TY - JOUR
T1 - Thickness effect on flexural strengths of laminar carbon fibre composites
AU - Hu, Yunsen
AU - Han, Gang
AU - Cheng, Fei
AU - Hu, Xiaozhi
PY - 2023/5
Y1 - 2023/5
N2 - The thickness dependence of flexural strengths of laminar carbon fibre reinforced polymer (CFRP) plates was investigated experimentally and analytically in this study. This thickness effect was linked to the ply thickness by a simple composite formula. Four different sample thicknesses of 1.48, 2.08, 2.48 and 2.96 mm were tested, and thickness dependent flexural strengths were evaluated by the Strength of Materials (SOM) formula and modelled by the simple composite formula containing the ply thickness. The ASTM standard D7264, recommending 4 mm thick CFRP samples, was justified analytically, i.e., the thickness effect is negligible if W ≥ 4 mm for CFRP plates with typical ply thickness around 120–130μm. The intrinsic tensile strength, independent of the sample thickness, was deduced from all flexural tests by the composite formula, which compared well with the tensile strength from unidirectional tensile tests and the tensile strength estimated from notched flexural samples. The specimen and notch/crack size requirements in ASTM standards for the fracture toughness were also explained analytically.
AB - The thickness dependence of flexural strengths of laminar carbon fibre reinforced polymer (CFRP) plates was investigated experimentally and analytically in this study. This thickness effect was linked to the ply thickness by a simple composite formula. Four different sample thicknesses of 1.48, 2.08, 2.48 and 2.96 mm were tested, and thickness dependent flexural strengths were evaluated by the Strength of Materials (SOM) formula and modelled by the simple composite formula containing the ply thickness. The ASTM standard D7264, recommending 4 mm thick CFRP samples, was justified analytically, i.e., the thickness effect is negligible if W ≥ 4 mm for CFRP plates with typical ply thickness around 120–130μm. The intrinsic tensile strength, independent of the sample thickness, was deduced from all flexural tests by the composite formula, which compared well with the tensile strength from unidirectional tensile tests and the tensile strength estimated from notched flexural samples. The specimen and notch/crack size requirements in ASTM standards for the fracture toughness were also explained analytically.
KW - Carbon fibre reinforced polymer
KW - Flexural strength
KW - Tensile and flexural strengths
KW - Thickness effect on flexural strength
UR - http://www.scopus.com/inward/record.url?scp=85150909565&partnerID=8YFLogxK
U2 - 10.1016/j.tws.2023.110690
DO - 10.1016/j.tws.2023.110690
M3 - Article
AN - SCOPUS:85150909565
SN - 0263-8231
VL - 186
JO - Thin-Walled Structures
JF - Thin-Walled Structures
M1 - 110690
ER -