Incorporating the Prying Force Effect in the Design of Four-Bolt End Plate Beam-to-Column Moment Connections

Gholipour Feizi, Mahdi; Hosseinzadeh, Yousef; Sheidaii, Mohammad Reza; Alipoursajedi, Soheil

doi:10.22065/jsce.2025.539009.3790

Incorporating the Prying Force Effect in the Design of Four-Bolt End Plate Beam-to-Column Moment Connections

Document Type : Original Article

Authors

Mahdi Gholipour Feizi ¹

Yousef Hosseinzadeh ²

Mohammad Reza Sheidaii ³

Soheil Alipoursajedi ⁴

¹ Assistant Professor، Department of Civil Engineering، Sou.C.، Islamic Azad University، Soufian، Iran

² Professor، Structural Eng. Dept.، Faculty of Civil Engineering، University of Tabriz، Tabriz، Iran

³ Professor، Civil Eng. Dept.، Faculty of Engineering، University of Urmia، Urmia، Iran

⁴ Ph.D. Candidate، Civil Eng. Dept.، Faculty of Engineering، University of Urmia، Urmia، Iran

10.22065/jsce.2025.539009.3790

Abstract

The failure of welded moment connections and the superior seismic performance of bolted moment connections in recent earthquakes have led to the increasing adoption of bolted connections in steel structures. The prying action in beam-to-column bolted moment connections can lead to brittle failure of connections. Conventional design methods mitigate this prying effect by using stiffeners or thicker endplates to reduce its influence. This study presents a method for determining the appropriate plate thickness and bolt diameter in a T-shaped bolted connection component by accounting for the prying effect. Furthermore, the moment connection design method outlined in the AISC code is extended to develop a new approach for designing four-bolt end plate connections that explicitly considers the prying action. A bolted moment beam-to-column connection has been designed using both the AISC prequalified moment connection design methodology and the proposed design approach. The performance of both connections is evaluated and compared using IDeaStatiCa software. The equivalent plastic strain of the designed connections, both with and without the application of prying force, is within the allowable limit. Incorporating the prying effect results in increased bolt diameter and decreased thickness of the beam-to-column endplate. This effect reduces contact pressure at the interface between the endplate and the column by approximately 23.57%. Additionally, in the analyzed connections, bolt tension and shear forces increase by approximately 25% and 45%, respectively.

Keywords

Four-Bolt End Plate Moment Connections

Prying Force

Analytical Model

Plastic Strain

Design of End Plate Moment Connection

Subjects

Structural Analysis and Design (Steel)

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