Research on fire resistance and material model development of CLT components based on OpenSees

Abstract

When analyzing the fire resistance of cross-laminated timber (CLT) components, the finite element software plays an important role. However, the traditional finite element software has disadvantages including high calculation cost, lengthy duration, and unsatisfactory calculation efficiency. Although Open System for Earthquake Engineering Simulation (OpenSees) advanced open-source software has been widely used in fire analysis of steel and concrete structures, it lacks modules and material models related to fire resistance analysis of wood members. To give full play to the open source status as well as the efficiency and exploitability of OpenSees, a new material model known as TimberEC5 is developed and added to the calculation to analyze the heat transfer of wood components. Then, EPTimber, EPTimberThermal, and EPTimberThermalAfter materials are developed in OpenSees to reflect changes in the mechanical properties of wood at ambient temperature and during and after exposure to high temperatures, respectively. The accuracy of the material model developed in this paper is verified by comparing the simulated and experimental values. Finally, the material model is used to analyze the residual carrying capacity of CLT walls after a fire and the fire resistance of a CLT floor. In particular, the effects of the span-to-height ratio (wall), height-to-thickness ratio (floor) laminate composition on the residual carrying capacity of the wall and the fire resistance of the floor are evaluated, and the corresponding change laws are determined