Infill Panels: Their Influence on Seismic Response of Buildings

摘要

Infilled frame structural systems, wherein conventional frames are filled, in their plane, with construction, have consistently performed poorly in past earthquakes yet frame-infill systems continue to be used throughout the world as they provide an economic means to enclose and partition space that suits many local building traditions. There is, therefore, a clear need to develop methods to predict the behavior of frame-infill systems to anticipate undesirable behavior and take measures to avoid it. This study poses an answer to this need. The problem of modeling the stiffness contribution of infill panels to elastic frame-infill systems is discussed. A set of dimensionless parameters is developed that is sufficient to define the nature of this stiffness contribution. A means to model the structural behavior of frame-infill systems is proposed wherein it is assumed that the primary structural system (the frame) constrains the form of the deformation of secondary structural elements (the infill panels). It is suggested that such a constraint approach may be considered to be generally useful in modeling the behavior of certain classes of secondary structural elements. This constraint approach, as developed here, is an approximate finite element substructuring technique that has the effect of reducing the analytical complexity of frame-infill systems and leads naturally to the development of a group of computationally attractive 12 degree of freedom infill elements that may simply be 'plugged' into conventional frame analysis programs.