Effects of nonhomogeneity, cell damage and strain-rate on impact crushing of a strain-softening cellular chain

Abstract

The effects of a systematic spatial variation in properties (nonhomogeneity), cell damage and strain-rate on the gross deformation of a cellular system subjected to impact are examined via a one-dimensional model of masses interconnected by strain-softening structural links. Damage initiation, propagation and distribution in the mass-link chain and the deceleration imposed on the colliding body are studied. Results show that damaged cells decrease the energy absorption capacity while rate sensitivity exerts an opposing stabilizing influence by spatially distributing deformation more evenly and smoothing out fluctuations in the resisting force of the system. Variation in cell mass and compliance along the chain strongly affect damage patterns and promote localization of crushing in the vicinity of weaker cells. These findings have implications on cellular systems such as crushable polymeric foams. © 1992 Pergamon Press Ltd.