Impact Behavior and High-Energy Absorbing Materials

Abstract

Impact behaviors of structures are gaining more research attention due to increasing demand for designing structures under extreme loading. At the same time, effective protection of structures from low-velocity impact and blast loading and the development of various high-energy absorbing materials as well as strengthening and retrofit-hardening techniques for conventional materials and structures are also of contemporary interest. This special issue on “Impact Behavior and High-Energy Absorbing Materials” is the second part of a two-issue series July Qiao and Binienda 2008 and October the present issue 2008 . It provides a comprehensive survey of theoretical, computational, and experimental investigations of impact mechanics and highenergy absorbing materials. The issue begins with a review paper, followed by papers on several relevant topics. These range from impact response of prestressed composite laminates to indentation behavior of sandwich structures, dynamic enhancement mechanism of metallic hollow sphere material, full-scale blast test of a masonry structure retrofitted with fiber-reinforced polymer composites, experimental characterization of residual tensile strength of woven graphite epoxy laminates due to low-velocity impact, and concrete confined by a prefabricated composite jacket for potential impact protection. Qiao, Yang, and Bobaru provide a comprehensive review of the theoretical, computational, and experimental study of impact mechanics and high-energy absorbing materials. Different theoretical models rigid-body dynamics, elastic, shock, and plastic wave propagation, and nonclassical or nonlocal models and computational methods finite-element, finite-difference, and meshfree methods used in impact mechanics are reviewed and discussed. In particular, some recent developments in numerical simulation of impact e.g., peridynamics and new design concepts proposed as high-energy absorbing materials lattice and truss structures, hybrid sandwich composites, metal foams, magneto-rheological-MR-fluids, porous shape memory alloys are emphasized. Recent studies on experimental evaluation and constitutive modeling of strain-rate-dependent polymer matrix composites, for example, are also presented in some papers in this special issue. The review is intended to help readers in identifying starting points for research in modeling and simulation of impact problems and in designing energy-absorbing-materials and structures. Using Fourier series expansion and Laplace transform, Zheng and Binienda obtained an analytical solution for the impact response of a simply supported laminated composite plate under prestresses, in which a linearized elastoplastic contact law was adopted when considering permanent indentation during impact.