Papers by Keyword: Hopkinson Press Bar

Abstract: Concrete is a type of engineering composites which is widely used in military and civil structures. The static performance of concrete can not be used to estimate the variation of concrete under high strain rates under dynamic loads. By introducing the three point bending test under static and dynamic loads, the plane strain fracture toughness KIC and KId were measured. Using the application of experimental-numerical method a three-dimensional model has been established by FEM software Ansys/LS-DYNA, to carryout transient analysis, and the response curves of stress intensity factor-time through the opening displacement of fracture. Thus, with obtaining the cracking time by the method of strain-gauge, the dynamic plane strain fracture toughness KId can be determined. By comparing KIc and KId we could conclude the result which meant concrete was more liable to crack under dynamic load.

Abstract: When the KId (dynamic fracture toughness) of the three point bending components is tested on the SHPB device, the signals of reflected waves obtained have been elongated because the end of the incidence pole is generally made by wedge shape. Through the conduction theory based on one dimension stress wave theory, the reflection and transmission phenomena of waves on the surface of the wedge have been analyzed. In the present paper, the loads acting the components have been modified, by removing the stress wave part among incidence and reflection waves reflected by the wedge surface.