Neural Approximation of the Buckling Coefficient of Compression Flange of Box Girder Evenly Loaded Transversely

2015 ◽  
Vol 797 ◽  
pp. 137-144
Author(s):  
Beata Potrzeszcz-Sut ◽  
Andrzej Szychowski
Keyword(s):  
Normal Stresses ◽  
Longitudinal Stress ◽  
Internal Wall ◽  
Linear Distribution ◽  
Box Girder ◽  
Final Formula ◽  
Coefficient Of Compression ◽  
Buckling Coefficient ◽  
Thin Walled ◽  
Elastically Restrained

There are situations in the thin-walled steel girders with box intersection, in which the internal wall of compression flange is elastically restrained in the webs of section and along its length occurs the change of normal stresses. Such a wall was modelled, as a bilateral elastically restrained internal plate variably loaded at the length. Explicit formulation of neural formula on buckling coefficient of internal plate at non-linear distribution of longitudinal stress was discussed in this paper. A few structures of neural networks (NN) were envisaged in order to obtain the best of the numerical effectiveness of the final formula. The results noted from the literature were used for the evaluation of neural prediction of coefficient.

scholarly journals Buckling Of The Stiffened Flange Of The Thin-Walled Member At Longitudinal Stress Variation

2015 ◽  
Vol 61 (3) ◽  
pp. 149-168
Author(s):  
A. Szychowski
Keyword(s):  
Boundary Conditions ◽  
Free Edge ◽  
Cantilever Plate ◽  
Longitudinal Stress ◽  
Stress Variation ◽  
Buckling Modes ◽  
Load Distributions ◽  
Edge Stiffener ◽  
Thin Walled ◽  
Elastically Restrained

AbstractBuckling of the stiffened flange of a thin-walled member is reduced to the buckling analysis of the cantilever plate, elastically restrained against rotation, with the free edge stiffener, which is susceptible to deflection. Longitudinal stress variation is taken into account using a linear function and a 2nd degree parabola. Deflection functions for the plate and the stiffener, adopted in the study, made it possible to model boundary conditions and different buckling modes at the occurrence of longitudinal stress variation. Graphs of buckling coefficients are determined for different load distributions as a function of the elastic restraint coefficient and geometric details of the stiffener. Exemplary buckling modes are presented.

scholarly journals Computation of Thin-Walled Cross-Section Resistance to Local Buckling with the Use of the Critical Plate Method

2016 ◽  
Vol 62 (2) ◽  
pp. 229-264 ◽  
Author(s):  
A. Szychowski
Keyword(s):  
Cross Section ◽  
Critical Stress ◽  
Analytical Calculation ◽  
Local Buckling ◽  
Stability Loss ◽  
Longitudinal Stress ◽  
Plate Method ◽  
Thin Walled ◽  
The Cross ◽  
Elastically Restrained

Abstract Thin-walled bars currently applied in metal construction engineering belong to a group of members, the cross-section res i stance of which is affected by the phenomena of local or distortional stability loss. This results from the fact that the cross-section of such a bar consists of slender-plate elements. The study presents the method of calculating the resistance of the cross-section susceptible to local buckling which is based on the loss of stability of the weakest plate (wall). The “Critical Plate” (CP) was identified by comparing critical stress in cross-section component plates under a given stress condition. Then, the CP showing the lowest critical stress was modelled, depending on boundary conditions, as an internal or cantilever element elastically restrained in the restraining plate (RP). Longitudinal stress distribution was accounted for by means of a constant, linear or non-linear (acc. the second degree parabola) function. For the critical buckling stress, as calculated above, the local critical resistance of the cross-section was determined, which sets a limit on the validity of the Vlasov theory. In order to determine the design ultimate resistance of the cross-section, the effective width theory was applied, while taking into consideration the assumptions specified in the study. The application of the Critical Plate Method (CPM) was presented in the examples. Analytical calculation results were compared with selected experimental findings. It was demonstrated that taking into consideration the CP elastic restraint and longitudinal stress variation results in a more accurate representation of thin-walled element behaviour in the engineering computational model.

scholarly journals Local buckling of cantilever wall of thin-walled member with longitudinal and transverse stress variation

2015 ◽  
Vol 14 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Andrzej Szychowski
Keyword(s):  
Local Buckling ◽  
Transverse Stress ◽  
Linear Distribution ◽  
Stress Variation ◽  
Plate Buckling ◽  
Thin Walled ◽  
The Stability ◽  
Elastically Restrained ◽  
Distribution Of Stresses ◽  
Plate Width

