Analysis Of Nonlinear Finite Element With Opening Infill Wall Frame Structure

The reinforced concrete frame structure with infill walls is a common structure that has been widely applied in the architecture. During the design of the structure, the designers usually design with the pure frame structure, in which they only concern the wall loading, but ignore the influence of the mechanical performance between the wall and its frame structure. In the practice, the holes have to be opened in the wall for the doors or the windows in the building. The opening with different sizes, shapes and positions should cause various degree of influence on the structure in different ways, i.e. the bearing capacity, deformation and the lateral stiffness of the structure, which makes the mechanical condition of the structure different with both the pure frame structure and the frame structure with infill walls.Firstly, the backgrounds, the importance of the study, and several common opening ways in the infill walls have been presented in this thesis. Then, the detailed description of the methods that was employed in this work has been given, such as the finite element model, the constitutive relation between the materials (concretes, steels and masonry materials). Finally, the ANSYS element that was applied in the work has been demonstrated, the one-story single-cross specimens of the structure with infill walls has been analyzed via stimulating, a good agreement between the stimulation and experiment has been reached.By using the ANSYS non-linear finite element, firstly we built the model for one-storey single-cross specimens of frame structure with opened infill walls, and then studied the influence of the bearing capacity, deformation and the lateral stiffness of the structure due to the shape, the ratio and the position of the opening under the horizontal loading in the model. And based on the former formula, by using the results of numerical analysis, propose a fitting formula of limit bearing capacity and the initial stiffness of opening window infill wall framed structure, meet certain accuracy. The thesis also through to build a series model, analyses the influence of the wall confinement effect and structure layer to the bearing capacity of the bottom structure. Moreover, the model of two-storey single-cross specimens of frame structure with infill walls was also constructed. The differences of bearing properties between the second above floor and bottom floor of the framework structure have been investigated with the different wall boundary conditions. Finally, based on the one-storey single-cross, by simulating the inverted-triangular loading distribution of each floor in the earthquake, nonlinear finite element analysis was used to study multilayer frame structure with the opening infill wall.At present, the studies on the mechanical properties of the frame structure with opening infill walls are still very limited both in China and abroad. Therefore, the study in this thesis should have certain theoretical and engineering significances.