The effect of uniaxial prestress on impact resistance of composite

Composite materials have been widely used in the aerospace industry due to their high specific strength, high specific stiffness, good heat resistance and great designability. In practical situations, composites may be stroked by foreign objects under compressive prestress. Therefore, it is of great engineering meaning to investigate impact resistance of composite materials under prestress. In the present work, the impact responses of composite plate subject to compressive prestress are studied experimentally and numerically. At first, a series of ballistic impact tests were conducted on composite plates through gas gun system where a specially designed fixture was employed to exert uniaxial compressive prestress on the target plate. Then the corresponding numerical models were established in ABAQUS. Combining the experimental and numerical results, the effects of pre-compressive stress on the impact responses of composite plate were analyzed. Results show that under uniaxial compressive prestress, four damage mechanisms including the weakening of flexural stiffness, the increasing of bending stiffness mismatch coefficient, the deformation of center and the inhibition of matrix crack growth are found. Layering angle of the target plate is believed to be the controlling key to different damage mechanism.