复合材料结构冲击损伤检出概率的试验研究与分析

复合材料结构在服役过程中遇到的损伤主要来自于意外冲击, 会产生永久性的凹坑。为了得到凹坑的检出概率, 采用最大似然估算法对一般目视检测(GVI)和详细目视检测(DET)的两种损伤检出概率模型(POD评估模型, 即累积对数正态模型和对数奇函数模型)中的参数进行评估; 开展详细目视检测的试验研究, 并根据检测数据对POD模型进行了验证。结果表明: 凹坑深度的检出概率曲线更符合累积对数正态模型。绿色板的凹坑比黑色板更容易被检出, 且检测角越大越容易被检出。目视勉强可见损伤(BVID)的门槛值在0.35~0.8 mm之间。

Experimental study and analysis on probability of detection forimpact damage of composite structures

Impact damage was the key damage type encountered by composite structures in service, which can produce permanent dents. In order to obtain the probability of detection(POD)of dents, the maximum likelihood method was used to calculate parameters of two POD models (the cumulative lognormal model and the log odds model) for general visual inspection (GVI) and detailed visual inspection (DET). Experimental DET study was performed and POD models were verified by test data. The results indicate that the cumulative lognormal model is fit for the POD of dents. Compare with black boards, the dents on green boards can be detected easier, and with the increase of inspection angle, the dents are more likely to be detected. Barely visible impact damage (BVID) thresholds are between 0.35 mm and 0.8 mm.