Uniaxial compressive performance of an aramid and aluminum honeycomb sandwich structure

Abstract

In recent years, explosion and impact resistance capacity of composite sandwich structures has been widely studied. However, the study of their basic mechanical properties is still lacking, which severely hinders the application of composite sandwich structures. This paper focuses on uniaxial compressive performance of a sandwich structure, so as to provide design guidance and promote application of such structures. Firstly, a novel aramid and aluminum honeycomb sandwich structure is proposed for explosion and impact resistance. Secondly, experimental and numerical studies on uniaxial compressive performance of the structure were conducted. Seven indices including yield compressive load were introduced to assess compressive behavior of the structure. A simulation framework to predict load-carrying capacity of the structure is proposed, in which the complex aluminum honeycomb was modeled as a cube with equivalent material properties. The mechanism of how the structure collapses under uniaxial compressive load was revealed. Thirdly, parametric sensitivity analysis was conducted. According to experimental and calculated results, the structure approximately undergoes five stages under progressive compression: uniform shrinkage in vertical direction, yielding at local regions of the weaker panel (rear panel), plastic deformation development on the rear panel, overall bending of the whole specimen, and fracture of localized welds. Front panel thickness and initial imperfection have little influence on compressive behavior of the structure, while thickness of the weaker panel (rear panel) is the decisive factor of compressive load-carrying capacity. Yield load, yield displacement, ultimate load, and elastic stiffness increase linearly with the increase of rear panel (316L) thickness, while ductility coefficient decreases linearly with the increase of rear panel (316L) thickness.