红外热波检测热激励源的优化

Study of Optimizing Thermal Excitation Signal in Thermal Wave Testing

为解决热激励信号的选取问题,从热波检测的原理出发,建立了求解试件温度分布的偏微分方程组。通过分析方程组,发现热激励信号强度与温度升高值成正比关系。先从理论上对其进行推导,并使用ANSYS软件对试件内热传导过程进行数值计算。结果表明,增强热激励信号在脉冲热像法中可以成正比增大最大温差,在阶梯热像法中可以成正比增大各时刻的温差,在锁相热像法中可以成正比增大幅值差,为热激励信号强度的定量选取提供了理论依据和具体尺度。

Selecting thermal stimulating signal is pivotal problems in thermal wave testing. In order to resolve it, beginning with the theory of thermal wave testing, a partial differential equation that could work out temperature distributing of sample was established. By analyzing equation group, the relationship between intensity of thermal stimulation signal and temperature change in direct proportion, which was proved by numerical through ANSYS. This conclusion indicates that, when boosting up intensity of thermal stimulation signal, the biggest temperature change will increase in proportion as in pulsed thermography, temperature change will increase in proportion as in step heating thermography; breadth change will also increase in proportion as in lock-in thermographic testing, which provides theoretical basis and implementing measure.