시뮬레이션 기법에 의한 CFRP 적층각에 따른 강도 예측 연구

Abstract

In recently, they try to increase the efficiency for energy usage related to eco-friendly about transport machine, aviation⦁space industry and civil engineering construction etc in various industry. By making lightweight mechanic structure. It can raise the efficiency about energy usage. CFRP is one of the lightweight materials which have specific strength, specific stiffness and low thermal deformation rate. It have been used in various industry. Especially, in aviation and transport machine industry division. They have been researching to raise the efficiency by using CFRP. But CFRP has been in various showed differently depend on who made this CFRP. Because of those characteristic. It's hard to calculation exact material properties. In generally, to get the exact material properties of CFRP it spend lot's of time and cost. Also it cannot be exact real test because of environment variable. For these reason, we use GENOA, NX Nastran which is used generally and simulate this CFRP. By using GENOA which is composite material exclusive analysis program. Can get approximate value which is similar to real experiment about fiber, matrix, fiber volume ratio, void volume ratio, temperature, stacking angle, absorbtion of composite material. But NX Nastran is limited to composite material. It's hard to get approximate value compare with real test. Also MCQ is possible to get material properties about ply by analysis about laminate. In this study, following the ASTM standard, it's possible to make specimen and do research which can valuate tension, compression, shear. And by using NX Nastran and GENOA simulate the tension, compression, shear. After get CFRP laminate material properties CFRP ply is reconstructed by MCQ. By using this material properties NX Nastran, GENOA it was re analysis. After simulate about tension, compression and shear compared each material properties. It was valuated. The result obtained from this study is as follows.

1. When simulate to NX Nastran and GENOA with real test material properties. Linear section is almost same with Stress-Strain Curve. But nonlinear section is a few difference. For these reason, it didn't consider nonlinear properties of matrix.

2. The material properties which is reconstructed with MCQ and the stress-strain curve have no space to write the environment variable of Nastran. It caused bad result before I tried first as a result. It need to re analysis by using material card which is apply to nonlinear properties of matrix.

3. After re analysis result YCC and XYS is graph are almost similar by applying reconstructed material properties and stress-strain curve of matrix for GENOA.

4. When considering the simulation result and stress-strain curve of real test result XXT hasn't affected to matrix section.

5. The result which is applied with GENOA of reconstructed material properties. Stress section is almost similar with real test. In strain, it has little bit lower than real test. The reason why during the real test it was slipped. That's why the result is different.