基于持续加热的热波无损探伤参数优化

Parameter Optimization in Thermal Wave NDT with Uniform Heating

确定的加热时间和加热强度一直是持续加热方式的热波无损检测技术中的关键问题,利用仿真的方法,对带有缺陷的材料的热传导过程进行模拟。通过观察分析和计算结果,认为在假设条件下,加热对象任意点上升的温度与加热强度的比值为一常数;在持续加热一段时间后(该时间与加热强度无关)加热对象内任意一点温度上升的速度为相等的常数。这对红外热波无损探伤的定量检测和评估、加热强度的确定、加热参数的优化等奠定了理论基础。

The determining of time and intensity of heating is on important problem of thermal wave NDT with uniform heating. In this paper, numerical computing was used to simulate the process of heat conduction in material with defect and to study on changing orderliness of temporal spatial thermal distribution. Observing and analyzing the result, conclusions are as follows： in given conduction, the rate of changed tmperature of any part of heated object and heat flux is a constant; when heating time is long enough（ the time is not related to heat flux）, the rate of changed temperature of any part of object is a constant. These phenomena show the relationship between the biggest temperature contrast and heat flux, which provides theoretical basis to determine intensity of heating and optimize the parameter of heating and lay a foundation for quantitative testing and evaluation of thermal wave NDT.