Characterization of in-plane and out of -plane behavior of infill panels subjected to thermal exposure

Several experimental studies have shown that infill panels in a structural frame have a significant effect on their in-plane as well as out-of-plane behavior. While masonry infill offers good resistance to in-plane loads, it is relatively weak under out of plane loading. Exposure to thermal gradients (e.g. in case of a fire) induces out of plane loads in masonry infill which can play a key role in its failure. With the advancements in the simulation techniques, numerical modeling of these structural systems has emerged as a promising alternative. This study details the development and calibration of a generic 3D finite-element model to determine the impact of thermal exposure on structural frames with and without masonry infill panels. The parametric studies under various thermal exposures on in-plane and out-of-plane behavior of these structural systems manifest the potential of fire for inducing instability, and degrading stiffness of the same. The parametric studies show that even for the least fire severity levels thermal exposure induced significant instability and stiffness degradation for both structural systems. Also, these studies reveal that infill-panel not only enhances the out-of-plane displacements for structural frame but also increases safety risks due to bulging of infill panel. These parametric studies can be further extended and the valuable insights from these can be incorporated into the design process to improve fire safety.