We studied the infrared radiation (IR) characteristics of sandstone cracks with different water contents. We propose a new IR-based method to distinguish the initial development and damage point of cracks. The maximum variation of IR variance shows a quadratic relationship with water content. By defining crack initiation and damage using a stiffness stress curve, it can be concluded that the crack initiation and crack damage IR variance thresholds show a quadratic relationship with water content. The proportion of the two thresholds at the maximum IR variation amplitude does not change with increasing water content, yielding ratios of 47.51% and 78.19% for crack initiation and crack damage, respectively. The rock stress threshold of crack initiation and damage show a negative logarithmic relationship with their respective IR variance thresholds with correlation coefficients above 0.90.

我们研究了不同含水量砂岩裂缝的红外辐射 (IR) 特性。我们提出了一种新的基于 IR 的方法来区分裂纹的初始发展和损坏点。IR 方差的最大变化显示出与含水量的二次关系。通过使用刚度应力曲线定义裂纹萌生和损伤，可以得出结论，裂纹萌生和裂纹损伤 IR 方差阈值与含水量呈二次关系。两个阈值在最大 IR 变化幅度下的比例不随含水量的增加而变化，裂纹萌生和裂纹损伤的屈服比分别为 47.51% 和 78.19%。