The compression deformation mechanism of a metallic rubber

摘要

In this paper, the microcompression deformation mechanisms of a porous wire-like metallic body, designated metallic rubber, in uni-axial compression loading along the direction of cold stamping, have been investigated by conducting the macroscopic compressing tests and microscopic observation of the deformed material. The stress/strain relation suggest that the stress/strain relation curve could be divided into three distinct stages depending upon the variation in the stiffness with the compression deformation. The results which reveal that there exist different microscopic compression deformation mechanisms in each distinct stage: In the first stage, referred to as stage Ⅰ, the elastic deformation, owing to the elastic bending of each small segments of metallic wire, occurs in the body piece by piece. In the second stage, referred to as stage Ⅱ, the elastic deformation of all small segments of the metallic wire and crossed sliding friction operating in the contacted surfaces of the wire represent the main deformation mode of this stage. The third stage is the re-strengthening stage, referred to as stage Ⅲ. In this case, the deformation due to nonlinear elastic bending of a series of small segments of metallic wire coils and extruded sliding friction operating in the contacted surfaces of wire coils govern the behaviour of the metallic rubber.