2011 Research Reports
Books and Book Chapters - Journal Papers - Conference Papers
Higher Degree Theses
Click on the title of the research report to get the abstract and the download link for the PDF version of the report (if it is available)
Vinh Hua & Kim Rasmussen, Static Friction Coefficient Between Pallets and Beam Rail and Pallet Shear Stiffness Tests, Research Report No R914, March 2011.
Vinh Hua & Kim Rasmussen, The Dynamic Study of Drive-In Racks Under Horizontal Impact Load, Research Report No R915, March 2011.
Nicholas S Trahair, Wagners Beam Cycle, Research Report No R916, March 2011.
Xi Zhang, Kim Rasmussen & Hao Zhang, Formulation and implementation of three-dimensional doubly symmetric beam-column analyses with warping effects in OpenSees, Research Report No R917, July 2011.
Gregory J Hancock & Cao Hung Pham, A Signature Curve for Cold-Formed Channel Sections in Pure Shear, Research Report No R919, July 2011.
Nicholas S Trahair, Inelastic Buckling of Monosymmetric I-Beams, Research Report No R920, September 2011.
Nicholas S Trahair, Strength Design of Cruciform Steel Columns, Research Report No R921, October 2011.
Vinh Hua & Kim Rasmussen
Static Friction Coefficient Between Pallets and Beam Rail and Pallet Shear Stiffness Tests
Research Report No R914, March 2011.
Abstract:
An experimental program was established at the University of Sydney to determine the coefficient of friction between various types of timber pallets and a typical Dematic beam rail. In addition, another test series was also carried out to measure the shear stiffness of those timber pallets. The outcome of the study can be used as a guideline for further design enhancement of the drive-in rack system. This report summarizes the test results and their possible implementations.
Keywords: Drive-in racks, steel storage racks, steel structures, finite element analysis, friction coefficient, shear stiffness.
Full Report in PDF (8.39 MB)
Vinh Hua & Kim Rasmussen
The Dynamic Study of Drive-In Racks Under Horizontal Impact Load
Research Report No R915, March 2011.
Abstract:
This report is concerned with the behaviour of drive-in steel storage racks under horizontal impact load in the down-aisle direction. Such impact loads due to forklifts striking an upright is a major cause of structural failure for drive-in rack systems.
The report investigates investigate the dynamic behaviour of a standard drive-in rack subjected to a down-aisle impact load. The effect of damping ratio, masses carried by the rack as well as the friction between the pallet and the rail track are investigated for impulse loading
Keywords: Drive-in racks, steel storage racks, steel structures, dynamic, finite element analysis, design
Full Report in PDF (2.25 MB)
Nicholas S Trahair
Wagners Beam Cycle
Research Report No R916, March 2011.
Abstract:
This paper summarises a number of research studies on the torsion and buckling behaviour of beams which derive from a theory developed by Wagner, who extended Timoshenko’s treatment of the elastic buckling of I-section beams and columns to members of general thin-walled open cross-section. These studies include applications of the first-order Wagner theory to the buckling of beams and cantilevers, and of the second-order Wagner theory to the large rotations and post-buckling behaviour of beams.
Keywords: Beams, bending, buckling, large rotations, post-buckling, steel, thin-walled sections, torsion.
Full Report in PDF (268 kB)
Xi Zhang, Kim Rasmussen & Hao Zhang
Formulation and implementation of three-dimensional doubly symmetric beam-column analyses with warping effects in OpenSees
Research Report No R917, July 2011.
Abstract:
OpenSees is an object-oriented framework for finite element analysis. A key feature of OpenSees is the ability to integrate existing libraries and new components into the framework without the need to change the existing code. The non-linear beam-column element theory in OpenSees is based on the assumption that torsion is uniform through the length of the member and non-uniform warping torsion is excluded. In this report, a corotational mapping for three-dimensional analyses of doubly symmetric beam-column elements with warping effects is incorporated into OpenSees. Both a local linear strain assumption and a second order approximation of the Green-Lagrange strains are considered in the formulations of the beam elements at local level. Numerical examples are presented to demonstrate the accuracy of the proposed elements by comparisons with results from the literature and commercial softwares.
