A study of the seismic effects on a portal frame having a hole at the beam-column connection

Abstract This paper presents the results of the study on thin walled steel portal frames, which are used in Japan as basic structural frames for motorway viaducts. A serious problem found in many such frames is the development of fatigue cracks at the beam to column connection. To act as a measure against the fatigue failure, in some cases a hole is provided at the beam-column connection of the frames. In this study, dynamic analysis using real earthquake data from 3 different earthquakes were carried out to examine the influence of such a hole on the global behavior of the frame and also on the local out of plane displacement around the location of the hole. Non-linear, large displacement analysis was performed using the FEM program MSC. Marc. The hole radius was varied and used as a parameter of study. The hole had significant effect on local out of plane displacement and global behavior, specifically when the radius of the hole was larger than 100 mm.

[1]  Shigeki Unjoh,et al.  SEISMIC DESIGN OF HIGHWAY BRIDGES , 2004 .

[2]  Tetsuhiro Shimozato,et al.  FATIGUE PERFORMANCE OF BEAM-TO-COLUMN CONNECTIONS WITH BOX SECTIONS IN STEEL BRIDGE FRAME PIERS , 2002 .

[3]  Kunihiro Morishita,et al.  APPLICABILITY ON DYNAMIC VERIFICATION METHOD FOR SEISMIC DESIGN OF STEEL BRIDGE PIERS , 2002 .

[4]  Zhi-Gang Xiao,et al.  A method of determining geometric stress for fatigue strength evaluation of steel welded joints , 2004 .

[5]  Gary Marquis,et al.  A fatigue assessment method based on weld stress , 2006 .

[6]  Chitoshi Miki,et al.  STUDY ON FATIGUE CRACKING IN STEEL BRIDGE PIERS WITH BOX SECTION AND TEMPORALLY REPAIRING , 2002 .

[7]  W. Geary.  A review of some aspects of fatigue crack growth under variable amplitute loading , 1992 .

[8]  Pingsha Dong,et al.  A structural stress definition and numerical implementation for fatigue analysis of welded joints , 2001 .

[9]  John W. Fisher.  Fatigue and Fracture in Steel Bridges: Case Studies , 1984 .

[10]  日本鋼構造協会,et al.  Fatigue design recommendations for steel structures , 1995 .

[11]  Tsutomu Usami,et al.  Inelastic seismic design verification method for steel bridge piers using a damage index based hysteretic model , 1998 .

[12]  R. Ritchie,et al.  Fatigue Crack Propagation in 2090 Aluminum-Lithium Alloy: Effect of Compression Overload Cycles , 1987 .

[13]  J. G. S. da Silva,et al.  Nonlinear dynamic analysis of steel portal frames with semi-rigid connections , 2008 .

[14]  M. A. Wahab,et al.  Extremely Low Cycle(ELC) Fatigue Cracking Behaviour in Steel Bridge Rigid Frame Piers (耐震・免震・制震構造と地震防災システムの構築プロジェクト) , 2001 .

[15]  Tim Topper,et al.  Effects of Compression and Compressive Overloads on the Fatigue Behavior of a 2024-T351 Aluminum Alloy and a SAE 1045 Steel , 1988 .

[16]  Kazuhiro Nishikawa,et al.  Retrofitting for seismic upgrading of steel bridge columns , 1998 .

[17]  Toshiyuki Kitada,et al.  New technologies of steel bridges in Japan , 2002 .

[18]  Shigeru Shimizu.  Strength of a corner zone of a frame structure with a hole to prevent from the fatigue crack , 2008 .