重型铝合金结构裂纹振动红外热像检测的建模和分析

为了实现重型铝合金承力结构裂纹的振动红外热像无损检测，优化检测条件，提出振动热像检测的数学模型，用解析法研究金属裂纹振动热像检测的检测条件和影响因素。用试验说明振动热像法的有效性，用强迫振动理论和瞬态传热理论对振动热像法进行数学建模和解析计算，得出裂纹区表面温升与裂纹阻尼、激振力幅值、激振频率、激振时间、裂纹深度等力学参数的函数关系。结果表明，理论计算结果与试验现象相吻合，所提出的解析模型可以精确地描述多种主要力学参数对振动热像的影响规律。以建模和解析法研究振动热像法的振动发热规律对揭示其内在规律和建立标准操作参数窗口具有普遍意义

Modeling and Analysis of Vibrothermography of Cracks in Heavy Aluminum Alloy Structures

In order to inspect cracks of heavy aluminum alloy structures and to optimize the test conditions, the model of vibrothermography (VT) is presented, and the test conditions and factors are studied by analysis method. The effectiveness of VT for crack inspection is illustrated with an experiment, and then the modeling and calculation of VT are implemented based on the theory of forced vibration and transient heat conduction. The function of the surface temperature increase at the crack area versus the mechanics parameters such as the crack damp, force amplitude, excitation frequency and duration, crack depth, etc. is obtained. The results show that the theoretical data are consistent with the experimental phenomenon, and the influence of various mechanics paramerters on VT can be exactly described by the analytical model presented. The study on the principles of heat generation in VT by the modeling and analysis method has universal significance to reveal the intrinsic mechanism and set up standard windows of operation parameters of VT.