A Multi‐View Analysis on the Longitudinal Half Fixed Beam Method for Mode III Delamination of Composite Laminates

ABSTRACT The feasibility and applicability of longitudinal half fixed beam (LHFB) test of CFRP unidirectional laminates is investigated from multiple perspectives in this work. A three‐dimensional finite element model is used to simulate the LHFB specimen, employing the Virtual Crack Closure Technique (VCCT) in conjunction with the B ‐ K Criterion. Comparisons between solid‐loading and simplified line‐loading boundary conditions reveal no significant differences in results. The applicability of various data reduction methods is evaluated, demonstrating that the Compliance Calibration Method is effective in determining the mode III strain energy release rate. The distribution uniformity of strain energy release rate along the crack front is analyzed through parameter analysis, including geometric dimensions of the specimen and the initial delamination length. The results indicate that this test method enables an almost uniform distribution of mode III strain energy release rate, but the mode II component at the crack edge remains non‐negligible. However, the proportion of the mode II component can be minimized by optimizing the geometric dimensions of the specimen.