Ultrasound excited thermography is used to determine the length of vertical surface breaking cracks. Two methods are proposed based on the analysis of the maximum temperature reached along the line containing the crack and the time at which the maximum temperature occurs. It is shown that, for short bursts, the full width at half maximum of the maximum temperature curve provides the crack length, and that the time at which the maximum temperature occurs increases beyond the crack tip. The range of application of the methods is analysed and the validity is checked taking data on samples containing artificial calibrated cracks.

中文翻译：

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使用振动热成像法确定表面破裂裂纹的长度

超声激发热成像用于确定垂直表面断裂裂纹的长度。根据对沿着包含裂纹的线的最高温度和最高温度发生时间的分析，提出了两种方法。结果表明，对于短脉冲，最大温度曲线的一半处的全宽提供了裂纹长度，并且最高温度出现的时间增加到超过裂纹尖端。分析了该方法的应用范围，并通过对包含人工校准裂缝的样品进行了数据检验来验证其有效性。