Computer analysis of thin-walled concrete box beams

1989 ◽  
Vol 16 (6) ◽  
pp. 902-909 ◽  
Author(s):  
Shahbaz Mavaddat ◽  
M. Saeed Mirza
Keyword(s):  
Key Words ◽  
Computer Analysis ◽  
Shear Stresses ◽  
Shear Lag ◽  
Applied Loading ◽  
Box Beam ◽  
Box Beams ◽  
Three Stages ◽  
Thin Walled ◽  
Normal And Shear Stresses

Three computer programs, written in FORTRAN WATFIV, are developed to analyze straight, monolithically cast, symmetric concrete box beams with one, two, or three cells and side cantilevers over a simple span or over two spans with symmetric mid-span loadings. The analysis, based on Maisel's formulation, is performed in three stages. First, the structure is idealized as a beam and the normal and shear stresses are calculated using the simple bending theory and St-Venant's theory of torsion. The secondary stresses arising from torsional and distortional warping and shear lag are calculated in the second and third stages, respectively. The execution times on an AMDAHL 580 system are 0.02, 0.93, and 0.25 s for the three programs, respectively. The stresses arising in each stage of analysis are then superposed to determine the overall response of the box section to the applied loading. The results are compared with Maisel's hand calculations. Key words: bending, bimoment, box beam, computer analysis, FORTRAN, shear, shear lag, thin-walled section, torsion, torsional and distortional warping.

Ultimate load analysis of thin-walled box beams considering shear lag effect

2004 ◽  
Vol 42 (8) ◽  
pp. 1199-1210 ◽  
Author(s):  
Yaping Wu ◽  
Shaoshui Yu ◽  
Chonghui Shi ◽  
Jianjun Li ◽  
Yuanming Lai ◽  
...  
Keyword(s):  
Ultimate Load ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Lag Effect ◽  
Box Beams ◽  
Thin Walled ◽  
Load Analysis

Vertical Deflection of Simply Supported Box Beam with Corrugated Steel Webs Including Effects of Shear Lag and Shear Deformation

2012 ◽  
Vol 204-208 ◽  
pp. 1012-1016 ◽  
Author(s):  
Wei Ji ◽  
Shi Zhong Liu
Keyword(s):  
Finite Element Method ◽  
Shear Deformation ◽  
Comprehensive Analysis ◽  
Shear Lag ◽  
The Finite Element Method ◽  
Vertical Deflection ◽  
Simply Supported ◽  
Box Beam ◽  
Box Beams ◽  
Good Agreement

This paper presents an method to solve the vertical deflection of the box beams with corrugated steel webs, considering both the shear lag and shear deformation of corrugated steel webs. The method is deduced by means of the variational principle. The formulas given by this method is simple and practical. Then, a comprehensive analysis on the effects of shear lag and shear deformation of corrugated steel webs is given for a simply supported box beam with corrugated steel webs under uniformly distributed. The results of vertical deflection obtained by this paper are in good agreement with those obtained by the finite element method (FEM) and the model test, respectively.

Matrix Analysis of Shear Lag and Shear Deformation in Thin-Walled Box Beams

2003 ◽  
Vol 129 (8) ◽  
pp. 944-950 ◽  
Author(s):  
Yaping Wu ◽  
Shizhong Liu ◽  
Yuanlin Zhu ◽  
Yuanming Lai
Keyword(s):  
Shear Deformation ◽  
Matrix Analysis ◽  
Shear Lag ◽  
Box Beams ◽  
Thin Walled

Exact Matching Condition at a Joint of Thin-Walled Box Beams Under Out-of-Plane Bending and Torsion

2012 ◽  
Vol 79 (5) ◽  
Author(s):  
Soomin Choi ◽  
Gang-Won Jang ◽  
Yoon Young Kim
Keyword(s):  
Beam Theory ◽  
Matching Condition ◽  
Higher Order ◽  
Transformation Matrix ◽  
Exact Matching ◽  
Box Beam ◽  
Out Of Plane ◽  
Box Beams ◽  
Thin Walled ◽  
Plane Bending

