Evaluation of in-plane shear test methods for composite material laminates

In-plane shear properties of composite material laminates are very important in structural design of composite material. Four commonly used in-plane shear test methods were introduced in this paper. In order to study the differences of various shear test methods, two ASTM standard in-plane shear test methods for composite material laminates were experimentally investigated. They are ±45℃ tensile shear test (ASTM D3518) and V-notched rail shear test (ASTM D7078). Five types of composite material laminates composed of E-glass fiber fabric and vinyl ester resin were utilized, whose stacking sequences are [0]3s, [0/90]3s, [CSM/0/90]2s, [±45]3s and [(0/90)2/(±45)2/(0/90)2]s, respectively. The test results indicate that the±45℃ tensile shear test can predict shear moduli of composite material laminates accurately. However, the predictions of shear strength using±45℃ tensile shear test are significantly lower than those of V-notched rail shear test.