Elastic behaviour of composite structures under low velocity impact

The results of a study on the behaviour of glass cloth/polyester panels under low velocity impact are reported. The experimental load/time curve in the elastic region showed good agreement with that predicted by a simple analytical model, based on energy considerations, using elastic properties obtained by static tests. The structural rigidity of the panels was not significantly affected by premature local shear damage, due to the concentration of load, even after first fibre failure. The strength of the material was found to be strongly rate-dependent; as a consequence the response of the structure in the post-elastic region cannot be predicted from the results of static tests.