Numerical simulation method for quantitative assessment of fully-grouted sleeve connection damage state and performance under thermal coupling

Abstract

Post-earthquake secondary fire is the major hazard prefabricated concrete (PC) structures face and is currently a hot research topic. Fully-grouted sleeve connection (FGSC) is the main connection method for PC structures, whose failure can result in serious consequences. However, the research on FGSC with tensile damage at elevated temperatures is limited and only at the experimental stage. To enrich the related studies, we proposed a 2D model that considers material damage in good agreement with the corresponding experimental results. 15 finite element models are established with two key parameters, tensile displacement, and temperature, to further investigate the mechanical performance of FGSC under force-thermal coupling. The temperature and damage distribution of FGSC are presented, in addition to the critical temperatures that cause the force state to change. The study results show that the damage pattern of FGSC mainly depends on the tensile phase, and the temperature-induced force can create non-negligible damage to the material. Based on this, the trends of axial and radial forces of FGSC have been summarized as well as their new prediction equations whose coefficients of determination are 99.36 % and 99.83 % in the elevated temperature stage. The numerical simulation method and conclusions obtained are the essential basis for the subsequent study of the response of PC structures under post-earthquake secondary fires.