Fiber Heat Transfer Element for Modeling the Thermal Response of Structures in Fire

This paper introduces a novel type of heat transfer finite element that can be used to model the three-dimensional thermal response of structural beams and columns subjected to elevated temperatures associated with fire. The element is a three-node heat transfer element that uses a fiber discretization to account for both transverse and longitudinal temperature variations in a structural member. This fiber heat transfer element is purposely formulated to be compatible with any fiber beam-column finite element in a sequentially coupled thermal-mechanical analysis of a structural frame subjected to fire. The element is implemented in ABAQUS using a user-defined element subroutine. To demonstrate the capabilities of the fiber heat transfer element, analyses are performed on members with various types of thermal boundary conditions. Results indicate that the fiber heat transfer element offers excellent accuracy with minimal computational expense, making the fiber heat transfer element a valuable tool for modeling the behavior of frame structures in fire.