2025 Volume 74 Issue 1 Pages 47-54
Carbon fiber reinforced plastic (CFRP), which has the characteristics of lightweight, high specific strength and high specific stiffness, is applied to various structures such as aircraft and automobile. In particular, strength evaluation of woven CFRP used for structural components is still challenging. Currently, the strength evaluation using homogenization method is widely studied. However, for homogenization method, some precise dimensional measurements are needed during the modelling process, so a simpler method is desirable. In addition, strength evaluation using actual product of CFRP is the mainstream. There is also the issue of cost. Therefore, in this study, modeling and analysis using orthogonal anisotropy are conducted on twill weave CFRP specimen and structural sample by the general-purpose structural analysis software NASTRAN. Tensile and bending tests are conducted on the specimen, and loading tests using a fixture are conducted on the structural sample for comparison with the analysis. Strength evaluation is also conducted using the knee-point, which initial fracture begins to occur. As a result, the modulus of elasticity obtained from the analytical tensile test is in good qualitative agreement with the experimental value. The strength evaluation using 22.5° pitch stress from the analysis and the knee-point shows availability to predict the initial fracture behavior of the specimen and structural sample.
