An Approximate Torsion Analysis of Closed Moderately Thick-Walled, Thick-Walled, and Solid Cross-Sections


Abstract: An approximated model and mathematical formulation are presented for the uniform torsion analysis of closed moderately thick-walled, thick-walled, and solid cross-sections. For this purpose, the considered section is ideally divided into thin-walled closed strips one inside the other. Using this model and Bredt's theory, the torsional moments carried by each strip are obtained. Then, considering that the number of the imaginary strips is sufficiently high, formulas are derived for the maximum shearing stress and the angle of twist of the considered cross-section. To demonstrate the accuracy and efficiency of the formulation, results for several cross-sections having exact or numerical solutions are presented. These results show that the formulation gives accurate values for solid and hollow sections with regular curvilinear contours. On the other hand, although for the thin-walled and moderately thick-walled sections there is high accuracy in the results, for the thick-walled and solid ones the accuracy decreases gradually. Thus, it is thought that the derived formulas can be useful especially for the analysis of a wide class of closed thin-walled and moderately thick-walled cross-sections subjected to torsional loading.

Keywords: Uniform torsion, Approximate analysis, Moderately thick-walled sections, Thick-walled sections, Solid sections

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