Quantitative microbolometer-based thermoelastic stress analysis
Quantitative microbolometer-based thermoelastic stress analysis
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基于定量微测辐射热计的热弹性应力分析
DOI：
10.1016/j.optlaseng.2022.107276
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发表时间：
2023
影响因子：
4.6
通讯作者：
J. Dulieu‐Barton
中科院分区：
文献类型：
--
作者：
I. Jiménez;D. Bull;O. Thomsen;J. Dulieu‐Barton
使用微测辐射热计进行热弹性应力分析(TSA)具有显著降低部署成本的潜力，并且与更昂贵、更笨重且不那么坚固耐用的基于光子探测器的红外摄像机相比，还可以提供更紧凑、更轻便的解决方案。然而，微测辐射热计在响应时间和灵敏度方面的性能不如光子探测器。随着微测辐射热计在TSA中的使用越来越广泛，现在是时候设计一种方法来评估微测辐射热计的性能，并确定在TSA中使用这种系统的局限性。设计了一种模拟方法，能够研究微测辐射热计响应时间对瞬时信号(例如来自TSA的信号)的影响。由于TSA涉及测量通常由正弦循环加载引起的微小的瞬时温度变化，因此该模拟方法还包括噪声非正弦信号的影响。为了识别循环载荷造成的任何有害影响，还使用光学斩波器和黑体源产生了瞬时温度变化。研究的变量包括信噪比(SNR)、不同波形的影响、信号均值的变化以及内置系统特性，如降噪。提出了一种新的经实验验证的校准方法，该方法考虑了内置降噪功能引入的微测辐射热计响应时间和滚动平均值。结果表明，该标定方法不受试件材料和摄像机帧速率的影响，并在含隐藏裂纹的CFRP试件上进行了验证。
The use of microbolometers for Thermoelastic Stress Analysis (TSA) has the potential of substantially reducing deployment costs, as well as providing more compact and lightweight solutions in comparison to more costly, bulky and less rugged photon detector based infrared cameras. However, microbolometer performance in terms of response time and sensitivity is less than what can be achieved with photon detectors. As the use of microbolometers for TSA is becoming more widespread, it is timely to devise a means of assessing microbolometer performance and identifying the limitations of using such a system for TSA. A simulation approach is devised that enables the effect of the microbolometer response time on transient signals (such as that from TSA) to be investigated. As the TSA involves measuring a small transient temperature change, usually induced by sinusoidal cyclic loading, the simulation approach also includes the effect of a noisy non-sinusoidal signal. To identify any deleterious effects cause by a cyclic load, the transient temperature change is also generated using an optical chopper and a black body source. The variables studied are the Signal-to-Noise Ratio (SNR), the impact of different waveforms, variation in the signal mean, as well as in-built system features such as the noise reduction. A new experimentally validated calibration approach is presented that accounts for the microbolometer response time and rolling averages introduced by inbuilt noise reduction features. It is shown the calibration approach is independent of specimen material and camera frame rates, and it is demonstrated on a CFRP test specimen containing a hidden crack.