Nonlinear Finite Element Analysis On Torsional Behavior Of Steel Reinforced Concrete Columns Under Combined Force

Steel reinforced concrete structure (SRC) is a kind of independent composite structure which embedded steel in reinforced concrete. Because of the composite effect, the SRC structure has the advantages of reinforced concrete and section steel. Compared with the reinforced concrete, the section of the SRC component is smaller. SRC structure has higher stiffness?better stability than section steel structure, and its fire resistance performance can be improved. With the social development, the require to appearance and functions of buildings is higher and higher. The increase of height and spa?diversity of appearance and complexity of structure makes the problems of torsion more and more obvious, which is urgent to be solved. Considering the advantages of SRC structure, the research on combined torsion should be focused on. These researches will improve the developments of high-rise building and long-span bridge in our country, and guarantee the safety, practicality and economical efficiency of structures. Meanwhile, these researches will fill the gaps of combined torsion design in SRC structural design code, and promote the development of SRC structure theory.The researches on torsion of SRC structure are complex, and the range of researches is wide. Based on the experiment completed, the paper make a preliminary study about the SRC structure performance of combined torsion and the theory of design calculation under monotonic loading using the simulation software ABAQUS. The main jobs have been finished as follows:1. Finite element models are established by nonlinear finite element analysis software ABAQUS according to the five groups of SRC columns. It aims to judge the feasibility of simulation through observing the failure process under combined torsion and getting the torsion-torque curve.2. Nine test parameters (such as axial compression ratio?torsion-bending ratio?shear span ratio etc.) have been analyzed to find the influence of failure and ductility under combined torsion.3. According to the experimental research and theoretical analysis, the formulas on cracking torque and peak torque under combined torsion have been put forward. The corresponding reduction factor also has been established through test data.