Composite failure prediction of π-joint structures under bending  

作　　者：黄红梅 袁慎芳 

机构地区：[1]Aeronautic Key Lab for Smart Materials and Structures,Nanjing University of Aeronautics and Astronautics [2]College of Physics and Electronic Engineering,Xuzhou Normal University

出　　处：《Optoelectronics Letters》2012年第2期121-124,共4页光电子快报（英文版）

基　　金：supported by the National High Technology Research and Development Program of China (No.2007AA03Z117);the Key Program of National Natural Science of China (No.50830201);the Ph.D. Teacher,s Research Project of Xuzhou Normal University

摘　　要：In this article, the composite π-joint is investigated under bending loads. The ＂L＂ preform is the critical component regard- ing composite π-joint failure. The study is presented in the failure detection of a carbon fiber composite π-joint structure under bending loads using fiber Bragg grating （FBG） sensor. Firstly, based on the general f＇mite element method （FEM） software, the 3-D finite element （FE） model of composite π-joint is established, and the failure process and every lamina failure load of composite π-joint are investigated by maximum stress criteria. Then, strain distributions along the length of FBG are extracted, and the reflection spectra of FBG are calculated according to the strain distribution. Finally, to verify the numerical results, a test scheme is performed and the experimental spectra of FBG are recorded. The experimental results indicate that the failure sequence and the corresponding critical loads of failure are consistent with the numerical predictions, and the computational error of failure load is less than 6.4%. Furthermore, it also verifies the feasibility of the damage detection system.

关 键 词：Carbon fibers Damage detection Finite element method STRAIN Three dimensional 

分 类 号：TH165.3[机械工程—机械制造及自动化]