Paper number 391

IN-PLANE MECHANICAL PROPERTIES OF CF/EPOXY 3-D ORTHOGONAL INTERLOCKED FABRIC COMPOSITE

Naoyuki WATANABE¹, Shigeomi OSHIBA², Takashi ISHIKAWA³

1Associate Professor, Department of Aerospace Engineering
Tokyo Metropolitan Institute of Technology, 6-6 Asahigaoka, Hino-city, Tokyo 191, JAPAN
2Graduate Student, Department of Aerospace Engineering
Tokyo Metropolitan Institute of Technology
3Section Head, Airframe Division, National Aerospace Laboratory
6-13-1 Ohsawa, Mitaka, Tokyo 181, JAPAN

Summary

Tensile tests were executed for obtaining the in-plane mechanical properties of CF/Epoxy 3-D orthogonal interlocked fabric composite. And the prediction of in-plane stiffness, simulation of damage growth and evaluation of ultimate tensile strength are carried out for the models with undulation of in-plane tows by using the 3-dimensional FEM analyses based on the homogenization method. The prediction of damage growth behavior such as transverse crack and delamination is very reasonable, and the predicted stress-strain curve is in good agreement with the experimental results. As for the ultimate failure, the predicted results were considered to be generally in good agreement with the experiments, considering the uncertainty and scatter in the experiments. The present results would give the effective guidelines for predicting the initial failure, damage growth and ultimate tensile strength of this complicated 3-D composites, although more detailed experimental observations were required.

Keywords

3-D orthogonal interlocked fabric composite, tensile test, 3-D FEM analysis, homogenization method, quadratic failure criteria, damage growth simulation