Can supervise: YES
Structural Mechanics, Finite Element Analysis, Computational Mechanics
Saleh, A 2008, Structural Analysis, 2008, Self, Sydney.
Classical methods of structural analysis. Theory and solved problems. Topics include: Review of fundamentals in Statics. Principle of Work and Virtual Works. Computation of elastic deformation. Influence Lines. Force Method. Moment Distribution method.
Far, H, Firouzianhaji, A & Saleh, A 2019, 'A Simplified Method to Determine Shear Stiffness of Thin Walled Cold Formed Steel Storage Rack Frames', Journal of Constructional Steel Research, vol. 156.View/Download from: Publisher's site
Lin, X, Far, H & Saleh, A 2019, 'Structural Behaviour and Mechanical Properties of Welded Steel I-Girders with Corrugated Webs', International Journal of Steel Structures, vol. 19, no. 4, pp. 1342-1352.View/Download from: Publisher's site
Steel I girders with corrugated webs are appropriate alternatives for normal flat-web girders in steel structures since they provide lighter and smaller beam features in steel design. Based on the existing literature, the corrugated web beams (CWBs) provide many advantages for structural applications. In this study, a series of numerical analyses have been performed in order to investigate the structural behaviour of steel I girders with corrugated web profile and to compare their mechanical performance with normal welded beams. Theory of Ultimate Limit State design has been adopted in accordance with AS4100 (1998) along with considering geometric and material non-linearity in the numerical analyses in SAP2000. Comparing the results of the numerical investigation, merits of using corrugated welded beams (CWBs) over normal welded beams (WBs) have become apparent. Moreover, investigations regarding force-displacement relationship and buckling analysis of the webs were carried out and presented to further validate the advantages of using corrugated web beams. CWBs have been used in some parts of Australia without detailed information about their mechanical properties. Thus, based on the outcomes of this study, CWB table for dimensions and cross sectional properties has been developed and proposed for practical applications.
Haydar, H, Far, H & Saleh, A 2018, 'Portal Steel Trusses vs. Portal Steel Frames for Long- span Industrial Buildings', Steel Construction, vol. 11, no. 3, pp. 205-217.View/Download from: Publisher's site
Portal frames and portal truss structures are two of the most cost effective and sustainable structural commodities for utilisation in the design and construction of long span industrial buildings. Although the application of both structure types as steel cladded structures is widely accepted, due to frame complexity and variation of frame types for use in single story buildings, that exceed spans greater than 30 meters, literature providing a comprehensive investigation on the concepts of portal trusses and portal frames is scarce. This study compares the behaviour of portal truss configuration with pitched portal frames for use in long span industrial buildings that exceed 30 meters with focus on weight, costs and time for construction. Furthermore, this study entails a numerical investigation that utilises SAP2000 computer program to model and structurally optimise the member properties for both portal frame and portal truss configurations. Based on the results obtained from the investigation, it has become apparent that the portal truss configurations are lighter and cheaper to fabricate and construct due to the smaller sections used in comparison to the pitched portal frame that require a shorter time for construction.
Saleh, A, Far, H & Mok, L 2018, 'Effects of Different Support Conditions on Experimental Bending Strengthof Thin Walled Cold Formed Steel Storage Upright Frames', Journal of Constructional Steel Research, vol. 150, pp. 1-6.View/Download from: Publisher's site
Walsh, P, Saleh, A & Far, H 2018, 'Evaluation of Structural Systems in Slender High-rise Buildings', Australian Journal of Structural Engineering // the Institution of Engineers, Australia, vol. 19, no. 2, pp. 105-117.View/Download from: Publisher's site
With the rapid population growth and scarcity of developable space, especially in large cities, there is a need for increased density in both commercial and residential housing, and hence a strong demand to maximise floor space by constructing not only tall, but also slender buildings. This study considers different structural systems available for constructing slender high-rise buildings and evaluates their feasibility in terms of the lateral deformation being one of the key governing design criteria for very tall buildings. To examine the performance of different structural systems in buildings of varying height and floorplan, this study applies finite element analyses in a parametric study to compare nine different building configurations under static loading with heights varying from 80m to 460m. The study shows that buildings with square footprints can achieve greater heights over rectangular footprints with the same area and that multiple towers when connected structurally at one or more levels can achieve even greater heights.
