Does the Web of Seismic Walls Play a Role to Their Out-of-Plane Stability?

2021 ◽  
pp. 15-22
Author(s):  
Theodoros Chrysanidis ◽  
Ioannis Tegos
Keyword(s):  
Out Of Plane ◽  
The Web

scholarly journals Locally Corroded Stiffener Effect on Shear Buckling Behaviors of Web Panel in the Plate Girder

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Jungwon Huh ◽  
In-Tae Kim ◽  
Jin-Hee Ahn
Keyword(s):  
Corrosion Damage ◽  
Element Analysis ◽  
Buckling Strength ◽  
Lower Shear ◽  
Out Of Plane ◽  
Shear Buckling ◽  
Buckling Failure ◽  
Plane Displacement ◽  
The Web ◽  
Plate Girder

The shear buckling failure and strength of a web panel stiffened by stiffeners with corrosion damage were examined according to the degree of corrosion of the stiffeners, using the finite element analysis method. For this purpose, a plate girder with a four-panel web girder stiffened by vertical and longitudinal stiffeners was selected, and its deformable behaviors and the principal stress distribution of the web panel at the shear buckling strength of the web were compared after their post-shear buckling behaviors, as well as their out-of-plane displacement, to evaluate the effect of the stiffener in the web panel on the shear buckling failure. Their critical shear buckling load and shear buckling strength were also examined. The FE analyses showed that their typical shear buckling failures were affected by the structural relationship between the web panel and each stiffener in the plate girder, to resist shear buckling of the web panel. Their critical shear buckling loads decreased from 82% to 59%, and their shear buckling strength decreased from 88% to 76%, due to the effect of corrosion of the stiffeners on their shear buckling behavior. Thus, especially in cases with over 40% corrosion damage of the vertical stiffener, they can have lower shear buckling strength than their design level.

Longitudinal and Out-of-Plane Stiffness of a Web in an Air-Flotation Oven

1999 ◽  
Author(s):  
Young B. Chang ◽  
Ronald P. Swanson ◽  
Peter M. Moretti
Keyword(s):  
Analytical Model ◽  
Experimental Results ◽  
Photographic Film ◽  
Longitudinal Stiffness ◽  
Out Of Plane ◽  
Air Cushion ◽  
Air Flotation ◽  
Low Tension ◽  
The Web ◽  
Web Tension

Abstract Air-flotation ovens are used for non-contact drying of coated web materials such as photographic film, magnetic media, and paper. In a typical air-flotation oven, the air bars are arranged in such a way that the path of web is nearly sinusoidal. When web tension fluctuates, the distance between the web and the air bars also changes. This phenomenon affects the longitudinal dynamics and tension control of an air-floated web. In some cases, tension fluctuations can cause the web to touch the air bars, resulting in damage to the coating and the web. This paper discusses an analytical model of the extensional resiliency of an air-floated web. The analysis shows that at low tension the longitudinal stiffness of an air-floated web is small, being dominated by the air cushion effects. At higher web tension, however, the effects of material deformation become more important than the air cushion effects. The analysis is compared with the experimental results obtained in a pilot air-flotation oven. The analytical and experimental results show the same trends, though the analytical model tends to underpredict the longitudinal stiffness of air-supported webs.

Distortion Induced Fatigue Analysis of Steel Bridges

2012 ◽  
Vol 525-526 ◽  
pp. 133-136
Author(s):  
Chun Sheng Wang ◽  
Sheng Long Yan ◽  
Jun Cheng
Keyword(s):  
Numerical Analysis ◽  
Fatigue Cracking ◽  
Steel Bridges ◽  
Steel Bridge ◽  
Ansys Software ◽  
Fatigue Stress ◽  
Double Curvature ◽  
Out Of Plane ◽  
Analysis Models ◽  
The Web

Induced forces in secondary steel bridge members such as diaphragms and cross-bracing can cause out-of-plane distortion in webs that may lead to fatigue cracking. Such cracking is most likely to occur if the distortion must be accommodated in a short length of the web, such as in the gap between the end of transverse stiffeners and girder flanges, thats because the web gap is subject to double curvature. In this paper, the numerical analysis models of the curved continue steel bridges were established using ANSYS software to calculate the fatigue stress at the web gaps. The numerical analysis results show that both the bottom web gap at middle span area and the top web gap at supported were poor fatigue details, and web thickness and web gap depth give the great affection on the out-of-plane distortion fatigue stress at web gaps of curved steel bridges.

