Static Indentation and Low Velocity Impact Tests on Sandwich Plates

Abstract

Quasi-static indentation tests and drop-weight impact tests were performed on graphite/bismaleimide (GR/BMI) laminates as well as on foam-core sandwich panels. Impact tests on 8-ply laminates show that the response and damage are similar to quasi-static results. Quasi-static and impact test results on sandwich panels show that the overall response is dependent upon the response of the face sheets and the core. An increase in core density increases the overall load level, panel stiffness, core fracture toughness, and decreases the core compression. A decrease in core thickness decreases the panel stiffness and energy absorption. If the radius of the indenter is greater than the core thickness, penetration of the panel will be delayed and the failure load of the bottom face sheet will increase. The quasi-static and impact responses have the same overall trend, however, the load levels increase in impact tests due to dynamic effects.