Investigation of interlaminar mode-I fracture toughness of corrugated composite plates

In this study, delamination of the corrugated composite plates made of unidirectional glass fibers and polyester resin has been investigated. The samples are fabricated by hand lay-up process based on ASTM-D5528 standard. Using experimental tests, the strain energy release rate in mode I has been calculated for composite corrugated specimens by the prevalent method of interlaminar failure. Also, the samples were simulated as a double cantilever beam by Abaqus software and the mechanical properties of unidirectional glass/polyester composite and the results of numerical solution are also obtained. Fracture surfaces of experimental samples were analyzed by scanning electron microscope. Force-displacement curves obtained from experimental and numerical methods have been campred to find the material behavior and calculate the strain energy release rate for different samples with three pre-crack lengths. The results show that the corrugated composite plates have a higher interlaminar fracture toughness rather than flat samples and the four-wave sample with a crack length of 60 and 65 mm has the highest values of the strain energy rate released, equal to 963.77 and 705.95 , respectively.