Two-wave methods and Three-wave method are conventional methods to process the SHPB experiment data. Due to the presence of transient waves in dynamic experiments, both the stress and strain fields within a specimen are seldom absolutely uniform. Different date processing methods lead to different results. In this paper, we have developed a program to compare the results getting from different methods. The difference of the strains corresponding to the ultimate stress can reach 20%. Which one is better? One material shouldn't have different constitutive. In order to solve the problem, we have developed Three-wave mutual-checking method, which is based on the conservation of the momentum of the whole system. This method provides a checking mechanism, so some human error can be avoided when process the same experiment data. By this method, different person can obtain the only credible stress-strain curve based on the same test data.

Evaluation of the dynamic properties of quasi-brittle materials is of the utmostimportance for assessing the vulnerability of structural components under dynamic loadingssuch as collision or explosion. To investigate the dynamic strength of (quasi)-brittlematerial, three-point bending tests are performed on a modified Split Hopkinson PressureBar. Such an apparatus is often used with pre-cracked specimen to determine the dynamicstress intensity factor of metallic materials. With quasi-brittle materials special carehas to be paid to the processing of the test since fracture can occur at very low strains.The specimen remains in an out-of equilibrium state and fracture occurs before the supportreactions appear as if it was a support-free impact test. A special non-equilibriumanalytical approach has been developed to process the tests. Finite-element simulationsare used to assess relevance of the proposed analysis for normalized short beams.Experimental results on brick and concrete samples showing a significant dynamic strengthincrease are presented.