An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory

This paper presents analytical solutions for the buckling of thick beams. The Bernoulli-Euler beam theory (BEBT) overestimates their critical buckling load. This paper has derived a cubic polynomial shear deformation beam buckling theory (CPSDBBT) from first principles using the Euler-Lagrange diffe...

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Main Author: Charles Ike
Format: Article
Language:English
Published: Unviversity of Technology- Iraq 2024-01-01
Series:Engineering and Technology Journal
Subjects:
Online Access:https://etj.uotechnology.edu.iq/article_180926_8396301bf0334695626a6fbe9d6fc385.pdf
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author Charles Ike
author_facet Charles Ike
author_sort Charles Ike
collection DOAJ
description This paper presents analytical solutions for the buckling of thick beams. The Bernoulli-Euler beam theory (BEBT) overestimates their critical buckling load. This paper has derived a cubic polynomial shear deformation beam buckling theory (CPSDBBT) from first principles using the Euler-Lagrange differential equation (ELDE). It develops closed-form solutions to differential equations using the finite sine transform method. The formulation considers transverse shear deformation and satisfies the transverse shear stress-free boundary conditions. The governing equation is developed from the energy functional, Õ, by applying the ELDE. The domain equation is obtained as an ordinary differential equation (ODE). The finite sine transformation of the ODE transforms the thick beam, which is considered an algebraic eigenvalue problem. The solution gives the buckling load Nxx at any buckling mode n. The critical buckling load Nxx cr occurs at the first buckling mode and is presented in depth ratios to span (h/l). It is found that and agrees with previous solutions using shear deformable theories. For (a moderately thick beam), the Nxx cr is 2.50% lower than the value predicted using BEBT, confirming the overestimation by BEBT. The Nxx cr agrees with previous solutions, implying the shear deformation has been adequately accounted for, and the BEBT overestimates the Nxx cr. The value of Nxx cr found agrees with previous values in the literature.
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spelling doaj.art-89b32b8d581c443498bbd9526c53daab2024-02-04T18:01:22ZengUnviversity of Technology- IraqEngineering and Technology Journal1681-69002412-07582024-01-014219010310.30684/etj.2023.142505.1538180926An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam TheoryCharles Ike0Department of Civil Enginnering, Enugu State, University of Science And Technology - Nigeria, Agbani, Enugu State, Nigeria.This paper presents analytical solutions for the buckling of thick beams. The Bernoulli-Euler beam theory (BEBT) overestimates their critical buckling load. This paper has derived a cubic polynomial shear deformation beam buckling theory (CPSDBBT) from first principles using the Euler-Lagrange differential equation (ELDE). It develops closed-form solutions to differential equations using the finite sine transform method. The formulation considers transverse shear deformation and satisfies the transverse shear stress-free boundary conditions. The governing equation is developed from the energy functional, Õ, by applying the ELDE. The domain equation is obtained as an ordinary differential equation (ODE). The finite sine transformation of the ODE transforms the thick beam, which is considered an algebraic eigenvalue problem. The solution gives the buckling load Nxx at any buckling mode n. The critical buckling load Nxx cr occurs at the first buckling mode and is presented in depth ratios to span (h/l). It is found that and agrees with previous solutions using shear deformable theories. For (a moderately thick beam), the Nxx cr is 2.50% lower than the value predicted using BEBT, confirming the overestimation by BEBT. The Nxx cr agrees with previous solutions, implying the shear deformation has been adequately accounted for, and the BEBT overestimates the Nxx cr. The value of Nxx cr found agrees with previous values in the literature.https://etj.uotechnology.edu.iq/article_180926_8396301bf0334695626a6fbe9d6fc385.pdfccubic polynomial shear deformation beambuckling theoryfinite sine transformpotential energy functionaleuler-lagrange equationalgebraic eigenvalue problem
spellingShingle Charles Ike
An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory
Engineering and Technology Journal
ccubic polynomial shear deformation beam
buckling theory
finite sine transform
potential energy functional
euler-lagrange equation
algebraic eigenvalue problem
title An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory
title_full An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory
title_fullStr An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory
title_full_unstemmed An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory
title_short An Analytical Solution to Buckling of Thick Beams Based on a Cubic Polynomial Shear Deformation Beam Theory
title_sort analytical solution to buckling of thick beams based on a cubic polynomial shear deformation beam theory
topic ccubic polynomial shear deformation beam
buckling theory
finite sine transform
potential energy functional
euler-lagrange equation
algebraic eigenvalue problem
url https://etj.uotechnology.edu.iq/article_180926_8396301bf0334695626a6fbe9d6fc385.pdf
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