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针对在超声红外热像技术中被测对象缺陷区域生热机理研究不深入的问题,以含裂纹平板试件为研究对象,采用ANSYS/LS-DYNA对含裂纹的平板试件进行热固耦合建模,研究了高频振动激励下平板振动信号及频谱,分析了裂纹摩擦生热及塑变生热的特点。仿真及试验结果表明:热固耦合分析用于裂纹生热问题可行;高频振动下裂纹生热形式主要有摩擦生热和塑变生热;裂纹区域温度呈现增长速率随时间逐渐下降的特点;平板振动非线性的主要原因是2裂纹面之间以及换能器与平板之间的接触非线性。
Aiming at the problem that the heat generation mechanism in the defect area of the measured object is not deeply studied in the ultrasonic infrared thermal imaging technology, the cracked plate specimen is taken as the research object and the cracked plate specimen is thermally and mechanically coupled by ANSYS / LS-DYNA The vibration signal and the spectrum of the flat plate under the excitation of high frequency vibration were studied. The characteristics of the heat generated by the crack friction and the heat of plastic deformation were analyzed. The simulation and experimental results show that the thermomechanical coupling analysis is feasible for the crack heat generation problem. The heat generation forms mainly include frictional heat generation and plastic deformation heat generation under the high frequency vibration. The crack growth temperature decreases gradually with time. The main reason for the plate vibration nonlinearity is the non-linear contact between the two crack planes and between the transducer and the plate.