Investigation of Rigid Saddle Connection type II with Reduced Beam Sections and Web Stiffeners by Experimental Method

Document Type : Original Article

Authors

1 Ph.D. Candidate. Department of Civil engineering, Kermanshah branch, Islamic Azad University, Kermanshah, Iran

2 Assistant professor. Department of Civil Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran

3 Associate professor. Department of Civil Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran

Abstract

In the past years, the use of steel structures with Saddle (khorjini) beam to column connections was one of the common construction methods in Iran. But the behavior of steel buildings with this type of connection in earthquakes such as Manjil 1369 and Bam 1382 showed the failure of connections before the failure of beams and columns. Considering the advantages of this connection, if new details and proper performance are provided, The Saddle connection can be used as a suitable connection in modern steel structures. For this purpose, in this paper, a new rigid saddle connection with reduced beam sections (RBS) for earthquake-resistant steel structures is presented. In the rigid saddle connection, two beams pass continuously on both sides of the column and are connected to the column by vertical plates. The RBS method has disadvantages such as local buckling of the web and lateral torsional buckling, to avoid these weaknesses and improve the performance of the connection, diagonal stiffeners were used in the beam web. Three laboratory samples were made and tested using IPE 140 profiles. According to the results obtained from these experimental tests, it was found that the sample with a reduced cross-section can withstand a rotation of 0.06 radians and the sample with stiffeners can withstand a rotation of 0.07 radians without any significant drop in the strength, which shows that both connections have an acceptable performance considering the Requirements of the AISC standard, and are placed in the category of rigid connections that can be used in the special moment frame systems. Also, the use of diagonal stiffeners increases energy dissipation and plastic rotation capacity of the connection.

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