Thermal creep mechanical-based modeling for flush endplate connections in fire

•Steady-state temperature FE analyses are evaluated against experimental data at elevated temperatures.•Steady state creep FE analyses predicted the thermal creep response of flush endplates at fire temperature.•A mechanical-based model is developed to predict the creep behavior of flush endplates connection in fire.•A set of data is provide to account for the creep thermal stresses and deformations in designing flush endlplates in fire.

A mechanical-based model is developed to predict the time-dependent effect (thermal creep) and the fast loading-rate behavior of flush endplate connections at elevated temperatures during a fire. The fast loading-rate behavior model consists of multi-linear springs that predict each component stiffness, strength, and rotation. The multi-linear springs temperature expressions are based on the ambient temperature formulations proposed in Eurocode3 Part 1.8 where material properties are considered temperature-dependent. To include the effect of thermal creep in the proposed model, a modified Burgers creep model is developed to predict the time-dependent connection rotation and temperature of flush endplate connections. The modified Burgers creep model consists of linear springs and viscous dashpots that predict the time-dependent connection rotation. The proposed model is validated against experimental results available in the literature and finite element (FE) simulations developed as a part of this study. Through explicit consideration of thermal creep effect, the proposed model helps providing important insights into fire-induced thermal stresses and deformations and their implications on designing of flush endplate connections in fire.