Abstract
This paper presents an image analysis on the flexural behaviors of CFRP box beams with two different CFRP laminate structures: quasi isotropic (QI) and cross ply (CP) laminate. Image analysis is conducted in order to measure the deformation field around the center span of CFRP box beams, and strains, principal strains, principal stresses, and Tsai-Wu index are calculated consequently. QI and CP showed a different flexural response due to their laminate structures, but both showed a final brittle failure in upper flange and web. Strains, principal strains, and principal stresses clearly show characteristic distributions around the center span, and some of them indicate local concentrations near loading points. Tsai-Wu index explains fracture origin location possibly for QI, but it does not for CP.
