Numerical Study of the Data Processing Methods in SHPB Experiments

Accurate measurement of the stresses and velocities at the boundaries of a dynamically loaded specimen may be obtained using split Hopkinson pressure bars (SHPB).However, the determination of a representative stress-strain curve based on these measurements can be challenging.According to the principle of SHPB technique, there are three groups of formulae to process the experimental data, and all the formulas are sensitive to time shifting.Due to transient effects and the error of time shifting, the stress-strain curves lack consistency.In order to solve the problem of time shifting, we introduce the three-wave mutual-checking method based on the conservation of momentum and the corresponding data processing program.It is shown that a more reliable stress-strain curve could be obtained using this method.In order to prove the correctness of this curve, numerical simulations of the SHPB experiments were performed.The results show that by using this program, the same result can be obtained by either the three-wave method or the two-wave method, and what matters more is that this method can avoid the error of time shifting which the traditional method cannot.