超声红外热像技术是一种新型无损检测技术,缺陷区域生热特性的研究有利于最优化检测方案的制定。实验分析表明:超声激励作用于含贯穿裂纹的金属平板时,与激励同侧的裂纹区域温度升高比异侧更明显,但裂纹面总体的生热效率稳定。针对上述实验现象,采用显式有限元方法建立了与实验系统对应的仿真模型,进行了机热耦合分析。在仿真模型中,采用压电-力类比方法模拟超声换能器的逆压电效应,并引入动态松弛模拟预紧力对被测平板初始状态的影响。仿真与实验结果得到了一致的裂纹区域温度分布和裂纹面生热规律,建立了裂纹面生热效率与裂纹面摩擦力及相对运动速度之间的联系,揭示了工具杆和被测平板之间的预紧力使裂纹面接触状态改变是裂纹生热向激励同侧偏移的直接原因。 Ultrasonic infrared thermal imaging technology is a new nondestructive testing technology. The study of the heat generation characteristics in the defective area is conducive to the development of the optimal testing program. The experimental results show that when the ultrasonic excitation is applied to the metal plate with through-crack, the temperature rise in the crack region on the same side of the excitation is more obvious than that on the opposite side, but the overall heat generation efficiency of the crack surface is stable. In view of the above experimental phenomena, an explicit finite element method was used to establish the simulation model corresponding to the experimental system, and the thermal-mechanical coupling analysis was carried out. In the simulation model, the piezoelectric-force analogy method was used to simulate the inverse piezoelectric effect of ultrasonic transducers, and the effect of dynamic relaxation on the initial state of the tested plate was simulated. The results of simulation and experiment show that the temperature distribution and the heat generation of crack surface are consistent, and the relationship between the heat generation efficiency of crack surface and the friction force and the relative velocity of crack surface is established. The relationship between the tool rod and the measured plate The preconditioning makes the change of the contact state of the crack surface is the direct reason that the crack heat is offset to the same side of the excitation.