Design And Study On The Flexural Performance Of Partially Encased Composite Beams

The partially encased composite structure is a new type of steel-concrete composite structure formed by welding steel bars or flat steel to form tie bars in the Hshaped steel web cavity and pouring concrete.Because of its advantages of good economy,fire resistance,no formwork,saving steel,etc.,the partially encased composite structure has received more and more attention.This paper uses the finite element analysis software ABAQUS to study the flexural performance of PEC beams and semi-PEC beams and completes the following work.(1)Based on the experimental research on the flexural performance of partially filled steel-concrete composite beams,the finite element analysis software ABAQUS is used to establish a finite element model of the partially filled steel-concrete beams,and numerical simulations are performed under low cycle reciprocating loads.Compared with the completed test results,the simulation results are in good agreement with the test results,which proves that the PEC beam finite element model established in this paper can accurately reflect its true force characteristics.(2)By analysising the influence of steel web thickness,steel flange thickness,concrete strength,steel strength,high-span ratio,and longitudinal steel bar on bearing capacity,energy consumption capacity,ductility and stiffness degradation,we can get some conclusions from the results.Firstly,increasing the thickness of steel web and flange has a small effect on the flexural bearing capacity of the PEC beam and the semiPEC beam;Secondly,increasing the strength of the steel and the high-span ratio has greatly improved the flexural bearing capacity of PEC beams and semi-PEC beams;In addition,the flexural bearing capacity of PEC beams and semi-PEC beams filled with concrete between the steel flanges has been greatly improved compared to the steel beams,but the strength level of the concrete has little effect on its flexural performance;longitudinal steel bars can effectively improve the distribution of concrete cracks and improve its flexural bearing capacity.(3)According to the analysis of existing PEC component tests and the previous parameter,the calculation method of the flexural bearing capacity is analyzed by using the superposition principle and the moment balance method.The results show that the force analysis method selected in this paper is more accurate.Based on this,the calculation formulas of ultimate flexural bearing capacity of PEC beams and semi-PEC beams are proposed.