摘要
碳纤维复合材料(carbon fiber reinforced polymer,CFRP)的多相体系结构特点使得其在加工和使用过程中易产生分层、孔隙和脱粘等缺陷/损伤。缺陷/损伤的存在会极大影响材料的使用寿命,传统的检测方法难以实现对CFRP内部不同类型和大小的缺陷/损伤的准确识别,因此可远距离激励及大角度入射的激光超声技术在CFRP缺陷/损伤无损检测中有良好的应用前景。本文基于激光热弹效应,采用有限元方法分析了不同参数脉冲激光作用下CFRP内部的温度、应力和应力位移分布,并对超声波在碳纤维不同方向的传播特性进行了对比研究。在此基础上,在多层CFRP层间设置缺陷,通过对反射回波信号的特征分析实现对CFRP分层缺陷的定位。研究结果表明,当分层缺陷位于一、二层之间时,通过反射纵波可以实现对缺陷长度不小于0.1 mm的分层缺陷的定位检测,不同探测点的检测误差都可以控制在2%以内。当缺陷位于二、三层之间时,利用反射回波也能检测到长度大于0.5 mm的分层缺陷。
The multiphase structural characteristics of carbon fiber reinforced polymer(CFRP)make it easy to defects/damages such as delamination,porosity,and debonding during processing and use.The existence of defects/damages can greatly affect the service life of materials,and traditional detection methods are difficult to accurately identify different types and sizes of defects/damages inside CFRP.Therefore,laser ultrasonic technology that can be excited from a long distance and incident at a large angle has good application prospects in non-destructive testing of CFRP defects/damages.Based on the laser thermoelastic effect,the finite element method is used to analyze the temperature,stress,and stress-displacement distribution inside CFRP under the action of pulse lasers with different parameters.And the propagation characteristics of ultrasound in different directions of carbon fiber are compared and studied.On this basis,defects are set between multiple layers of CFRP,and the localization of CFRP delamination defects is achieved by analyzing the characteristics of reflected echo signals.The research results show that when the delamination defect is located between the first and second layers,the positioning and detection of delamination defects with a length of not less than 0.1 mm can be achieved by the reflecting longitudinal waves,and the detection error of different detection points can be controlled within 2%.When the defect is located between the second and third layers,delamination defects with a length greater than 0.5 mm can also be detected using reflected echoes.
作者
李琪鑫
程小劲
吴项南
张汉国
尚建华
LI Qixin;CHENG Xiaojin;WU Xiangnan;ZHANG Hanguo;SHANG Jianhua(School of Mechanical and Automotive Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;College of Information Science and Technology,Donghua University,Shanghai 201620,China)
出处
《光电子.激光》
北大核心
2025年第12期1293-1300,共8页
Journal of Optoelectronics·Laser
基金
国家自然科学基金面上项目(5217321)资助项目。
关键词
碳纤维复合材料(CFRP)
热弹效应
激光超声
有限元法
分层缺陷
carbon fiber reinforced polymer(CFRP)
thermoelastic effect
laser ultrasound
finite element method
delamination defects