Keywords: Co-rotational formulation, Warping, OpenSees, Thin-walled structures.
Full Report in PDF (800 kB)
Opensees Source Code as RAR achive (98 MB)
Gregory J Hancock & Cao Hung Pham
A Signature Curve for Cold-Formed Channel Sections in Pure Shear
Research Report No R919, July 2011.
Abstract:
Thin-walled sections in compression and/or bending may undergo one of the three modes of local, distortional or overall (Euler) buckling, or combinations of these. The Semi-Analytical Finite Strip Method (SAFSM) developed by YK Cheung has been widely used in computer software (THIN-WALL, CUFSM) to develop the signature curve of the buckling stress versus buckling half-wavelength for a thin-walled section under compression or bending to allow identification of these modes. The minimum points on the signature curve are now used in the Direct Strength Method (DSM) of design of cold-formed sections in the American Specification and Australian/New Zealand Standard for cold-formed steel structures.
Plank and Wittrick (1974) included shear in the SAFSM theory for calculating the stiffness and stability matrices by using complex mathematics. The complex mathematics is needed to allow for the phase shifts in the buckling modes (eigenvectors) for sections under shear.
This paper summarises the theory then applies it to the buckling of channel sections in pure shear. Signature curves for shear are developed for channel sections and compared with classical solutions, and those produced by the Spline Finite Strip Method (SFSM) previously published by the authors. The effect of including a web stiffener on the signature curve and buckling modes is demonstrated.
Keywords: Cold-formed channel sections; Signature curve; Buckling analysis; Complex mathematics; Finite strip method; Shear buckling; Spline finite strip method.
Full Report in PDF (2000 kB)
Nicholas S Trahair
Inelastic Buckling of Monosymmetric I-Beams
Research Report No R920, September 2011.
Abstract:
Methods of designing steel monosymmetric I-beams against lateral buckling are not well supported by research. For this paper, the inelastic buckling of monosymmetric steel I-beams under moment gradient was studied and compared with design recommendations.
For welded beams in uniform bending, inelastic buckling is initiated at moments which are often close to those which cause first yield in the compression flange. Once initiated, the inelastic buckling resistance remains constant as the slenderness decreases until strain-hardening occurs. For hot-rolled beams in uniform bending, the inelastic buckling resistance increases almost linearly as the slenderness decreases.
Three regimes are significant in the inelastic buckling resistances of hot-rolled monosymmetric beams under moment gradient, depending on which flange yields first and the end moment ratio.
Simple linear approximations of good accuracy were developed for designing hot-rolled monosymmetric beams in uniform bending, while less accurate but conservative approximations were developed for moment gradient. The use of these approximations was illustrated by a worked example.
Keywords: Beams, bending, buckling, design, inelastic, monosymmetry, steel, yield.
Full Report in PDF (185 kB)
Nicholas S Trahair
Strength Design of Cruciform Steel Columns
Research Report No R921, October 2011.
Abstract:
Very different strengths are predicted by two different methods of designing steel cruciform columns. Both methods require design against local and flexural buckling, and while one method also requires design against torsional buckling, the other does not.
Investigations of the elastic local and torsional buckling and post-buckling of cruciforms columns show that these two modes are virtually identical.
The first yield and inelastic buckling approaches often used to formulate methods of designing columns against flexural buckling are extended to the torsional buckling design of cruciforms. These extensions show that it is sufficient to use local buckling design to guard against torsional buckling.
It is found that design methods which make separate checks against local and torsional buckling are unnecessarily severe, and are equivalent to making the same strength reduction twice. Instead, it is sufficient to ignore the torsional buckling of cruciforms provided design checks are made against local buckling as well as flexural buckling.
Keywords: Buckling, Columns, Cruciforms, Design, Flexure, Post-buckling, Steel, Torsion, Yield
Full Report in PDF (121 kB)