The effect of raw-material related parameters on the impact strength of sandwich boat-laminates

A new impact test method is presented using an instrumented falling weight impact arrangement with a pyramid-shaped impactor. The method allows the observation of effects occurring in the different phases of a penetrating impact. The method is most suitable for sandwich laminates, especially if full penetration of the sandwich is of major interest. The effects of certain raw-material related parameters on the impact strength of sandwich boat-laminates is determined. The results are based on a test series consisting of 26 laminates of basically similar geometry, but of various fibre materials, reinforcement types, lay-ups and matrix materials. A basic laminate, representing the current "state-of-the-art" in the boat-building industry, is tested for comparison. The criterion for comparing the impact strength of the laminates is the energy absorbed up to full penetration of the laminate, which corresponds to the point of losing water-tightness. In order to achieve a comprehensive representation of the overall performance of the laminates in boat structures, tensile, compressive and interlaminar shear tests of the face laminates were also performed.