Numerical Analysis Of Seismic Performance Of T-Shaped Steel-Concrete Composite Short Leg Shear Walls And Research On Its Bearing Capacity

The flexibility and diversity of the short leg shear walls makes it highly favored for engineering applications, and the T-shaped cross section is a common form of cross section in engineering. Steel-concrete short leg shear walls, a new form of embedded steel in short shear walls, which can effectively improve the seismic performance of the bearing capacity and ductility of short leg shear walls. Based on the randomness of earthquake action direction, the stress condition of short leg shear walls with T-shaped cross section is very complicated, and there are few literatures study the seismic performance of this kind of the short leg shear walls. Based on the results of the experimental study, the numerical analysis method is used to study the seismic behavior of the short leg shear walls in this paper.This paper uses finite element software DIANA to complete the numerical simulation analysis. The author selects suitable cracking model and constitutive relation by test parameters and boundary conditions and determines the suitable nonlinear analysis model and calculation methods of the specimens and establishes the nonlinear finite element analysis model of the T-shaped steel-concrete composite short leg shear walls under low cyclic loading. Secondly, based on the refined finite element model, the author analysis the influence of the variables tested of this type of shear walls, the variables tested include the loading direction, the axial load ratio, the shear span ratio and the form of reinforcement. The loading direction and the web symmetry axis direction are in the range of 0 degrees to 90 degrees and the loading direction is set at 10 degrees per additional a total of 10 angle direction, along with consideration of the three kinds of axial pressure ratio, two shear span ratios and two different form of reinforcement,90 bearing capacity of simulated specimens are calculated in total. The last but not the least, this paper based on experimental results and numerical analysis results studies the bearing capacity of normal section of T-shaped steel-concrete composite short leg shear walls and gives the calculation formula of bearing capacity with different loading direction. The following main conclusions were obtained:(1) The total strain rotating crack model in the smeared cracking model was selected to describe the cracking behavior of concrete, and the parabolic model was selected to describe the relationship of stress and strain of concrete in compression behavior, and linear model was chosen to describe the relationship of stress and strain of in tensile behavior, and folding two line and three line was respectively used as reinforcement and shape steel constitutive relationship, it can accurately simulated the hysteretic behavior of specimens under low cyclic loading, especially in the specimen damage accumulation and pinch effect.(2) Choosing the secant method as the iterative computation method can effectively avoid appearance of negative stiffness and can calculate the decline of the skeleton curve accurately.(3) When loading direction in the range of 0-60, the spacemens can maintain a high peak load, when the loading direction is over than 70 degrees, the peak load of specimens decreased significantly. The value of peak load in each direction is increased with the increase of axial compression ratio. The peak load is decreased with the increase of the shear span ratio. Shaped steel at the junction of the web and flange can significantly improve the peak load, especially in the range of 30-50 degrees.(4) The fitting calculation formula can calculate the carrying capacity of different loading direction, different shear span ratios and different axial compression ratios accurately.