University of Illinois Urbana-Champaign

Analysis of torsional rigidity of intermittently stiffened I beam

Adams, D.F.

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https://hdl.handle.net/2142/111965

Description

Title
Analysis of torsional rigidity of intermittently stiffened I beam
Author(s)
Adams, D.F.
Issue Date
1963-05
Keyword(s)
  • Torsion
  • Rigidity
  • I Beams
Abstract
The torsional rigidity of a member having an open cross section can be increased by closing it in along part of its length. A thin-walled I cross section is considered, stiffener plates of arbitrary length being attached across the edges of the flanges at intervals to form closed sections. This intermittently stiffened I beam is analyzed as a member made up of open and closed sections joined together. The externally applied torque is assumed to be resisted at each cross section by a combination of pure torsional (St. Venant) shearing stresses and shearing forces associated with lateral bending. The lateral bending is a result of the difference in the warping characteristics of the open and the closed cross sections. Differential equations of equilibrium are derived for each section then solved to obtain expressions for the angle of twist per unit length. The necessary boundary conditions are established in order to evaluate the constants in these expressions. There are four variables to be considered in a particular problem: the geometry of the cross section, length of the stiffener plates, spacing between stiffener plates, and stiffener plate thickness. Numerical examples are presented for fifteen different configurations in which all of these variables are considered. The theoretical results are then verified experimentally. The extension of the general method of solution to other thin-walled, open cross sections is also discussed.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 246
  • 1967-0542
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/111965
Copyright and License Information
Copyright 1963 Board of Trustees of the University of Illinois

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Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.