EXPERIMENTAL STUDY ON DAMAGE AND FAILURE BEHAVIOUR OF T300/QY8911 CROSS-PLY LAMINATED COMPOSITE SUBJECTED TO IMPACT

An experimental study on damage and failure of T300 carbon fibre reinforced QY8911 bismaleimide resin laminated composite subjected to low-velocity impact is presented. Three kinds of cross-ply lay-up construction of the laminate were considered. Three-point bending beam specimens were tested with an instrumented drop weight impact tester. The impact load history curve was recorded. By changing impact velocity,the impact energy threshold was determined. The damage mode was examined with SEM and found to be interlaminar shear delamination coupling with matrix cracking in 90°layers. For the sake of comparison,static 3-point bending test was also conducted. The bending load versus deflection curves and failure strength of the two cases have no significant difference. The one dimensional harmonic vibration model of the hammer-beam system was proposed to model the impact dynamic behaviour for the case of below threshold impact. The explanation of ignorance of stress wave propagation effect was given.