The Influences Of Infill Wall On Natural Period Of Multilayer Rc Frame Structure

Infill wall frame structure because of its advantages of space layout is more agile is widely used in office buildings, schools, shopping malls and residential, is China’s more than one of the structure of the more common form of high-rise buildings. Lots of experimental study and theoretical analysis show that the filler wall effect on the natural vibration period of frame structure can’t be ignored, this article mainly from the filler wall masonry materials and space layout are two major factors to consider filling wall effect on the natural vibration period of frame structure, main work is as follows:1) based on the framework of structural natural vibration period of the theoretical calculation method and based on the structural dynamic characteristic test of the summary of the experience formula, it is concluded that considering the experience formula of the filling wall masonry materials and space layout, and simplified model based on the existing common filler wall were analyzed, points out the scope of the use of the simplified model and finite element model used in this paper.2) with finite element software ANSYS based on the actual engineering example to set up a four layer reinforced concrete frame structure, based on the different filler wall masonry materials and space layout to establish finite element model for modal analysis, and introduce new parameters χcycle correction coefficient, this parameter can correspond to structure dynamic characteristics of the measured data, can better were analyzed. Results showed that the four different modulus of elasticity in masonry material changes impact on the natural cycle of the infilled wall frame structure; Space arrangement in the horizontal direction should be uniform layout, vertical uneven arrangement of filler wall in weak layer of the filling rate and the number of weak layer’s floor had a great influence on free vibration period of filler wall. And through a single considering the influence of filler wall quality and stiffness were analyzed.3) Through the three multi-storey reinforced concrete frame structure (pure infill frame structure and frame structure) twice structural dynamic characteristics of the test, and by considering the infill wall stiffness and rigidity without considering filling two ways to build a finite element model, and were drawn cycles and cycle reduction factor correction factor, hoping to establish a relationship cycle reduction coefficient and cycle correction coefficient in order to better apply to the actual project. And our empirical formula used in conjunction with the measurement cycle infill frame structure and the relative ratio of the theoretical cycle, and pointed out the empirical formula can be used in multi-storey reinforced concrete frame structure.