Numerical Analysis Of Impact Resistance Of Reinforced Concrete Composite Beams

In recent years,my country is vigorously promoting the industrialization of construction,and prefabricated buildings are the development direction of future buildings.The prefabricated monolithic building has good overall performance and seismic performance,and is a widely used and mature structural system at the current stage.Laminated components are the basic components of prefabricated monolithic buildings,mainly including laminated beams and laminated slabs.As an important horizontal force-bearing member in an assembled monolithic structure,the force-bearing performance of the composite beam is a hot research topic at present.The research on composite beams at home and abroad mainly focuses on the static performance and seismic performance,and there are relatively few studies on the dynamic performance under impact load.Therefore,it has important theoretical significance and practical value to carry out research on the impact resistance of reinforced concrete composite beams.In this paper,the reinforced concrete composite beam is taken as the object,and its impact resistance performance is studied by the finite element simulation method.The main research work is as follows:(1)Using ANSYS/LS-DYNA finite element software,the finite element simulation of the drop weight impact test of reinforced concrete composite beams,reinforced concrete beams and CFRP reinforced beams in the existing literature is carried out.The simulation and test results are compared and analyzed from three aspects of the time history curve.The simulation results are in good agreement with the test,which verifies the validity of the finite element model and parameters,and lays a foundation for further research on the factors affecting the impact resistance of composite beams.(2)Using ANSYS/LS-DYNA finite element software,the dynamic response and failure process of reinforced concrete composite beams with different design parameters and impact parameters under impact load were numerically simulated.The effect of parameters such as reinforcement ratio,hoop ratio,span-to-height ratio,superimposed layer height ratio,boundary conditions,drop weight,impact velocity,hammer head shape,cushion block material and thickness on the impact resistance of reinforced concrete composite beams was studied.Numerical simulations were carried out on the dynamic response and failure process of damaged composite beams with different CFRP reinforcement parameters under impact load,the influence of parameters such as the reinforcement spacing of CFRP strips and the number of pasting layers on the impact resistance of damaged composite beams was analyzed.This provides data support for the further research on impact resistance design methods and suggestions of reinforced concrete composite beams.(3)Referring to the impact resistance design method of reinforced concrete cast-in-place beams in the existing literature,through statistical analysis of displacement data of reinforced concrete composite beams and CFRP-reinforced damaged beams under different impact conditions simulated by finite element analysis,the empirical formulas for predicting the peak displacement and residual displacement of composite beams and CFRP-strengthened damaged beams under impact load are fitted.Using the empirical formula,the peak displacement or residual displacement of the composite beam can be quickly predicted when the static bearing capacity and impact energy of the composite beam are known,providing a reference for the impact resistance design of composite beams.On this basis,according to the research results of the influencing factors of the composite beam’s impact resistance,the impact resistance design suggestions of the composite beam are put forward.