超声红外检测中裂纹微观界面生热的数值模拟

Numerical simulation of the heat generated by the microcosmic interface of cracks in ultrasonic infrared detection

从超声波传播和声机热转换的理论角度,阐述了红外无损检测的工作原理。采用ANSYS和ABAQUS 软件建立超声红外无损检测的有限元分析模型,结合模态和谐响应分析手段,总结出超声激励的合理频率,有效地避开了结构共振现象且获得了较好的成像效果。通过数值模拟、热力学第一理论以及声波传播理论,对裂纹微观界面的生热机理进行了研究,发现超声激励下裂纹生热的速率极快,近表面的裂纹处生热量大,温升高,进一步证明了超声红外检测的高效性和可行性,为科研实验和工程检测提供了相关的理论依据。

The infrared nondestructive testing was described from the theoretical perspective of ultrasonic propagation and the acoustic structure thermal conversion. Then, the finite element model of ultrasonic infrared nondestructive testing was established by ANSYS and ABAQUS. Besides, the reasonable frequency of ultrasonic excitation was given by modal and harmonic response analysis method. Thus, it could effectively avoid the structural resonance phenomenon and obtain a good imaging result. Heat generation mechanism of micro crack interface was researched through numerical simulation, thermodynamics first law and acoustic propagation. It was found that the rate of heat generation was very fast, the quantity of heat generation was large and the temperature rise was high in the crack near the surface under ultrasonic excitation. It could further prove the feasibility and efficiency of ultrasonic infrared detection and provide the theoretical basis for scientific experiment and engineering test.