Material model development and fire resistance research on CLT wall-floor angle bracket connections in OpenSees

Abstract

When analyzing the fire resistance of cross-laminated timber (CLT) joints, traditional finite element (FE) analysis software encounters problems such as long computing times and low calculation efficiency. This situation is more common when performing multi-physics coupling analysis. OpenSees is open-source software that has high computational efficiency and the advantage that it can be developed by users. It is widely used in analyses of the effects of fire on steel and concrete structures, but it contains no analogous material model for timber connections. To make full use of the calculation efficiency of OpenSees, this study adds a spring element constitutive model that enables the simulation of CLT wall-floor angle bracket connections during and after a fire, and the calculation of CLT node thermo-mechanical coupling. The proposed model numerically simulates and analyzes the fire resistance of CLT wall-floor angle bracket connections, the effects of different load ratios (5–80%) and of two different length self-tapping screws (60 and 80 mm), and different tree species. This provides a source for designers when using open-source software to analyze the fire resistance of CLT joints.