The Influence Of Pre-crack Location On The Dynamic Failure Of Concrete-like Brittle Heterogeneous Material

Concrete-like heterogeneous brittle material is working with cracks, whose failureprocess is micro-cracks initiation，propagation and coalescence. The preliminary states ofcracks affect final failure modes, strength and mechanism. In engineering structure, thelocation and angle of cracks show a random distribution, which are uncertain.Comprehensive understanding of crack states is very important for engineering design andfailure process. So, it is important to fully understand the influence of pre-crack set indifferent locations on crack evolution and failure modes.Based on that, in this paper, it is focused on damage evolution mechanism andregularity of concrete material with a pre-crack set in different locations, expecially on theresearch in meso-scopic pattern dynamic evolution that induces the characteristics ofstress redistribution, strength change, ultimate strain and energy dissipation.A numerical simulation and analytical investigation into two-dimensionalpre-crack models under dynamic uniaxial compression is presented. Simulation model wascarried out on concrete material, each with a single horizontal crack that was located inedge, quarter and center accordingly.In this paper, a numerical simulation and analytical investigation into pre-crackmodels that are edge pre-crack model, quarter pre-crack model and center pre-crack model,under dynamic uniaxial compression is presented. Simulation model was carried out onconcrete material, each with a single horizontal crack that was located in edge, quarter andcenter accordingly. Comparative results were described on compressive failurecharacteristics of different pre-crack samples, and the influence of pre-crack location onfailure and meso-scopic mechanism were researched. Damage micro pattern dynamicevolution processes and features of pre-crack samples were presented. The relationbetween the damage evolution and stress redistribution was analyzed. The study showsthat existence of pre-crack reduces the strength, ultimate strain value, elasticity modulusand lifetime etc. And the more the pre-crack is close to center, the more easily and thelower the strength is. The nearer the pre-crack is close to edge, the more unstable the crack propagation is. The location of pre-crack affects the final failure mode. However theinherent mechanism is that the distribution of pre-crack results in different damage patternevolution.