The paper presents results of the investigation into the stability of elastically restrained cantilever walls (plates) with longitudinal and transverse stress variation. A linear distribution of stresses in the direction of the wall (plate) width and the linear or nonlinear (in accordance with parabola 20) distribution of stresses along the wall length were assumed. Plots of plate buckling coefficients (k) for variously supported and variously loaded cantilever plates, which are not found in the literature, were determined.

scholarly journals Stability and Resistance of Steel Continuous Beams with Thin-Walled Box Sections

2018 ◽  
Vol 64 (4) ◽  
pp. 123-143 ◽  
Author(s):  
K. Brzezińska ◽  
A. Szychowski
Keyword(s):  
Local Buckling ◽  
Effective Characteristics ◽  
Continuous Beam ◽  
Longitudinal Stress ◽  
Stress Variation ◽  
Continuous Beams ◽  
Thin Walled ◽  
Elastically Restrained ◽  
Ultimate Resistance ◽  
The Impact

AbstractThe issues of local stability and ultimate resistance of a continuous beam with thin-walled box section (Class 4) were reduced to the analysis of the local buckling of bilaterally elastically restrained internal plate of the compression flange at longitudinal stress variation. Critical stress of the local buckling was determined using the so-called Critical Plate Method (CPM). In the method, the effect of the elastic restraint of the component walls of the bar section and the effect of longitudinal stress variation that results from varying distribution of bending moments were taken into account. On that basis, appropriate effective characteristics of reliable sections were determined. Additionally, ultimate resistances of those sections were estimated. The impact of longitudinal stress variation and of the degree of elastic restraint of longitudinal edges on, respectively, the local buckling of compression flanges in the span section (p) and support section (s) was analysed. The influence of the span length of the continuous beam and of the relative plate slenderness of the compression flange on the critical ultimate resistance of box sections was examined.

Static response of curved steel thin-walled box-girder bridge subjected to Indian railway loading

2021 ◽  
Vol 108 (2) ◽  
pp. 63-74
Author(s):  
V. Verma ◽  
K. Nallasivam
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Box Girders ◽  
Box Girder ◽  
One Dimensional ◽  
Thin Walled ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Indian Railway ◽  
Different Response

Purpose: The primary objective of the current study is to numerically model the steel thin-walled curved box-girder bridge and to examine its various response parameters subjected to Indian Railway loading. Design/methodology/approach: The analysis is conducted by adopting a one dimensional curved thin-walled box-beam finite beam element based on finite element methodology. The scope of the work includes a computationally efficient, three-noded, one-dimensional representation of a thin-walled box-girder bridge, which is especially desirable for its preliminary analysis and design phase, as well as a study of the static characteristics of a steel curved bridge, which is critical for interpreting its dynamic response. Findings: The analytical results computed using finite element based MATLAB coding are presented in the form of various stress resultants under the effect of various combinations of Indian Railway loads. Additionally, the variation in different response parameters due to changes in radius and span length has also been investigated. Research limitations/implications: The research is restricted to the initial design and analysis phase of box-girder bridge, where the wall thickness is small as compared to the cross-section dimensions. The current approach can be extended to future research using a different method, such as Extended finite element technique on curved bridges by varying boundary conditions and number of elements. Originality/value: The validation of the adopted finite element approach is done by solving a numerical problem, which is in excellent agreement with the previous research findings. Also, previous studies had aimed at thin-walled box girders that had been exposed to point loading, uniformly distributed loading, or highway truck loading, but no research had been done on railway loading. Moreover, no previous research had performed the static analysis on thin-walled box-girders with six different response parameters, as the current study has. Engineers will benefit greatly from the research as it will help them predict the static behaviour of the curved thin-walled girder bridge, as well as assess their free vibration and dynamic response analysis.

