Low velocity impact on polymeric foams

Characterization of polymeric foams

Low-Velocity Impact Testing

IMPACT TESTS are used to study dynamic deformation and failure modes of materials. Low-velocity impact techniques can be classified as plate-on-plate, rod-on-plate, plate-onrod, or rod-on-rod experiments. Two types of plate-on-plate impact tests have been developed: wave propagation experiments and thin-layer high-strain-rate experiments. The plate-on-plate experiments are further classified as...

Low Velocity Impact Damage Prediction in Laminated Composite Plates

In this paper, a finite element model is presented for the transient analysis of low velocity impact, and the impact induced damage in the composite plate subjected to low velocity impact is studied. The failure criteria suggested by Choi and Chang and the Tsai-Hill failure criteria are used for the prediction of the damage in the composite plate; then the effect of various parameters on the im...

Negative Poisson's Ratio Polymeric and Metallic Foams

Foam materials based on metal and several polymers were transformed so that their cellular architectures became re-entrant, ie. with inwardly protruding cell ribs. Foams with re-entrant structures exhibited negative Poisson's ratios as well as greater resilience than conventional foams. Foams with negative Poisson's ratios were prepared using different techniques and materials and their mechani...

Size Effect on the Damaged Areas of Glass/Epoxy Structures under Low Velocity Impact

Most impact tests are carried out on specimens with specific stacking sequence and dimensions to meet standard and experimental limitations. The damaged areas and the resulted reduction in the strength values of specimens may not agree very well with those of real application. In this paper an attempt is made to study the variation in the size of damaged areas due to varying the dimension of te...