A New Formula for the Effect of Opening in Stiffness of Infilled Frames

Infills have positive and negative effects on structures. If designers ignore infills in designing, they probably confront problems such as over-designing in the main elements of structures due to not using the capacity of infill's stiffness and strength. Even problems like soft-story or short-column can appear during an earthquake. There are several equations for calculating the effects of the stiffness of infills. The article's, the purpose is that if there is an opening in the infills, the reduction factor in stiffness how will calculate. second, the present paper considers many parameters, which can be effective in the reduction factor, and few researchers consider them all together. Some parameters that are effective in reduction factors such as the location of the opening, area of the opening, the width of the opening, height of opening and frame section are considered. This is why more than 500 models are analyzed that each of them is different at least in one parameter with the other one. Therefore, based on these models run in the FEM environment, a new formula for calculating the reduction factor of stiffness in perforated infills is introduced. The new formula is more exact and more comprehensive than other formulas.

A New Formula for the Effect of Opening in Stiffness of Infilled Frames Keywords:

Infill , Opening , Finite Element Method , Reduction factor , Stiffness