Thin‐Walled Multicell Box‐Girder Finite Element

1991 ◽  
Vol 117 (10) ◽  
pp. 2953-2971 ◽  
Author(s):  
A. Ghani Razaqpur ◽  
Hangang Li
Keyword(s):  
Finite Element ◽  
Box Girder ◽  
Thin Walled

Tube-Bulging Under Internal Pressure and Axial Force

1973 ◽  
Vol 95 (4) ◽  
pp. 219-223 ◽  
Author(s):  
D. M. Woo
Keyword(s):  
Internal Pressure ◽  
Numerical Solution ◽  
Axial Force ◽  
Compressive Load ◽  
Experimental Results ◽  
Longitudinal Stress ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Tube Bulging

A numerical solution for analysis of the bulging process of a thin-walled tube under internal pressure and axial force is proposed. The solution is applied to a case in which the longitudinal stress resulted from internal pressure and external compressive load is tensile along the whole length of the bulged tube. To verify whether the solution is applicable, theoretical and experimental results on the bulging of copper tubes have been obtained and are compared in this paper.

GBT FORMULATION TO ANALYZE THE BUCKLING BEHAVIOR OF THIN-WALLED MEMBERS SUBJECTED TO NON-UNIFORM BENDING

2007 ◽  
Vol 07 (01) ◽  
pp. 23-54 ◽  
Author(s):  
RUI BEBIANO ◽  
NUNO SILVESTRE ◽  
DINAR CAMOTIM
Keyword(s):  
Finite Element ◽  
Major Axis ◽  
Shear Stresses ◽  
Longitudinal Stress ◽  
Stress Gradients ◽  
Stiffness Reduction ◽  
Buckling Behavior ◽  
Global Buckling ◽  
Thin Walled ◽  
Uniformly Distributed Loads

In this paper, one investigates the local-plate, distortional and global buckling behavior of thin-walled steel beams subjected to non-uniform bending moment diagrams, i.e. under the presence of longitudinal stress gradients. One begins by deriving a novel formulation based on Generalized Beam Theory (GBT), which (i) can handle beams with arbitrary open cross-sections and (ii) incorporates all the effects stemming from the presence of longitudinally varying stress distributions. This formulation is numerically implemented by means of the finite element method: one (i) develops a GBT-based beam finite element, which accounts for the stiffness reduction associated to applied longitudinal stresses with linear, quadratic and cubic variation, as well as to the ensuing shear stresses, and (ii) addresses the derivation of the equilibrium equation system that needs to be solved in the context of a GBT buckling analysis. Then, in order to illustrate the application and capabilities of the proposed GBT-based formulation and finite element implementation, one presents and discusses numerical results concerning (i) rectangular plates under longitudinally varying stresses and pure shear, (ii) I-section cantilevers subjected to uniform major axis bending, tip point loads and uniformly distributed loads, and (iii) simply supported lipped channel beams subjected to uniform major axis bending, mid-span point loads and uniformly distributed loads — by taking full advantage of the GBT modal nature, one is able to acquire an in-depth understanding on the influence of the longitudinal stress gradients and shear stresses on the beam local and global buckling behavior. For validation purposes, the GBT results are compared with values either (i) yielded by shell finite element analyses, performed in the code ANSYS, or (ii) reported in the literature. Finally, the computational efficiency of the proposed GBT-based beam finite element is briefly assessed.

Transverse Ribs Affect the Stability of Steel-Concrete Composite Box Beams

2014 ◽  
Vol 587-589 ◽  
pp. 1663-1667
Author(s):  
Chong Yang Zhou ◽  
Jian Rong Yang ◽  
Wan Wan Jiang
Keyword(s):  
Finite Element Method ◽  
The Finite Element Method ◽  
Box Girder ◽  
Linear Buckling ◽  
Box Beams ◽  
Buckling Coefficient ◽  
Stiffening Ribs ◽  
The Stability ◽  
Lateral Bracing ◽  
Linear Buckling Analysis

The paper uses the finite element method to the specific structure of the linear buckling analysis to study the steel - concrete buckling coefficient changes when the changes and adjustments in the case of composite box girder structure different density transverse stiffening ribs buckling coefficient bracing spacing, Thus obtained that the almost linear relationship between the change in distance between the transverse stiffening ribs and buckling coefficient. Meanwhile get when bracing spacing when a valid range, coefficient of variation of buckling structure is not particularly obvious. Which is to adjust the spacing and lateral bracing number of stiffening ribs provide a space.

Vibration of Thin-Walled Box-Girder Bridges Excited by Vehicles

1995 ◽  
Vol 121 (9) ◽  
pp. 1330-1337 ◽  
Author(s):  
Dongzhou Huang ◽  
Ton-Lo Wang ◽  
Mohsen Shahawy
Keyword(s):  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Thin Walled
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