Hardness is often used to characterize the ability of a material to resist indentation deformation, and to reflect the yield strength, strain hardening ability or bond strength between atoms. The traditional hardness measurement technology can effectively reflect the mechanical properties of materials in quasi-static process, but the existing research shows that the plastic deformation behavior of most materials is strain rate dependent, and the yield stress of most metals increases at high strain rate;

The fracture toughness and fracture strength of ceramics will also be improved due to the strain rate effect. Therefore, the static hardness can not reflect the high strain rate behavior of the material in high-speed cutting or high-speed impact. The dynamic indentation is formed on the surface of the sample by the stress pulse acting on the rigid indenter contacting with the sample, and then the dynamic indentation hardness of the material is measured. The dynamic hardness reflects the ability of the material to resist the dynamic indentation deformation of the indenter, and the strain rate reaches 10 ~ 104 / s. at the same time, the dynamic hardness test is fast and convenient, and the sample is not damaged. Therefore, dynamic hardness is an important parameter to reflect the high strain rate behavior of materials under complex triaxial stress conditions, and it is expected to become a new method to evaluate the dynamic properties of materials. 

Based on the traditional SHPB device and the principle of single stress pulse loading, a new dynamic hardness testing system is established. Its structure is shown in Fig. 1. The system consists of single stress pulse generator, waveform shaper, pressure head, signal acquisition device and data processing device..

Equipment function introduction and main technical indexes:
   Alt1000 super dynamic data acquisition system is specially used for the test and analysis of Hopkinson pole experiment. The system has a transient maximum sampling rate of 40MHz, each channel is independent a/d analog-to-digital converter, and the external strain conditioner completes the stress and strain test and analysis of 1 / 4 bridge, half bridge and full bridge state. It has the functions of automatic test control and data waveform analysis and processing for real-time acquisition, real-time display, real-time storage and real-time analysis of the measured signal.