A Study of the Dynamic Plane Strain Fracture Toughness of Concrete by SHPB

摘要

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 K_(IC) and K_(Id) 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 K_(Id) can be determined. By comparing K_(Ic) and K_(Id) we could conclude the result which meant concrete was more liable to crack under dynamic load.