超声红外热像技术中金属平板裂纹的生热特性

发布时间：2018-04-08 11:39

本文选题：金属平板　切入点：裂纹生热　出处：《红外与激光工程》2015年05期

【摘要】：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。
[Abstract]:Ultrasonic infrared thermal imaging technology is a new nondestructive testing technology. The study of thermal characteristics of defect region is helpful to the formulation of optimal detection scheme.The experimental results show that the temperature rise in the same side of the crack region is more obvious than that in the other side, but the overall heat generation efficiency of the crack surface is stable when the ultrasonic excitation acts on the metal plate with penetrating cracks.In view of the above experimental phenomena, the simulation model corresponding to the experimental system is established by using explicit finite element method, and the mechanical-thermal coupling analysis is carried out.In the simulation model, the piezoelectric force analogy method is used to simulate the inverse piezoelectric effect of ultrasonic transducer, and the dynamic relaxation simulation is introduced to simulate the effect of pretightening force on the initial state of the measured plate.The results of simulation and experiment show that the temperature distribution of crack area and the heat generation law of crack surface are consistent, and the relationship between heat generation efficiency of crack surface and friction force and relative velocity of crack surface is established.It is revealed that the change of the contact state of the crack surface caused by the pretightening force between the tool rod and the measured plate is the direct reason for the heat generation of the crack moving to the same side of the excitation.
【作者单位】：装甲兵工程学院机械工程系;
【基金】：军队科研计划项目
【分类号】：TG115.28

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