Period formula for RC frame buildings considering infill wall thickness and elasticity modulus

Abstract

Estimation of a proper fundamental vibration period is an important issue in the process of the design and/or evaluation of a building. Mostly, infill walls are assumed nonstructural elements which are ignored in the estimation of the vibration period of a building in terms of stiffness. However, studies showed that infill wall has significant effect on vibration period and should be considered in the estimation of period. Even infill walls are considered by some proposed equations in the estimation of period, they do not consider the effect of infill wall stiffness. In this study, an empirical equation is proposed as a function of building height, elasticity modulus of infill wall, and thickness of infill wall. For this purpose, building periods were determined with considering different infill wall elasticity moduli, infill wall thicknesses (thus, different infill wall stiffness), and building heights. Nonlinear regression analyses were conducted with a comprehensive statistical study. Effect of elasticity modulus and thickness of infill wall on vibration period was investigated. Finally, comparisons between the proposed equation of this study and those of previous studies were conducted.