INFLUENCE OF STRAIN RATE ON BUCKLE FOLDING OF AN ELASTO-VISCOUS SINGLE LAYER

Abstract

The influence of strain rate on the buckle folding behavior of an elasto-viscous layer-matrix model is explored by adopting an end-rotation method, which is capable of excluding the influence of initial geometric perturbation, and by observing the energy variation in the system. The results indicate that, if the strain rate is relatively slow, the folding behavior is in fact the result of both viscous and elastic behavior, and not just the viscosity alone.For two-stage shortening at different strain rates, the final waveform depends on either the earlier strain rate inducing buckling or the later strain rate applied in the post-buckle stage of deformation. If the later strain rate is relatively fast, the final waveform will be similar to the one yielded by the fast strain rate alone, as a substantial amount of elastic energy can be accumulated during the subsequent fast deformation. On the other hand, if the later strain rate is relatively slow, the earlier waveform is retained and further amplified during the slower post-buckle deformation. This results from the phenomenon that an initial geometric perturbation is amplified into a fold, if the applied strain rate is very slow.