No-linear Fem Analysis On No Diagonal Bars Small Span-to-depth Ratio Coupling Beams With PVA Fiber Reinforced Concrete

Coupled shear wall appear in high-rise building structure for actual need, the connecting link between wall limb is coupling beam, coupling beam is very important for high-rise building’s seismic resistant performance as this connecting link. It often be used as damper in shocking absorption and dissipating energy. It is easy to reach the seismic design requirement for coupling beams whose span-to-depth ratio is large enough, but for small span-to-depth ratio coupling beams who bear much more shear stress, it is not easy to reach the seismic design requirement. To solve the above problem, our team design a set of test and apply PVA fiber reinforced concrete which is developed by local concrete substrate of Shanxi and domestic fiber to making specimens instead of traditional concrete, PVA fiber reinforced concrete has high toughness and high elastic modulus. Test results is ideal, the performance of coupling beams with PVA fiber reinforced concrete is obviously better than coupling beams with traditional concrete.For a more in-depth study on coupling beam with PVA fiber reinforced concrete, the test is simulated by using non-linear finite element software ABAQUS, and the simulation results are compared with the test results. The feasibility of non-linear finite element modeling method is validated.A number of factors: span-to-depth ratio, section seize, stirrup ratio and reinforcement ratio are extracted, further by changing the finite element simulation parameters, the influence of those parameters on coupling beam be analyzed. The results show that:Firstly, small span-to-depth ration coupling beam’s bearing capacity could be improved through using PVA fiber reinforced concrete, and coupling beam’s ductility could also be improved. Under the premise of other factors being controlled, coupling beam’s bearing capacity reduces with the increasing of span-to-depth ratio, but it’s ductility improves gradually, the failure mode of small span-to-depth ratio coupling beam becomes bending-shear mode from initial shear mode for the increase of span-to-depth ratio.Secondly, with the increase of section width of coupling beam with PVA fiber reinforced concrete, coupling beam’s bearing capacity improves, but it’s ductility weakens.Thirdly, improving stirrup ratio could improve the bearing capacity of coupling beams with PVA fiber reinforced concrete, but when the stirrup ratio increases for 0.59%, there are little influence on coupling beams’ bearing capacity. The stirrup ratio’s influence on coupling beams’ ductility has the similar characteristic as the influence on bearing capacity, it is recommended that the stirrup ratio adopts around 0.6%.Lastly, with the reinforcement ratio’s increasing, coupling beam’s bearing capacity will increase, but the effect is not obvious. At the same time, coupling beams’ ductility has little improving. In the design of coupling beams with PVA fiber reinforced concrete, it is recommended that the reinforcement ratio adopts minimum ratio.Base on the truss-arch model and refer to shearing capacity formula of component with steel fiber reinforced concrete, the paper gives the shearing capacity formula of coupling beam with PVA fiber reinforced concrete, the calculated value is in good agreement with experimental value and simulation value.