Study On Mechanical Properties And Design Methods Of The Equivalent Replacement Reber Pre-Cast Concrete Coupling Beams

At present,the research on fabricated concrete structures mainly focuses on frame structures and shear wall structures.There are few studies on frame-shear wall structures(referred to as frame-shear structures),and the assembly of joint beams in frame-shear structures.There are fewer studies on methods.To this end,this paper proposes a new type of assembled concrete frame shear-structure shear wall coupling beam assembly and beam connection method,and the mechanical properties and design method of the concrete assembly beam are studied.Based on the finite element software WCOMD,the single-joint beam test piece and the double-joint beam test piece model were established respectively,and the finite element simulation analysis of the force-bearing process of the model under low-cycle reciprocating load was carried out.The simulation results are compared by the existing test results.The results show that the two have a good agreement,which proves the feasibility of using WCOMD software to simulate the stress process of the concrete assembled beam.According to the actual engineering dimensions and four influencing factors(is grouting strength,assembly area length,equivalent steel cross-sectional area ratio,and extension zone thickNess),10 single-joint beam specimens were designed.The finite element simulation method was used to simulate each The force-bearing process of the specimen under low-cycle reciprocating loads.By comparing and analyzing the influence of different influencing factors on the load-displacement skeleton curve of the fabricated single-joint beam,it can be seen that the bearing capacity and seismic energy dissipation capacity of the cast-in-situ single-jointed beam increase with the increase of the thickNess of the extended zone,and the ductility is reversed.The bearing capacity,seismic energy dissipation capacity and ductility of the assembled single coupling beam decrease with the increase of the thickNess of the expansion zone;the bearing capacity of the single coupling beam increases with the increase of the diameter of the equivalent generation of steel bars of the test piece,and the seismic energy dissipation The ability and ductility are reversed;the change of grouting strength and length in the assembly area has no significant effect on the bearing capacity,ductility and seismic energy dissipation capacity of the single coupling beam.According to the actual engineering size and five influencing factors(ie,beam-to-height ratio,grouting strength,assembly area length,equivalent steel cross-sectional area ratio,and extension area thickNess),12 double-joint beam specimens were designed,using the above finite element The simulation method simulates the force-bearing process of each test piece under low-cycle reciprocating load.By comparing and analyzing the influence of different influencing factors on the load-displacement skeleton curve of the fabricated double-jointed beam,it can be seen that the change of the thickNess of the extended zone has significant influence on the cast-in-place double-jointed beam test piece and the assembled double-jointed beam test piece;The bearing capacity of the cast test piece and the assembled test piece decreases with the increase of the span-to-height ratio of the coupling beam,and the ductility is reversed;the bearing capacity and ductility of the double-joint beam test piece increase with the diameter of the equivalent generation of steel in the coupling beam.The increase and the ductility and ductility of the double-jointed beam increase with the increase of the grouting strength in the assembly area.However,when the grouting strength is greater than 80 MPa.the influence on the bearing capacity of the double-jointed beam is no longer significant;The change of length has no significant effect on the bearing capacity,ductility and seismic energy dissipation capacity of the double-joint beam.Based on the research results of single and double beam specimens,the regression design method is used to summarize the simplified design calculation formula of the assembly beam.In order to verify whether the simplified design calculation formula can be effectively applied to the actual project,a cast-in-situ single-frame-shear structure will be designed with reference to the test cast-in-place test piece CC1 and related references,and then the simplified design calculation proposed in this paper is used.The cast-in-place coupling beam in the single-frame-shear structure was split and designed,and the finite element analysis software WCOMD was used for simulation analysis and comparison.It was found that the simplified design calculation formula can be effectively used in practical engineering.