超声红外锁相热像中金属疲劳裂纹的生热特性

发布时间：2019-01-18 08:16

【摘要】：超声红外锁相热像技术是一种将调制激励和锁相技术应用于红外热像检测的新型无损检测技术。针对缺陷生热及传热研究中存在的摩擦生热过程难以有效模拟、缺陷内部生热机理不清等理论问题,采用电-力类比方法,建立了含疲劳裂纹金属平板与超声激励系统的有限元模型,研究了调制超声激励下裂纹区域和裂纹面的生热特点,结果表明:在调制超声激励下,裂纹区域生热呈现出周期性上升的特点,因预紧力的作用,靠近激励同侧的裂纹面区域生热更明显。基于仿真分析和Green函数,建立了裂纹摩擦生热的传热理论模型,进一步探究了裂纹区域温度分布规律;最后利用被测平板上下表面温度比值(P值)对热源深度进行了估计,证明了仿真结果与理论计算的一致性。研究成果将进一步丰富超声红外锁相热像技术的理论基础。
[Abstract]:Ultrasonic infrared phase-locked thermography is a new kind of nondestructive testing technology, which applies modulation excitation and phase-locking technology to infrared thermal image detection. In view of the theoretical problems in the study of heat generation and heat transfer of defects, such as it is difficult to simulate the heat generation process of friction effectively, and the mechanism of heat generation in defects is unclear, the electric-force analogy method is used. The finite element model of metal plate with fatigue crack and ultrasonic excitation system is established. The heat generation characteristics of crack region and crack surface under modulated ultrasonic excitation are studied. The results show that: under modulated ultrasonic excitation, The heat generation in the crack region shows the characteristic of periodic rise, and the heat generation near the same side of the crack surface is more obvious due to the effect of the prestressing force. Based on the simulation analysis and Green function, the heat transfer model of crack friction heat generation is established, and the temperature distribution in crack region is further investigated. Finally, the depth of the heat source is estimated by using the ratio of the upper and lower surface temperature of the measured plate (P value), which proves that the simulation results are consistent with the theoretical calculation. The research results will further enrich the theoretical basis of ultrasonic infrared phase-locked thermal imaging technology.
【作者单位】：南昌航空大学无损检测技术教育部重点实验室;装甲兵工程学院机械工程系;北京特种车辆研究所;
【基金】：无损检测教育部重点实验室开放基金(ZD201529007)
【分类号】：TN219

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