The Study On Torsional Stiffness And Deformation Of Steel Reinforced Concrete Combined Torsion

Steel reinforced concrete structure as a new type of composite has been widely used in engineering with its advantages of high load capacity, deformation capacity, durability and fire resistance. In building structure, the components are in many cases subjected to torsion, but in few cases under pure torsion. Most are subjected to combined torsion under the interaction among pressure, bending moment, shear force, and torque. Torsion effect is one of the most important factors that cause earthquake damage to buildings. At present, the relevant calculation methods and formulas of the steel reinforced concrete component under the effect of combined torsion were not proposed in Chinese relevant standards of"Technical Specification of steel reinforced Concrete Structures"(YB9082-97) and"Technical Specification for steel reinforced Concrete Composite Structures"(JGJ138-2001). Therefore, carrying out the study on the torsional behaviors of the steel reinforced concrete combined force component and the calculation methods is very urgent.The research on steel reinforced concrete component was made through the following aspects in this paper:(1) Comparative verification test of ANSYS finite element was carried out on three steel reinforced concrete components tested by National Central University in Taiwan. Under the same condition of component size, the type of steel model and the reinforcement, etc., simulated the whole process from loading on the components to break, and finally obtained the stress situations of the concrete, steel, reinforced stress situations and the curve of torque-torsion angle, which would be used to compare with the experimental analysis conclusions.(2) Analyze eight H steel reinforced concrete components under the effect of combined force of pressure, bending moment, shear force and torque, while observing the effects on component stiffness and deformation properties caused by various factors, mainly including the axial compression ratio, the section of component, the concrete strength and the reinforcement ratio. Then the limit torque of components, cracking torque and the curve of torque-torsion angle can be obtained to make sure the influence rules of those factors.(3) Analyze eight steel reinforced concrete components with a hollow rectangular steel tube each under the situation of combined torsion as well as the effect on component stiffness and deformation properties influenced by the axial compression ratio, the section of component, the concrete strength and the reinforcement ratio. Then the limit torque of components, cracking torque and the curve of torque-torsion angle can be obtained to make sure the influence rules of those factors.(4)The mechanical properties of the component composed by two kinds of steel were comparatively analyzed. Calculation formulas to torsion stiffness and deformation of H steel reinforced concrete component and steel reinforced concrete component with a hollow rectangular steel tube under the situation of combined force of pressure, bending, shear, torsion was proposed according to the calculated data and conclusions and combining with the torsion theory.