Seismic Performance Test And Nonlinear Finite Element Analysis Of Prefabricated Steel Reinforced Concrete Composite Beams

Prefabricated steel reinforced concrete composite beam?PSRC?is a product of combining steel reinforced concrete structure with prefabricated concrete structure.Because the section steel in the structure has not only made up for the disadvantage of poor seismic performance of prefabricated assembly structure,but also has the advantages of simple construction procedure of prefabricated concrete structure.Therefore,prefabricated steel reinforced concrete composite beams are increasingly widely used in today's social building structures,especially for long-span,heavy-duty structures,prefabricated steel reinforced concrete composite beams play a more obvious advantage.However,there are few studies on the seismic performance of PSRC beams under different parameters.Therefore,a total of 36 PSRC beam specimens have been designed.As 17 of them have been tested by the last brother,the remaining 19specimens will be tested under cyclic loading in this paper.By recording the changes of cracks and deformations of specimens under loading,and from the angles of load-displacement curve,skeleton curve,energy consumption,ductility coefficient and stiffness degradation curve^[1-2],the effects of factors such as whether the cast-in-place structure is lightweight aggregate concrete,pouring mode,whether there are shear connectors and section steel types on the seismic performance of PSRC beams are studied.The software ABAQUS is used to model and analyze 18specimens of beams with full consideration of material non-linearity,geometric non-linearity and contact non-linearity.The results show that the model can accurately simulate the mechanical behavior of actual members to a certain extent,and it is feasible in a certain range.On the basis of this model,four design parameters,namely,the length of shear connectors,the spacing of shear connectors along the length direction of beams,the expansion ratio of honeycomb steel and the pass of honeycomb steel,are selected,and the effects of parameters on the mechanical properties of PSRC beams are studied under different parameter levels.The conclusions are as follows:?1?The viscous damping coefficient of PSRC beams under cyclic reciprocating loads is larger than that of ordinary concrete beams and larger than that of ordinary steel reinforced concrete beams,which shows that PSRC structures have good seismic performance.?2?The effect of shear span ratio on seismic performance of PSRC beams is more obvious.The smaller the shear span ratio,the greater the possibility of brittle failure.The ductility and energy dissipation capacity of specimens with large shear span ratio are improved,and the bearing capacity of specimens with smaller shear span ratio is decreased.The shear connectors and honeycomb steel have improved the bearing capacity of PSRC beams,and the ductility and energy consumption have decreased in the later stage.Casting type and cast-in-situ concrete type have little influence on seismic performance of PSRC beams.?3?The load-displacement curves obtained by ABAQUS software are in good agreement with the experimental results,which preliminarily verifies the rationality of the model;and the failure characteristics of the two models are in good agreement with the analysis of the experimental phenomena by cloud analysis,which shows that the model can meet certain engineering needs.?4?The analysis of design parameters shows that the length of shear connectors and the spacing of shear connectors along the beam length have little influence on the mechanical properties of PSRC beams,and the expansion ratio and pass of honeycomb steel have some influence on the mechanical properties of PSRC beams.