Author(s)

J. C. Li, X. W. Chen & G. Chen

Abstract

The adiabatic shear behaviour of a specimen is observed, based on a series of numerical simulations of SHPB test using 921A steel pure shear hat-shaped specimens in the present paper. The initiation and the propagation of an adiabatic shear band (ASB) and the relative distribution of temperature field in the specimen are analyzed. It is found that ASB is formed as the spread of an unstable zone with high temperature and high strain in the two ends of the Shear Zone. The spread speed of an ASB is related to the loading rate V0, whilst the width of ASB is nearly independent of the loading rate. All the ASBs are deformed bands corresponding to various values of V0. Keywords: SHPB, pure shear hat-shaped specimen, adiabatic shear deformation, numerical simulation. 1 Introduction Adiabatic shear deformation usually occurs in the high-speed deformations such as high-speed impact and penetration, etc. Adiabatic rising-temperature will lead the thermal softening effect and thus adiabatic shear band (ASB) occurs in the material. An ASB usually has a width of 10–100μm, in which the shear strain, shear strain rate and temperature can achieve a value of 1–102, 105–107s-1, and 102–103K, respectively. Meyers et al. [1] designed a pure shear hat-shaped specimen as shown in Figure 1, in which the Shear Zone deforms as a pure shear deformation when the specimen undergoes compressive loading. This hat-shaped structure has been used widely to study the adiabatic shear behaviour of material. Accompanied

Keywords

SHPB, pure shear hat-shaped specimen, adiabatic shear deformation, numerical simulation