Study On Flexural Behavior Of The Composite Beams With Opening Web-encased Concrete Section

The opening web-encased steel-concrete composite beam is developed with the basis of the investigation and application of steel-concrete composite beam and steel reinfored concrete beam.Its main constitution way is that the stirrup are penetrated into the web,up flange and web reinforcement arrangement around the longitudinal distribution,binding the distributing reinforcements to a cage and then pouring concrete with all,which forms web-encased steel-concrete composite beam.Comparing with the traditional steel-concrete composite beam and reinforced concrete beam,the beam has lots of merits,such as higher supporting capacity,ductility,stability and safe margin,also has the construction craft,a well fire protection performance,higher overall performance target.Using the finite element analysis software ABAQUS,the flexural behavior of composite beams with opening web-encased concrete section was studied in this paper.The main works are as follows:(1)By comparative analysis on the result of existing test,the validity and applicability of the model about composite beams with opening web-encased concrete section base on the concrete damaged plastic model of ABAQUS is verified.(2)Loading a total of 9 composite beams with opening web-encased concrete section including round,hexagonal,rectangular hole respectively using three-point vertical static load,to study the failure pattern and failure mechanism with monotonic loading,then analyzes the bearing capacity of composite beams with the influence of different groove and hole density.(3)The best value range is obtained by changing the cross ratio,aspect ratio,etc of the composite beam.Some factors such as web height,width,thickness of bottom flange and the concrete strength,which maybe impact on the bearing capacity of composite beams with opening web-encased concrete section are studied.(4)Based on the plastic design method,the formula for calculating the bending capacities of composite beams with opening web-encased concrete section are proposed,which can be used to composite beams in full shear connection.