The influence of the type and positioning of the interface material on the impact behaviour in two-layered epoxy pieces

Abstract

Uniform cut sections, made from room temperature cured epoxy slabs, were prepared. Two such pieces were juxtaposed with the common width face having varying areas of its face smeared with a thermosetting adhesive bond material and/or solid lubricant material. Impacts were done with one of the width faces of the two-layered coupons facing the pendulum strikes. The instrumented impact testing machine used for experiments yielded data on maximum load, time involved and energy absorbed during the experiment. Three sets of samples were subjected to such impact. In one, the coupons had one-third of the common face on either ends of the length of the sample smeared with adhesive resin, which was allowed to set at room temperature before subjecting to impact. These experiments yielded a set of values and macroscopic failure features which was different from the case where instead of the adhesive thermosetting resin, the same area was occupied by a solid lubricant. The investigation was further extended for a third case where a hybrid interface involving two onethird ends with thermosetting resin while middle one-third had solid lubricant material within it. This hybrid showed a trend which was an admixture of the other two cases as regards the macroscopic failure features, while the mechanical data showed a trend which was quite different from the earlier (single interface material bearing) cases.