Mechanical Properties Simulation Of Steel Fiber Reinforced Lightweight Aggregate Concrete Beam-slab-column By Discrete Element Method

In order to study the mechanical properties of steel fiber reinforced lightweight aggregate concrete,this study establishes discrete element model which basically conforms to steel fiber light aggregate concrete mechanical properties,and verifies the bending and shearing failure form and process of beam with the help of discrete element method basing on discrete particle displaced metaprogramming.After summarization of characteristics of the model,the model was applied to the plate and the column plate of the punching and column pressure simulation analysis.The main research is as follows:Establishment of particles of different granule can form particles in different shapes.Various particles mixing together will form initial raw material model of the steel fiber,lightweight aggregate,concrete particles.Particles in the program settings in the different stages of the simulation of different physical properties obtained at different stages of the results and improve the computational efficiency.In the model of bond parameters,unit to stiffness,unit shear stiffness,critical method to stress and bond radius are four parameters which have significant influence on the peak force of simulation test block.The setting of critical shear could avoid particles bonding points from being cut off too early.The five parameters above is key factor of establishing real simulation model in the discrete element method.After parameter calibration,and being compared with real test data,the model of beam test and the beam test parameters were finally determined.There are certain similarities between bending and shear failure simulation established on various fiber volume ratios and different sizes of beam model,,and the true test form.The development and deformation and failure process of the loading crack which is difficult to be observed by the real test are obtained.According to the basic mechanical parameters,different sizes of plate and column models are established.Through numerical simulations and experimental research results,this paper found out :1.concrete with steel fiber added can increase the ductility,with the increasement of steel fiber volume ratio,increase deformation before failure of the components;2.The different shear span ratio of beam shear failure morphology are different;the incorporation of fiber,plate thickness increased can improve the plate of punching shear bearing capacity of;3.short column in the failure of shear slip,long column failure will bend.The results of research of the steel fiber reinforced lightweight aggregate concrete provide a reference.