基于应变模态分析的长输油气管线损伤检测仿真研究

基于应变模态方法，运用有限元分析软件ANSYS对石油工业中的压力管道损伤识别进行了初步的研究。ANSYS的模态分析可以求得结构在损伤前后的位移模态，将其转换为对应阶数的应变模态，并对比应变模态损伤前后的变化，作出应变模态差值曲线以此来判断损伤的存在和位置以及损伤程度。计算结果表明：利用应变模态差值曲线能比较准确地识别出管道结构模型的损伤存在和损伤位置，并依此定性地识别出管道结构模型的损伤程度。采用此方法进行管道结构进行损伤识别比传统的损伤检测方法更加准确、方便。

Identifying the damage of pipeline model based on the vibration model method

Based on the method of strain mode, the damage identification of a beam model of pipeline structures is studied via the finite element analysis software ANSYS. The displacement model responding the normal and damaged cases are obtained by the model analysis of the ANSYS. The change of the strain model is studied in order to estimate the existence and location even the extent of the damage. The result show that the damage existence and the position of the pipeline model can be accurately identified by the difference curve of the strain mode; and the laws that the peak values of strain mode increase with the element damage degree of the pipeline beam model can be used to detect the damage degree of the pipeline model. The strain model analysis method is more accuracy and continent compared the other traditional methods in the damage detections of the engineering structures.