Numerical Simulation On The Size Effect Of The Compressive Strength And Fracture Parameters Of Concrete

Size effect is very important to the mechanical property of concrete, and it directlyinfluences the evaluation of true strength, carrying ability and the durability of structure ofconcrete. Researching mechanical parameter of concrete material is affected by the sizechange such as intensity, fracture energy, stress intensity factor and J-integral. So it hascrucial theoretical and engineering significance to the study of concrete material.According to the numerical simulation of car crash reinforced concrete guardrailcoupled systems based on the plastic damage constitutive model by the software ABAQUSto research the dynamic response curves analysis of reinforced concrete guardrail indifferent speed and different impact angles. The feasibility of plastic damage constitutivemodel was verified and then the size effect existing in compressive strength of differentsizes of concrete cube, prism and test cylinder of different sizes and different heigh wassimulated and analysis with experimental results. The size effect of concrete fractureenergy of three point bending beam of incision in different size, different height, differentseam height ratio and different span was simulated by using the cohesive elementtechnology and analysis with the experimental results. Calculating the stress intensityfactor and J-integral of three point bending beam of incision in different seam height ratio,different load, different radius of the crack tip by contour integral and analyse therelationship with the size of the specimen.According to the numerical analysis and experimental results, the following thingscan be known: the simulation analysis of concrete compression strength based on theplastic damage constitutive model is feasible, and it is concluded that the concretecompressive strength exists size effect. Application unit based on traction separation ruleto analyse the concrete fracture energy is feasible, and it is concluded that the size effectexists in the concrete fracture energy. Contour integral technique used in calculating stressintensity factor and J integral value is feasible, and analyse the relationship with the size ofthe specimen under different working condition. The results show that the influence of size effect should be considered during the research of mechanical properties in concretecompressive strength and fracture parameters.