超声背散射信号递归定量分析无损表征CFRP孔隙分布仿真
Simulation on non-destructive evaluation of CFRP void distribution with recurrence quantification analysis of ultrasonic back-scatter signals

针对碳纤维增强树脂基复合材料（Carbon fibre reinforced plastics，CFRP）孔隙分布对其力学性能有不可忽略影响的问题，提出对超声背散射信号进行递归定量分析（Recurrence quantification analysis，RQA）的方法来表征CFRP孔隙尺寸和位置分布。建立孔隙直径D范围为26~70 μm的3组含球形孔隙且孔隙位置分布不同的CFRP模型，3组模型的孔隙间距d分别为0.21 mm、0.14 mm和0.09 mm，对模型进行仿真计算，采用RQA方法分析超声背散射信号。研究发现，相同孔隙位置分布时，递归度PRR（Recurrence rate）随D的增加而减小；相同孔隙尺寸分布时，PRR随着孔隙间距d减小而增大，d=0.09 mm时模型的PRR始终明显高于其余两组，D<50 μm时，d=0.14 mm与d=0.21 mm模型PRR之间差别明显，D ≥ 50 μm时差别较小。结果表明，不同孔隙分布情况下PRR均存在差异，PRR可用于CFRP孔隙分布表征。 The void distribution of carbon fibre reinforced plastics (CFRP) has an important effect on its mechanical properties. Focusing on this problem, recurrence quantification analysis (RQA) of ultrasonic back-scatter signals was proposed to characterize void size and position distribution. Three groups of CFRP models with spherical voids were established, in which each model had different void position distribution. The void diameters D ranged from 26 μm to 70 μm, and the distance d of voids was 0.21 mm, 0.14 mm and 0.09 mm, respectively. Based on these models, the back-scatter signals were analyzed by RQA method. The simulated study shows that, recurrence rate PRR decreases with D increasing when the void position distribution is the same. If the void size distribution is the same, PRR increases with d decreasing. The PRR of models with d=0.09 mm are always higher than the other two groups. There is significant difference in PRR between d=0.14 mm and d=0.21 mm models when D<50 μm. But the difference is small when D ≥ 50 μm. The results demonstrate that there is difference in PRR on different void distributions, PRR can be used to characterize different void distributions in CFRP. 国家重点基础研究发展计划（2014CB046505）；国家自然科学基金（51275075）