Study On In-plane Compressive Strength Of Carbon Fiber Reinforced Laminated Composites

Carbon fiber reinforced laminate composite has high specific strength and high specific modulus. It is an ideal structural material to lose weight and reduce energy consumption in industrial field. Carbon fiber reinforced composite was first widely used in aeronautical and space technologies. With the decline in production costs, it is increasingly used in sport equipments, automobile, and so on. 2D woven composite laminated plates is woven by reinforced fibers in two dimensions, which is different from unidirectional monolayer. Its main character is that material can be reinforced in two dimensions. That makes the strength of laminate get improvement in two mutually perpendicular direction.A composite laminate was made up of two kinds of carbon fiber sheets, diagonal and satin, by [0/45/-45/90/90/-45/45/0]. Diagonal cloth was placed at angles of +/-45 and satin cloth at angles of 0/90. The in-plane compressive strength of composite laminate was investigated theoretically and experimentally. Quasi-static and dynamic compressive loading were applied to the laminates. The obtained results are outlined as following:(1) Based on the classical laminated theory, predicted Young’s modulus of composite laminates varied a little with the change of angle. In-plane shear modulus has little influence on in-plane young’s modulus of laminates, which means the laminate has almost the same Young’s modulus in all directions. This kind of laminate has no obvious faults in every direction.(2) The in-plane compressive modulus increase with the increase of loading angle. The static failure strength also enhance with the increase of loading angle. But the failure strain change little.(3) Under compression loading of dynamic impact, in-plane initial modulus of laminate of 30 and 90 degree angle increased with the strain rate. The modulus of laminate of 60 degree angle didn’t show strain rate effect. The failure strength has obvious positive strain rate effect.(4) High speed video study found that the specimens were broken initially in 3 kinds of modes: splitting at supporting end, splitting at loading end and buckling of fiber layer. No matter what kind of failure mode comes first, delamination, buckling and breaking can be seen in all kinds of situation.(5) Comparing with quasi-static experimental results, dynamic compression caused lower failure strain. The relationship between static and dynamic failure strength is complicated.