Fatigue cracking in bridges from out-of-plane displacements

1978 ◽  
Vol 5 (4) ◽  
pp. 542-556 ◽  
Author(s):  
John W. Fisher
Keyword(s):  
Fatigue Cracking ◽  
Bridge Structure ◽  
Laboratory Studies ◽  
Relative Movement ◽  
Cyclic Stresses ◽  
The Future ◽  
Out Of Plane ◽  
Web Stiffeners ◽  
Plane Bending ◽  
The Web

The interaction of the various components of a bridge structure under normal vehicular loading has sometimes resulted in cracking in unexpected locations in relatively short periods of time. In girder type bridges this cracking has often occurred in the web at short gaps between attachments and the flanges. Although the problem has been more prevalent with welded members, cracking has also occurred in riveted members.This paper examines three cases of fatigue cracking from out-of-plane displacements: one case in which transportation and handling resulted in high cyclic stresses at the ends of transverse web stiffeners; a second case in which the end rotation of transverse floor beams framing into longitudinal girder webs resulted in cracking at the end of the connection plates welded to the girder web; and a third case in which riveted connection plates connecting cantilever brackets to floor beams were found to be susceptible to in-plane bending as a result of relative movement between the girder and the floor system.Field and laboratory studies were beneficial in assessing the mode of behavior and causes of fatigue cracking. The results of these studies were useful in developing ways to avoid such cracking in the future.

scholarly journals Lateral Deflections of Webs in Air-Flotation Ovens

2004 ◽  
Vol 71 (3) ◽  
pp. 314-320 ◽  
Author(s):  
Peter M. Moretti
Keyword(s):  
Control Mechanism ◽  
Continuous Representation ◽  
Stability And Control ◽  
Lateral Forces ◽  
Out Of Plane ◽  
Lateral Curvature ◽  
And Control ◽  
Stretching Effect ◽  
The Web ◽  
Lateral Deflections

A long web span supported by many, regularly spaced, alternating air-bars is studied. The focus is on the lateral forces on the web due to the interaction of lateral curvature with out-of-plane deflections. The effect of stretching of the elastic web material is included, and the effect of high web speed is handled by distinguishing between the tension in the material Tmat and the apparent tension Tapp=Tmat−μv2. The governing partial differential equations for a continuous representation of the web’s lateral deflection, stability, and control is developed for both straight and cambered webs. The dimensionless parameters for web-tension effect, web-camber effect, and stretching effect are identified. The influence of tilted air-bars is studied, towards developing a control mechanism to compensate for camber.

Out-Plane Distortion Induced Fatigue Analysis of Steel Bridges

2010 ◽  
Vol 452-453 ◽  
pp. 165-168
Author(s):  
Zhi Ping Wu ◽  
Chun Sheng Wang ◽  
Feng Cheng
Keyword(s):  
Numerical Models ◽  
Structural Parameters ◽  
Fatigue Cracking ◽  
Steel Bridge ◽  
Analysis Model ◽  
Ansys Software ◽  
Fatigue Stress ◽  
Double Curvature ◽  
Out Of Plane ◽  
The Web

Induced forces in secondary steel bridge members such as diaphragms and cross-bracing can cause out-of-plane distortion in webs that may lead to fatigue cracking. Such cracking is most likely to occur if the distortion must be accommodated in a short length of the web, such as in the gap between the end of transverse stiffeners and girder flanges, because the web gap is subject to double curvature. In this paper, the numerical analysis model of a real 3-span continue steel bridge was established using ANSYS software to calculate the real fatigue stress at the web gaps. Some key structural parameters, for example, web gap depth and web thickness, have been considered in the numerical models. The results show that web thickness and web gap depth give the great affection on the out-of-plane distortion fatigue stress at web gaps.

