Infrared thermography has widely been used in observing and recording failure processes. The loading rate is a critical parameter that influences the infrared radiation (IR) in the mechanical experiment. However, little work has been done regarding its influence on infrared radiation. In order to conduct an in-depth study on the influence of loading rates on IR, a series of three-point bending experiments were conducted on PMMA samples for the IR test. Then, the influence was explained through a physical model derived from the first law of thermodynamics. The experimental results showed that under a fixed loading rate, the change rate of the IR emission was constant, and the relationship between the IR emission and loading time exhibited a linear trend. The variation between the change rate of IR emission and the loading rate can be expressed by the exponential function. The insights gained from this study will be of assistance to obverse the loading processes by infrared thermography.

中文翻译：

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加载速率对PMMA红外辐射的影响

红外热成像已广泛用于观察和记录故障过程。加载速率是影响机械实验中红外辐射 (IR) 的关键参数。然而，关于它对红外辐射的影响的研究很少。为了深入研究加载速率对IR的影响，对用于IR测试的PMMA样品进行了一系列三点弯曲实验。然后，通过从热力学第一定律导出的物理模型来解释这种影响。实验结果表明，在固定加载速率下，红外发射的变化率恒定，红外发射与加载时间的关系呈线性趋势。红外发射的变化率和加载率之间的变化可以用指数函数表示。从这项研究中获得的见解将有助于通过红外热成像观察加载过程。