Interlaminar fracture toughness of glass and carbon reinforced multidirectional fiber metal laminates

CARALL and GLARE type multidirectional fiber metal laminates were subjected to interlaminar fracture toughness tests by End Notched Flexure method. The critical strain energy release rates were calculated based on authors developed methodology of recent analytical Enhanced Beam Theory, and then verified by standardized experimental Compliance Calibration method. With increase of fiber orientation angle (0°, 45°, 90°) at the metal-composite interface, the determined critical strain energy release rate significantly decreased. Simultaneously, the growing contribution of mode I in resulting mode mixity ratio at the crack tip was revealed. Performed experimental tests were supported by Finite Element Analysis by Cohesive Zone Method.