Data Acquisition And Data Processing Designation Of The Hopkinson Bar Experiments

Based on the literature exploration, the developments of Split-Hopkinson Pressure Bar (SHPB) techniques and its principles are introduced in this paper.in the present paper, an application of data acquisition by GPIB in the Hopkinson Bar experiments is provided. Two programs named test.c and testl.c for acquiring wave data from TEKTRONIX 2440 oscilloscope and LECROY 9370 oscilloscope by GPIB are presented in this paper, respectively.A data processing program for SHPB experiments is setup to enhance efficiency of data processing. During the processing, there is only a start point of input strain that needs to find. The start points of output strain and reflect strain can be got by calculating propagation time of elastic wave through the bars. The first-step result can be checked up whether the result is validity, that is, three strain curves can be drawn on screen to determine the start point of the curves. Strain-time, stress-time, strain-rate-time, strain-stress curves can be finally obtained. After all, the help file and explanation is provided in the program.To check up the validity of the processing program, 18 groups of experimental data are provided. The 18 experimental data were processed by hand and by the program, respectively. The comparison between the results comes to a conclusion that the program is trustworthy. In order to proof the program's effectiveness, we made some experiments on LY-12A1 by SHPB.In addition, based on the Pochhammer-Chree's theoretical solution about the stress wave propagation in infinite cylindrical bar, a numerical approach for analyzing dispersion in SHPB experiments is developed.