Enhancing performances of SHPB for determination of flow curves

A compression test on a Split Hopkinson Pressure Bar (SHPB) is the most common testing method adopted to determine material flowcurves in a quite wide range of high strain rates. However, in most ordinary SHPB applications material rheology can only be investigated up to a rather low strain. Furthermore, several phenomena, including friction at interfaces and radial and axial inertia, are potential sources of inaccuracy for flow stress data. The paper presents the main design-guidelines followed when developing a high-performanceSHPB system for the determination of accurate flowcurves. The results from hot compression tests carried out on Aluminium- and Nickel-alloys prove that with the developed system most of the limitations of ordinary-SHPBs are overcome and system performances significantly improve.