Finite Element Analysis Of Torsional Stiffness On Steel Reinforced Concrete Members Subjected To Pure Torsion

Steel reinforced concrete structure is a new kind of composite structure,which can exert concrete’s and steel’s material behavior at the same time.Because of its good advantages of the large carrying capacity and the seismic behavior, steel reinforced concrete structure has been applied in engineering widely.In china,the research on torsion resistance of components starts relatively late and now there are few researches on torsion resistance of steel reinforced concrete. China’s relevant standards,like ‘Technical specification of steel reinforced concrete structures ’(YB9082-97) and ‘ Technical specification for steel reinforced concrete composite structures ’(JGJ138-2001) put forward the method and formula of calculation of the steel reinforced concrete under pure torsion.So it has important significance on the research of torsion resistance of steel reinforced concrete in a state of pure torsion.Based on the overall understanding of the experimental and theoretical studies of torsion in structural components,this paper does research on torsional stiffness of steel reinforced concrete in a state of pure torsion.This paper uses six components, including a reinforced concrete component and the others are all steel reinforced concrete components. Comparing reinforced concrete component with steel reinforced concrete, it is to study the influence of torsional stiffness of members whether they have steel or not. Analyses are conducted on the five steel reinforced concrete components when they are in case of the changing constraints of steel reinforced,concrete strength or steel reinforcement ratio.Simulating all components by the nonlinear finite element software ABAQUS,it is derived that the relationship of stress and strain of concrete,steel of steel reinforced concrete components in pure torsion which are under each typical analysis. And also it is well showed that the torsion resistance ability of steel reinforced concrete components in pure torsion.On the basis of the comparison of the torque- twist ratio curves of each component, the torsional rigidity of different parameters is analyzed.The torsional stiffness of steel reinforced concrete component can be idealized into three stages:elastic stage before cracking, after cracking to steel reinforced concrete components yield,After yielding to limit state.Based on refering to and combining the theory and method of calculation of torsional rigidity of reinforced concrete members and steel- concrete composite components,when steel reinforced concrete components crack,yield and are in limit state,it is derived that the calculation formula of torsional stiffness of them.By comparing the finite element value and the calculated value, the correctness of the formula is verified preliminarily.Finally, the research of this paper is summarized, and the problems of the research are presented.