涡流脉冲热像检测中疲劳裂纹的检出概率

在涡流脉冲热像检测中，检出概率是评价检测可靠性的最重要的指标之一。通常，检出概率是指在特定检测条件下特定尺寸的缺陷被检出的概率。首先，以含有不同尺寸疲劳裂纹的金属平板试件为研究对象，通过正交试验方案设计，完成了对不同检测条件下不同尺寸裂纹试件表面热响应信号的提取；然后，采用线性回归模型建立了裂纹区域的热响应信号与裂纹尺寸的定量化关系，并采用极大似然估计法给出了裂纹检出概率模型中的具体参数；最后，基于Wald方法求得了检出概率的置信区间，并绘制了检出概率曲线。研究成果可为涡流脉冲热像检测的可靠性评估提供量化依据。

Probability of detection for fatigue crack in eddy current pulsed thermography

Probability of detection(POD) is one of the most important indexes to evaluate the reliability of detection in eddy current pulsed thermography(ECPT). Generally, the probability of detection is defined as the probability that the defect with fixed size is detected under the given detection conditions. Firstly, a series of metal plates with different lengths of fatigue cracks were introduced to obtain the thermal response signals through the design of orthogonal experiment. Secondly, a linear regression model was established to describe the relationship between thermal response signals and crack lengths, and the maximum likelihood estimation(MLE) method was employed to achieve the specific parameters of the crack POD model. Finally, the resulting confidence interval of POD was presented based on Wald method, and the curves of POD were drawn. The research results can provide a quantitative evaluation method for detection reliability in ECPT.