The Influence Of Infilled Walls On Dynamic Effect Of Frame Structure And Design Strategies

In building structure, frame structure system is one of the most widely used structure form. This form is widely used because of the following reasons:First. The whole concrete frame lias strong integrity, good rigidity and good anti-seismic effect; Second, The frame column and beams can be design into different section forms, not only practical but also beautiful; Third. The weight of filled wall is more and more light.which induces the weight of frame structure:Fourth, frame structure can be flexibly divided space, which can be better cooperate with construction layout.Over the years,they are many reports on the earthquake damage in the structure of the framework all over the world. These reports indicate that the filler wall of frame structure first damage and then structural components are damaged. Structural damage can result in the failure of the whole structure. This result is caused by many reasons, mainly from the following aspects of structure design. At present, because of the limit of computer technology, engineers usually use pure framework model, which is used to simplified analysis. Then the corresponding adjustment according to the specification, finally draw the construction drawings. Pure frame structure natural period of vibration reduction is based on "the relevant provisions of JGJ32010or higher.""regulation" GB50011-2010. First of all, this simplified method ignores the effect of infilled walls on the structural bearing capacity. Secondly, this simplified method ignores the effect of infilled wall fixed effects on the structure stiffness and structure.From a practical point of view, although this method is simple, easy to implement, but there are also some uncertainty. Because the specification is given of the structure natural period of vibration reduction coefficient is a range of values. There is no solution for the given different wall materials, wall density, building the actual situation specific specification. This resulted in the design process of specific project, project managers need to rely on experience to determine the natural period of vibration reduction coefficients of concrete. After analysis, we can obtain a multi-storey frame structure, when the cycle reduction coefficient decreases0.1, calculation of seismic force structure will increase about10%. If the designer due to lack of design experience using the periodic folded improper reduction coefficient, will lead to structural design results unsafe.In view of this, this article conducts the research to the seismic effect of infilled wall frame structure. In this paper, the authors use the finite element software ANSYS10.0. SHELL63element is adopted to the actual density, elastic modulus, thickness, arrangement form of filling wall simulation. The establishment of various infilled frame model, using dynamic time-history earthquake analysis of each model method. The main contents of this paper include the following aspects:(1) Study in seismic calculation and is not involved in the seismic effect on all aspects of the seismic performance of infill wall. Considering the effect of infill walls, the natural period of structure stiffness increase, decrease, floor displacement decreased significantly, von Mises equivalent stress and strain decreases. Suggestion:in structure design, we should consider the contribution in the earthquake according to the filling wall;(2) When a weak layer in the bottom frame structure, the pure frame structure and no weak layer filled wall structure seismic performance comparison. By comparison:infilled walls along the vertical uniformly distributed structure stiffness increases, decreases the vibration cycle, the equivalent stress decreases, the equivalent strain decreases. Whether the population along the height direction of the uniform wall floor layout on torsional periodic structure is larger.Suggestion:we should adjust the floor stiffness, avoid stiffness mutation. Because the function demand of the building can not be avoided, we should take measures such as strengthening;(3) On the wall filled with different opening rate, we performed comparative analysis on seismic performance of structure:With the increase of the ratio of holes, the stiffness of the structure is small, floor displacement increases, von Mises equivalent strain increase structure, the equivalent stress increases, the seismic unfavorable. Suggestion:in order to meet the lighting requirement, try to open a small hole, We can increase the relevant provisions in this respect.(4) Frame structure with different filling materials, we performed comparative analysis of various aspects of the seismic performance of structure:when the filling material elastic modulus are roughly equal, density decreases, the structure frequency increases, the cycle is reduced, the structure displacement decreases, the equivalent stress and strain are reduced, the structure more safe, more conducive to earthquake; When the filling wall material density is close, the elastic modulus decreases.the structure frequency decreases, structural displacement increases, the structure of equivalent stress and equivalent strain are increased, structure is not safe, the seismic unfavorable. Suggestion:the structural design and architectural design personnel should be prepared to coordinate the work of communication. To meet the function demand of the building must also ensure structural coordination and good seismic performance.