Study On The Pulse Shaping Technique And A Programming Implementation For Data Processing Of The Hopkinson Bar Experiments

In this paper, the hybrid programming approach is used to compile a visual Hopkinson bar data processing program with VB and Fortran language. It is found that using a five-point based on least square method of smoothing cubic curve is feasible; In the process of aligning the three waves, the method that homogenized specimen stress or momentum conservation criteria should be used to check alignment of three-wave effect; The three-wave method should be adopted when calculating the project/true stress-strain relations and other mechanical results.Copper, brass, soft aluminum and steel are selected to carry out pulse shaping on free Hopkinson bar test. The test results of four different kinds of material are compared based on fulfilling not only the peak acceleration but also pulse duration closed to 100μs. when the pressure of 1.5MPa, diameter of 13mm and thickness of 1mm, the peak acceleration and pulse duration can be respectively reached to 104963g and 115μs:copper is a material which the original pulse show good consistency; the data consistency of soft Aluminum pulse shaping is not good.The numerical simulation on free and the split Hopkinson pressure bar technique is respectively conducted by means of ANSYS/LS-DYNA by choosing the appropriate arithmetic, element type, material constitutive model and the initial conditions. The results obtained from numerical simulation and experimental are in good agreement, thus it is demonstrated that simulation results are accurate and reliable.