Composite Opening Reinforcement Of Experimental Research And Design Analysis

The question about the composite repair is regarded important for the need of aircraft design, and a large amount of study has been done in connection with it. But to some new case in practical application, our studies have limitation. In the previous study, focus at the laminate thin plane, small cut-out and some traditional reinforcement methods. In this paper, two kind of traditional reinforcement methods, and the work of the test and FEM study, paramate design about a new repair method have been studiedby the theoretic, numerical calculation and experiments. They are as follows:1. To carry out the static mechanics analysis of the repaired plate, the test and Finite Element Model (FEM) about composite medium thick plate with flange repaired and secondary cocure reinforcement have been completed.The resoult is that eccentric bending moment leaded by the physical dimension asymmetric is the prime reson of the structure failor.2. The statics tension test about the experiments of five kinds of reinforcement with different stitch parameters with respect to a new repaired means—stitch reinforcement and without any reinforcement have been completed. We find that the last failing load of these tests is likelihood. Used the Link Element given by Ansys to simulate the stitch threads, The FEM study about of two case have been completed. The resolute is perfect.3. To give a reference about the stitch parameter design, Based on the boundary -layer theory and the minimization complementary energy theory, the numerical resolute of interlaminar and innerlaminar stress near the edge have been given. The resolute have been Compaied with others, the conclusion is credibility.4. Based on the numerical resolute,consider the out-of-plane strength, the elastic characters and tension strength of the stitch thread ,refer to the average stress fracture criterion, those stitching parameter needed such as the distancebetween the edge and stitch line, the needle space, the stitch thread radius can be given. The resolutes of the repaired is checked by the FE. At last we find that the distribution of the out-plane stress of stitched laminate is improved as these stitch parameter be used through FE.