[This article belongs to Volume - 54, Issue - 09]
Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-13-11-2022-401

Title : Experimental and Numerical Analysis on Damage Mechanism of Fire-redardant Coating in Small-scale Steel Frame Under Earthquake
QIU Canghu, ZHANG Gengyuan, JIAO Bing, WANG Yong,

Abstract :

To investigate the damage mechanism of the thick coating in the steel frames under earthquake, one small-scale experiment was conducted. The failure modes and positions of the thick coating in the steel beam and columns were observed in detail. The inter-story displacement angle, beam, and column strain of steel frame structure under earthquake were obtained, and the relationship between inter-story displacement angle, strain, and the failure of the coating was analyzed. Based on the software ABAQUS, the elastoplastic damage model was used to predict the damage and fell-off behavior of the coating. In addition, the fell off and the failure mechanism of the thick coating in one steel column reported by the literature and the beam, column, and connection of the present steel frame were analyzed, and a comparison between the theoretical and experimental results was conducted. Results showed that the coating fell off on the web of the beam and the column did not occur, and it easily occurred on the beam-column connection, particularly near the connection region and the top flange of the beam. According to the strains of beam and column under earthquake, it was found that the position beyond the steel yield strain was corresponding to the part where the coating falls off. The Numerical results showed that the steel strain exceeded the yield strain or the inter-story drift ratio exceeded 1/150, and the coating fell off often occurred. Therefore, the elastoplastic damage model can reasonably predict the thick coating falling off. Meanwhile, the coating equivalent plastic strain distribution, the fell off position and the steel equivalent plastic strain conformed to the Mises stress distribution. In other words, larger steel equivalent strain and the Mises stress easily led to the coating fell off. It was found that the coating equivalent strain has an important effect on its fell off, and the thick coating effective plastic failure strain 0.002 could be used in the numerical analysis. In all, the presented results can be used in the coating design of the large-span steel frame, and thus it has a larger engineering application value