Numerical Simulation Of Mechanical Properties And Microscopic Structure Of The Polypropylene Fiber Concrete

At present, polypropylene fiber concrete(PFC) has been widely used at home and abroad,but the study on mechanical properties of PFC is largely confined to the experiments. Theycannot satisfy the practical needs, therefore, it needs to use a numerical simulation technologyfor research.In this paper, PFC is the multiphase composite materials uniform properties. It is takenas multiphase composites consisting of coarse aggregate, fiber, Cement mortar matrix,aggregate - mortar contact surface and fiber - mortar contact surface. The number of coarseaggregate and polypropylene fiber are figured out by Walraven formula within 2d, and usingthe monte-carlo method and finite element software ANSYS to generate random aggregatemodel. Then carrying on the finite element mesh division and giving the corresponding unitof different materials properties, getting the"numerical specimens". Finally take numericalsimulation test on specimens of PFC by finite element software ANSYS.This paper has analysed the failure process of random aggregate model of PFC atuniaxial compression and splitting tensile conditions. The results can meet the failure processof macro structural components. It proofs that the compressive strength of low rate PFC allhave a certain degree improvement, but the effect is not obvious. This result also shows thatthe toughness of PFC is strengthened, and its damage get delays .Taking the numerical simulation of random aggregate model at the uniaxial compressivecondition and the Composite effective elastic modulus method as theories, this article hasComputed static compressive elastic modulus of PFC, and also estimated elastic modulus offiber - mortar transition layers by the method of mesoscopic simulation.According to the mesoscopic structure of PFC and the numerical calculationperformance of concrete, the paper has built the relationship between macro characteristic andmesoscopic structure of concrete by the computer simulation technology,and has alsoresearched the role of fiber in PFC. The results has a certain directive significance for theresearching mechanism and engineering application of PFC.