压力管道腐蚀灾变检测的应变敏度比法

DETECTION OF THE CORROSION DAMAGE IN PRESSURE PIPELINE USING STRAIN SENSITIVITY RATIO MEHOD

基于结构振动模态测试理论和有限元方法提出了压力管道腐蚀检测的应变敏度比法。首先,通过位移模态及应变模态建立了腐蚀管道的定位检测判据。其次,制备不同缺陷的管道,应用应变敏度比法检测判断缺陷位置,结果表明,检测位置与实际损伤位置完全一致。最后,通过数值算例证实用前1阶模态分量数据检测的结果与实际缺陷基本一致。通过实测和数值算例证明了只测试损伤及未损伤结构的低阶模态参量,便可进行有效的检测,而低阶参量是相对简单易测,从而使该方法应用于工程实际更显便利。

Based on structural modal test theory and finite element method, strain sensitivity ratio method of detection for the corrosion damage in pressure pipeline is presented. First, the damage-locatization criterions to locate damage through displacement mode and strain mode are established. Secondly, all kinds of pipelines with different damages are prepared and detected by this damage detection method. The result shows that the damage location predicted by this method is the same as the real one. Finally, the numerical example verifies that the result using the first one-order modal shape is basically consistent with the real damage. These results prove that strain sensitivity ratio method locating damage in pressure pipe only require measurements of few of the pipeline＇s natural frequencies and the lower displacement mode under both the undamaged and damaged states. And this method is shown to provide good predictions of damage location. Since the lower-order modal shape can be measured easily, this method is convenient to apply in engineering practice.