Traction Between a Web and a Smooth Roller

2004 ◽  
Vol 126 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Sinan Mu¨ftu¨ ◽  
John J. Jagodnik
Keyword(s):  
Air Entrainment ◽  
Air Bearing ◽  
Simultaneous Solution ◽  
Lubrication Equation ◽  
Out Of Plane ◽  
Plane Equilibrium ◽  
Range Of Values ◽  
Roller Radius ◽  
The Web ◽  
Smooth Roller

Web traction over rollers is known to deteriorate due to air entrainment at high web speeds. In this paper, a general model is presented to predict the traction capability of an impermeable web over a smooth roller. The model considers the effects of the web and roller speeds, roller radius, combined roughness of the two surfaces, web tension and thickness, friction coefficient, and compressible air bearing. The change of tension ΔN due to mechanical slip between the roller and the web is calculated by a simultaneous solution of the in-plane and out-of-plane equilibrium of the web and the compressible Reynolds lubrication equation. The problem is nondimensionalized and the effects of nine of the eleven nondimensional parameters on traction are investigated for a range of values. Formulas involving the nondimensional parameters for the traction capability are presented in two-variable polynomial forms.

scholarly journals Relationships between Imperfections and Shear Buckling Resistance in Web Plate with Sectional Damage Caused by Corrosion

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Jin-Hee Ahn ◽  
Shigenobu Kainuma ◽  
Won-Hong Lee ◽  
Youn-Ju Jeong ◽  
In-Tae Kim
Keyword(s):  
Aspect Ratio ◽  
Plane Deformation ◽  
Corrosion Damage ◽  
Fe Analysis ◽  
Analysis Model ◽  
Buckling Resistance ◽  
Out Of Plane ◽  
Shear Buckling ◽  
Simple Evaluation ◽  
The Web

This study deals with the relationship between imperfections and shear buckling resistance of web plates with sectional damage caused by corrosion. To examine the imperfection effect on the shear buckling resistance of a web plate with sectional damage, a series of nonlinear finite element (FE) analyses were carried out for a web plate with sectional damage, which was assumed as local corrosion damage. For considering imperfections of the web plate in the girder, initial out-of-plane deformation was introduced in the FE analysis model. Using the FE analysis results, the changes in the shear buckling resistance of the web plate with sectional damage were quantitatively examined and summarized according to the aspect ratio, boundary conditions, and height of the damaged section of the web plate. The effects of web imperfections on the shear buckling resistance were evaluated to be little compared to that of the web plate without sectional damage. The shear buckling resistance was shown to significantly change in the high-aspect-ratio web plate. A simple evaluation equation for the shear buckling resistance of a web plate with sectional damage was modified for use in the practical maintenance of a web plate in corrosive environments.

Out-of-plane buckling of arches with rectangular cross-sections and curved webs

2021 ◽  
Author(s):  
Gilles Van Staen ◽  
Philippe Van Bogaert ◽  
Hans De Backer
Keyword(s):  
Sectional Curvature ◽  
Cross Section ◽  
Cross Sections ◽  
Plate Thickness ◽  
Cross Sectional ◽  
Fem Model ◽  
Out Of Plane ◽  
Arch Bridges ◽  
The Relationship ◽  
The Web

<p>Contemporary arch bridges are mostly designed as slender structures. Due to the presence of mainly compressive forces in the arches, the bridge may become prone to out-of-plane buckling. The main purpose of this research is to examine the influence of the geometric properties of a cross-section of the arch on this behaviour. To this end, a detailed FEM model of an arch bridge is built and validated by the results of a measurement programme. Thereafter, the critical buckling load is examined by numerical and analytical analyses. Furthermore, the influence of the plate thickness and the introduction of a cross-sectional curvature in the web on the buckling behaviour is evaluated. From that, it can be concluded that the relationship between the critical load and moment of inertia around the weak axis of the arch is linear, and in addition independent of the shape of the cross-section. Nevertheless, a cross-sectional curvature in the web shows the most potential in terms of structural efficiency.</p>

The Instability of Webs in Transport

2010 ◽  
Vol 78 (1) ◽  
Author(s):  
J. A. Beisel ◽  
J. K. Good
Keyword(s):  
Finite Element Method ◽  
Cylindrical Shell ◽  
Plate Theory ◽  
Constitutive Relations ◽  
Nonlinear Finite Element ◽  
Nonlinear Finite Element Method ◽  
Process Machinery ◽  
Out Of Plane ◽  
Strain Dependent ◽  
The Web

A method is presented for determining the two levels of instability that are associated with thin web materials traveling through process machinery. The first level of instability involves the out-of-plane buckling of expanses of web supported only by rollers at opposing ends. A method is developed using linear plate theory, which is verified by tests that show that this first level of instability can be predicted. The second level of instability involves the buckling of the web when it has taken the form of a cylindrical shell as it transits a roller. A nonlinear finite element method with strain dependent constitutive relations is developed and verified by tests to predict this second level of instability.

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