To take into account the flexibility resulting from sectional deformations of a thin-walled box beam, higher-order beam theories considering warping and distortional degrees of freedom (DOF) in addition to the Timoshenko kinematic degrees have been developed. The objective of this study is to derive the exact matching condition consistent with a 5-DOF higher-order beam theory at a joint of thin-walled box beams under out-of-plane bending and torsion. Here we use bending deflection, bending/shear rotation, torsional rotation, warping, and distortion as the kinematic variables. Because the theory involves warping and distortion that do not produce any force/moment resultant, the joint matching condition cannot be obtained just by using the typical three equilibrium conditions. This difficulty poses considerable challenges because all elements of the 5×5 transformation matrix relating the field variables of one beam to those in another beam should be determined. The main contributions of the investigation are to propose additional necessary conditions to determine the matrix and to derive it exactly. The validity of the derived joint matching transformation matrix is demonstrated by showing good agreement between the shell finite element results and those obtained by the present box beam analysis in various angle box beams.

Geometric Nonlinearity Analysis of Composite Laminated Box Beam

2010 ◽  
Vol 168-170 ◽  
pp. 1999-2002
Author(s):  
Qiang Su ◽  
Ya Ping Wu
Keyword(s):  
Shear Deformation ◽  
Geometric Nonlinearity ◽  
Shear Lag ◽  
Finite Element Program ◽  
Box Beam ◽  
Analysis Theory ◽  
Element Program ◽  
Box Beams ◽  
Minimum Potential ◽  
Equivalent Nodal Forces

In this paper, the differential equations of composite laminated box beams are established based on the principle of minimum potential energy and the variational method. Considering shear lag and shear deformation effects, elastic stiff matrix, geometric nonlinearity stiff matrix and equivalent nodal forces vector of composite laminated box beam element are given. And a finite element program is developed, then a new computing analysis theory for composite laminated box beam is given, both considering shear lag, shear deformation and geometric nonlinearity effects.

Experimental Investigations of Shear Lag Effect in a Simply Supported [0o ∕±45o2 ∕ 0o]T Laminated Box Beam

2011 ◽  
Vol 117-119 ◽  
pp. 858-861
Author(s):  
Ya Ping Wu ◽  
Zhi Xiang Zha ◽  
Li Xia Wang ◽  
Yin Hui Wang
Keyword(s):  
Structural Engineering ◽  
High Efficiency ◽  
Experimental Investigations ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Normal Stress Distribution ◽  
Lag Effects ◽  
Box Beam ◽  
Lag Effect ◽  
Thin Walled

With the features of high efficiency, low consumption and good mechanical characteristic, thin-walled composite box beams have been broadly adopted in structural engineering, and its mechanical behavior has became an active research area. As shear lag effect can bring an uneven normal stress distribution on the flanges, it would remarkably affect the strength design of thin-walled beams. This paper focuses on the experimental investigations of shear lag effects in [0o∕±45o2∕ 0o]T laminated box beam under concentrated loads, and test results indicates that the shear lag effect in this composite box beam can be simulated by the two parabola.

Influence of Compression-Flexure to Shear Lag Effect of Box Beam

2011 ◽  
Vol 181-182 ◽  
pp. 857-860 ◽  
Author(s):  
Qiang Su ◽  
Ya Ping Wu
Keyword(s):  
Stiffness Matrix ◽  
Elastic Stiffness ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Finite Element Program ◽  
Box Beam ◽  
Lag Effect ◽  
Element Program ◽  
Box Beams ◽  
Minimum Potential

In this paper, the differential equations of box beams are established based on the principle of minimum potential energy and the variational method. The elastic stiffness matrix and geometric stiffness matrix considering shear lag and compression-flexure effects are induced in this paper. And a finite element program is developed. Then the influence of compression-flexure effects to shear lag effect of box beam is analyzed.

