超声兰姆波与复合材料脱层缺陷相互作用研究

项目名称： 超声兰姆波与复合材料脱层缺陷相互作用研究

项目编号： No.11474195

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 张海燕

作者单位： 上海大学

项目金额： 87万元

中文摘要： 脱层是复合材料中最常见和最严重的损伤模式之一，由于其不可见性、危险性以及复合材料结构本身的复杂性，脱层缺陷的超声兰姆波检测备受关注。实际声散射问题求解困难，为简化计算，在理论上将脱层等效为各向同性模型中的非均质体，数值上仅考虑贯穿整个板宽度的2D脱层，目前研究不能完整地反映兰姆波与缺陷之间的相互作用。鉴于此，本项目将针对纤维增强复合材料板中的局部（3D）脱层缺陷，综合理论、数值模拟和实验，研究兰姆波与缺陷相互作用发生的散射和模式转换问题，实现兰姆波散射声场的高精度求解；建立兰姆波散射声场与缺陷特征之间的关系，探究兰姆波与脱层缺陷相互作用机理；发展有效的信号处理方法，提取纯散射信号并从混叠的多模式信号中分离出所需要的模式；探索基于全波场信息的异常波传播成像算法，提高定量化缺陷图像的分辨率和精度。在学术上提供解决兰姆波散射问题的新途径，在应用上为复合材料脱层缺陷的兰姆波无损检测技术奠定基础。

中文关键词： 超声兰姆波；脱层缺陷；复合材料；相互作用；无损检测

英文摘要： Delamination is one of the most common and serious failure modes in composite laminates.Due to its invisibility,danger as well as the complexity of composite structure itself,ultrasonic Lamb wave detection of delamination defect has received significent attention.Because of the difficulty in solving practical acoustic scattering problem,in order to simplify the calculation,modelling the delamination as an inhomogeneity in the equivalent isotropic model in theory,only considering the 2D delamination across the full width of the laminate,current researches cannot perfectly reflect the interaction of Lamb wave with delamination defect.For local (3D) delamination defects in fiber reinforced composite laminates, combining the theory,simulation and experiment,this project will study the scattering and mode conversion characteristics of the interaction of Lamb wave with the defect so as to realize high-precisionaccurate solutions to Lamb wave scattering acoustic fields.The relationship between Lamb wave scattering acoustic fields and the defect features are established for exploring the mechanism of interaction of Lamb wave with the delamination defect.Effective signal processing method is developed to extract the pure scattered signals and isolate the desired modes.This project will research anomalous wave propagation imaging algorithm based on the full wave field data,so as to improve the resolution and precision of quantitative defect map.The achievements of this project will provide a new academic way for Lamb wave scattering problem and lay the groundwork for Lamb wave nondestructive inspection technique of delamination defects in composite laminates in the application.

英文关键词： ultrasonic Lamb wave;delamination defect;composite laminate;interaction;nondestructive testing