ELASTO-PLASTIC FINITE ELEMENT ANALYSIS OF PRYING OF TOP-. AND SEAT-ANGLE CONNECTIONS

M. Komuro1, N. Kishi1 and A. Ahmed2

1 Department of Civil Engineering and Architecture, Muroran Institute of Technology, Muroran 050-8585 Japan, E-mail: komuro@news3.ce. muroran-it. ac. jp 2Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec H3G1M8, Canada

Abstract

In order to precisely investigate an interaction between column flange and top angle’s vertical leg and the effects including prying action of bolts on M — 9r characteristics of top – and seat-angle connections, nonlinear finite element (FE) analyses for top – and seat-angle connections as one of the angle type connections were performed. In those analysis, contact model with small sliding option was applied between contacting pair surfaces of all connecting elements. Bolt pretension force was introduced in the initial step of analysis. Numerical results together with those estimated by using Kishi-Chen power model were compared with the experimental ones to examine those applicabilities. Parametric study was also performed by varying connection parameters, material properties of connection assemblages, and magnitude of bolt pretension. From this study, the following results are obtained: (1) proposed numerical analysis method can be applicable to estimate elasto-plastic nonlinear behavior of angle type connections; (2) pretension force of bolts has no effect on prying action at the initial and ultimate level of loading, but gives some effects a little at the intermediate loading level; (3) a prying action can be increased with decreasing the thickness of flange angle or increasing of gage distance from the angle heel to the centerline of bolt hole; and (4) the initial connection stiffness and ultimate moment capacity of the connections can be increased due to increasing of angle thickness, beam depth and bolt diameter, and decreasing of gage distance.

Keywords: prying force, FE analysis, top – and seat-angle connection, moment-rotation behavior

Introduction

It is widely known that the behavior of bolted connection is significantly influenced due to a prying action. Many researchers have attempted to investigate nature and influence of prying action on connection behavior and the supporting point for prying action of angle, etc. Fleischman (1988) and Chasten et al. (1989) had investigated the effect of prying action by tension bolts experimentally. It is confirmed by them that the interaction between top angle and column flange causes additional tension force in bolts due to prying action, which may depend on the factors such as: bending stiffnesses of bolt and top angle, and location of connecting bolts.

In this paper, in order to precisely investigate an interaction between column flange and top angle’s vertical leg and the effects including bolt action on M — 9r characteristics of top – and seat – angle connections, an elasto-plastic finite element (FE) analysis was performed by using ABAQUS code. The performance of the FE analysis was discussed by comparing with the experimental moment-rotation results conducted by Azizinamini et al. (1985) and Harper (1990). It is confirmed from the comparison that the nonlinear moment-rotation behavior of top – and seat-angle connections

289

M. Pandey et al. (eds), Advances in Engineering Structures, Mechanics & Construction, 289-301.

© 2006 Springer. Printed in the Netherlands.

FE model

Column

section

Beam

section

Top and seat angles

Bolt

diameter

db

(mm)

Angle

section

/

(mm)

g

(mm)

r

(mm)

q

(mm)

Al, FE5, FE6, Alnp

W12*96

W14X38

L6x4x3/8

203

64

140

89

22

A2, FE8, A2np, FE8np

W12x96

W14x38

L6x4xV2

Test 3

W8x24

W8x21

L6x3’/2×3/8

152

51

89

70

FE1, FE7, FElnp, FE7np

W12x96

W14x38

L6x4x3/4

203

64

140

89

FE2, FE2np

W12x96

W14x38

L6x3!/2×3/8

51

FE3, FE3np

W12x96

W14x38

L6x6x3/8

114

FE4, FE4np

W12x96

W14x38

L6x4x‘/2

63.5

19

FE9, FE9np

W12x96

W8x28

L6x4x3/8

22

FE10, FElOnp

W12x96

W8x28

L6x4x‘/2

FE11, FEllnp

W12x96

W8x28

L6x4x3/4

FE12, FE12np

W12x96

W8x28

ЬбхЗ’/^/ц

51

FE13,FE13np

W12x96

W8x28

L6x6x3/8

114

for large deformation region can be analyzed by using proposed FE analysis method taking preten­sion force of bolts, contact effects and sliding frictional effects of connecting elements into account. In addition, an applicability of Kishi-Chen power model was also verified by comparing with the experimental as well as the numerical results from FE analysis.

A parametric study was also conducted to investigate the effect of parameters on prying action and moment-rotation behavior of the connections. In this analysis, the dimensions of connection models, material properties of the connection components, and magnitude of the pretension forces surcharged to the bolts were taken as variables.

FE Analysis Method