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Torsion of rectangular hollow tubes. Dan Peters & Huy Tao MCE 466 – Section 250 April 7, 2010. Background. Rectangular hollow sections (RHS) often used to resist twisting action i.e. space frames, edge beams, grillages, and gantry stanchions
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Torsion of rectangular hollow tubes Dan Peters & Huy Tao MCE 466 – Section 250 April 7, 2010
Background • Rectangular hollow sections (RHS) often used to resist twisting action • i.e. space frames, edge beams, grillages, and gantry stanchions • More efficient at resisting torsional loads than open sections
Theory of elastic torsional behavior of RHS • “thin wall” vs. “thick wall” • Marshall developed simplified equations for thick wall theory Torsional inertia constant: Torsional modulus constant: Mean perimeter: Area enclosed by mean perimeter:
Theory of elastic torsional behavior of RHS (cont’d) • Elastic torsional capacity is torque at which external surface begins to yield • Proportional to shear yield stress • Marks limit of linearity in torque-twist response Elastic torsional capacity: Magnitude of twist:
Laboratory torsion testing • Torsion testing apparatus comprised of fixed reaction beam and pivoted rotating beam • Torque created by matched pair of double acting hydraulic cylinders
Finite Element Analysis (FEA) • Four-noded shell elements (S4R) • Abaqus v6.9
Abaqus Modeling • Fixed at one end • Shell edge load
Abaqus Results • Mesh at 50 mm
Abaqus Results • Mesh at 10 mm
Abaqus Results • Mesh at 9 mm
Theoretical Vs. FEA • RHS 200 X 100 X 8 S275J2H • -5.1% error • RHS 200 X 100 X 8 S355J2H • -3.1% error
Reference • Ridley-Ellis, D.J., J.S. Owen, and G. Davies. “Torsional behaviour of rectangular hollow sections.” Journal of Constructional Steel Research 59 (2003) 641-663.