Finite Element Analysis on the Vibration Mode of Composite Thin-Walled Box Beam with Double-Cell Sections

2012 ◽  
Vol 569 ◽  
pp. 495-499
Author(s):  
Shuang Shuang Sun ◽  
Fang Wu Jia ◽  
Yong Sheng Ren
Keyword(s):  
Finite Element ◽  
Width Ratio ◽  
Finite Element Models ◽  
Modal Shape ◽  
Element Analysis ◽  
Finite Element Software ◽  
Box Beam ◽  
Box Beams ◽  
Length Width ◽  
Thin Walled

The modal analysis of composite thin-walled box beams with double-cell sections is carried out by the finite element software ANSYS. The finite element models are established first for the double-cell composite thin-walled box beams, then the vibration modes of two box beams: Circumferentially Uniform Stiffness (CUS) and Circumferentially Antisymmetric Stiffness (CAS) are calculated and analyzed. The effects of length-width ratio and width-height ratio on the natural frequency and the modal shape of the double-cell composite thin-walled box beams are discussed.

scholarly journals Nonlinear Buckling Analysis of Thin-Walled Box Beams considering Shear Lag

2020 ◽  
Vol 2020 ◽  
pp. 1-32
Author(s):  
Minyao Tan ◽  
Wenming Cheng
Keyword(s):  
Beam Theory ◽  
Shell Element ◽  
Beam Model ◽  
Shear Lag ◽  
Nonlinear Buckling ◽  
Lag Effects ◽  
Box Beams ◽  
Thin Walled ◽  
The Stability ◽  
Nonlinear Buckling Analysis

In this work, a general geometric nonlinear model of straight thin-walled box beams (STBBs) under combined eccentric and axial loads is established. In order to accurately reflect the behavior of STBB, the additional shear lag warping is added to enrich the displacement field. It is necessary to define the section shape function to describe the local section deformation. Therefore, extension, bending, torsion, distortion, and shear lag effects are expressed by the generalized coordinate method. Based on the stability of transverse unconstrained box beam theory, meaningful higher-order solutions can be obtained by defining a set of coupled deformation modes. The equilibrium equation is discretized by the Galerkin method, and the Newton–Raphson incremental method is used to derive and solve the nonlinear governing equations. On this basis, the analytical expression of stiffness matrix is established. For solving the stability problem, the effectiveness of the proposed method is verified by comparing the calculation results of shell element (Ansys) with other theories. Numerical examples even show that the proposed method can not only get the influence of shear lag but also obtain the variation of lateral buckling of the beam model.

Cyclic Loading of Piles Using the P-Y Method

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Matt Bristow
Keyword(s):  
Cyclic Loading ◽  
Soil Depth ◽  
Large Diameter ◽  
Reference Conditions ◽  
Numerical Procedure ◽  
New Method ◽  
Shear Stresses ◽  
Applied Loading ◽  
Cyclic Degradation ◽  
Laterally Loaded

A new analytical method is presented to determine the effects of cyclic loading on laterally loaded piles. The method uses a new numerical procedure to quantify the effects of the cyclic loading at each soil depth and convert that to a set of cyclic p-y modifiers. The reduced foundation stiffness associated with the cyclic loading can be determined, including the residual static capacity and an estimate of the accumulated displacement. The new method introduces the concept of cyclic degradation damage, which is defined as sum of the cyclic degradation that is occurring at each soil depth. Cyclic degradation calculations are based on the shear stresses in the soil. Consequently, anything that causes the shear stresses to change (e.g. pile length, pile diameter, applied loading, etc.) will automatically be included in the calculation of cyclic p-y modifiers. The method has been validated by comparing the cyclic p-y curves produced using the new method with established cyclic p-y curves derived from fielding testing. The new method has also been used to investigate what happens to the cyclic p-y modifiers as one moves away from the reference conditions used to determine the established cyclic p-y curves in API RP2A (2000). The new method shows that every application (e.g. combination of cyclic loading, pile properties, and soil characteristics) has its own unique set of cyclic p-y curves, though most p-y curves fit within an upper and lower bound range. Examples are provided for large diameter monopiles.

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