testing method and testing system are briefly described at first. The possibility of magnetizing drill pipe using AC voltage regulator with a frequency of 50 Hz is validated through the experiment on magnetizing ability and magnetizing extent of magnetizers in MAE measuring system. The MAE signal's features under the condition of tensile stress are analyzed in detail and the method of using relative changing amplitude of signal intensity to reflect the stress changing condition, viz. assessing stress level by making experiments and fitting equation is put forward.