Nonlinear Analysis on Prying of Top-and Seat-Angle Connections

Abstract

Nonlinear finite element (FE) analyses are performed to simulate the behavior of top-and seat-angle connections. Contact model with small sliding option is applied between contact pair surfaces of all connecting elements. Bolt pretension force is introduced in the initial steps of analysis. Numerical analysis results together with the prediction by Kishi-Chen power model are compared with experimental ones to examine the applicability of proposed analysis method and power model. The study is farther extended by analyzing the models varying connection parameters, material properties of connection assemblages, and magnitude of bolt pretension. The following results are obtained: 1) bolt sustains additional tensile force due to prying action; 2) prying force develops more quickly due to increment of bolt diameter, gage distance from angle heel to the centerline of bolt hole, and reduction of angle thickness; and 3) bolt pretension increases the initial connection stiffness.

Monotonic and Hysteresis Behavior of Semirigid CFT Column-to-Beam Connections with a Top-Seat Angle

“…상･하부 ㄱ형강 접합부는 부분강접 접 합부의 한 형태로 중･저층 건물에 적합하다. 이러한 상･하 부 ㄱ형강 접합부는 실험적 연구 [2], [3], [4] 를 예측을 위한 해석모델을 제안하였으며 [6], [7], [8], [9], [10], [11], [12], [13], [14] , Chen , [15] , Chen 등 [16], [17] , Faella 등 [18], [19], [20] 과 같이 AISC 내진설계 매뉴얼 [22] 에서 제시한 단조증가 반 복하중이력을 이용하였다.…”

Modified Three-Parameter Power Model to Predict Moment-Rotation Curve of Top- and Seat-Angle Connection

“…The formulation determining the ultimate connection moment M u is proposed assuming two types of simple mechanisms of connection failure using the T-stub concept of "Eurocode 3" [2]. The locations of plastic hinges in the failure mechanism assumed by the power model [1] are revised based on the deformation patterns of the connections reproduced by FE analyses [3,4,6] and experiments [5,7,8]. In this formulation the effects of prying action, bolt stiffness, and bending and shear deformations of the tension angle are considered.…”

“…Bolt stiffness, shear and bending deformation of tension angle and prying force acted on tension angle are considered to determine the ultimate moment of connections implementing two possible failure mechanisms. These failure mechanisms are developed based on the concept of T-stub model [2] and adjusted the position of plastic hinges applying advanced FE analysis method [3][4][5][6]. Then, moment-rotation (M−θ r ) characteristics of top-and seat-angle connections are constructed applying proposed modified three-parameter power model.…”

“…Then, moment-rotation (M−θ r ) characteristics of top-and seat-angle connections are constructed applying proposed modified three-parameter power model. Applicability of the proposed formulation is examined by comparing M−θ r curves and ultimate moment capacities with those of Kishi-Chen power model, FE analyses [3,4] and experiments [7,8]. The comparison implies that proposed formulation and Kishi-Chen's method both achieved closer approximation for maximum of cases and better accuracy for the modified cases to drive M−θ r curves of the connections; but ultimate moments of the connections defined by the proposed method is more realistic than that predicted by Kishi-Chen power model.…”

Computational Benchmarks in Simulation of Cyclic Performance of Steel Connections using Three Dimensional Nonlinear Finite Element Method

“…The inelastic behavior of the materials was modeled by using incremental plasticity theory described by the Von Mises yield criterion and the Mroz kinematic hardening model. Kishi et al [7] studied four finite element models to determine the moment rotation characteristics of the top-and seat-angle with double web angle connections under monotonic loading. Effects of bolt pretension were also considered in the finite element model.…”