Erkmen, RE & Saleh, A 2017, 'Iterative global-local approach to consider the effects of local elasto-plastic deformations in the analysis of thin-walled members', International Journal for Multiscale Computational Engineering, vol. 15, no. 2, pp. 143-173.View/Download from: Publisher's site
© 2017 by Begell House, Inc. The aim of this study is to develop an iterative global-local analysis method to efficiently model the local deformation effects for the nonlinear elasto-plastic analysis of thin-walled beams. Thin-walled members are usually modeled by using beam-type one-dimensional finite elements, which are based on rigid cross-section assumption. Therefore, only deformations associated with the beam axis behavior such as flexural-, torsional-, or lateral buckling can be considered in these formulations, whereas local deformations, namely flange or web local buckling, can be captured by shell-type models. The proposed method allows the local use of shell elements in critical areas to incorporate the local deformation effects on the overall behavior of the thin-walled beam without necessitating a shell model for the whole structure. In this study, the local shell formulation is able to capture the elasto-plastic metal behavior based on the von Mises yield criterion and the associated flow rule for plane stress, which may cause unstable post-buckling response. In order to trace an unstable post-buckling curve, the iterative global-local analysis method is incorporated into the arc-length solution procedure. In order to improve the convergence characteristics, the procedure introduces strong discontinuities in the beam element formulation in the region of the local shell elements. These discontinuities are in the form of an internal enrichment considering additional local degrees of freedom associated with some penalty terms which adjust the tangent stiffness matrix of the beam for the prediction in the next step according to the effects of the local shell model in the previous step. Comparisons with full shell-type analysis are provided in order to illustrate the accuracy and efficiency of the method developed herein.
Far, H, Saleh, A & Firouzianhaji, A 2017, 'A Simplified Method to Determine Shear Stiffness of Thin Walled Cold Formed Steel Storage Rack Frames', Journal of Constructional Steel Research, vol. 138, pp. 799-805.View/Download from: Publisher's site
The shear stiffness of braced frames of thin-walled cold-formed steel storage racks was experimentally and numerically investigated in order to establish the effect of connection flexibility on the accuracy of different analysis methods. The analyses which included a detailed 3D Finite element model, a 2D frame analysis with beam elements and a simple hand calculation indicated significant variation of results compared with experimental values. A simplified modelling approach for 2D elastic analysis of braced frames was proposed. The approach is aimed at practical applications to account for the flexibility in bolted connections and leads to better approximation of the shear stiffness.
Erkmen, RE, Saleh, A & Afnani, A 2016, 'Incorporating Local Effects In The Predictor Step Of The Iterative Global-Local Analysis Of Beams', International Journal for Multiscale Computational Engineering, vol. 14, no. 5, pp. 455-477.View/Download from: Publisher's site
The aim of the study is to develop a stiffness modification technique that considers the effects of local deformations/damages within the predictor step of iterative global-local analysis. The procedure is based on internal springs introduced in a beam element formulation whose constants are obtained according to the force vs. displacement results of the global-local analysis. Within the beam element formulation, strong discontinuities are introduced in the form of an internal enrichment considering additional local degrees of freedom associated with the deformations of local springs. Determination of the spring constants introduced in this study is an inverse problem, as given independent end-displacements and end-forces, corresponding spring stiffness terms are sought. Discussions on the heuristic nature of this problem are included and a regularization option is introduced to give rise to a unique solution for the problem. Nevertheless, it is shown that by using the proposed approach the number of iterations can be significantly reduced within the iterative global-local analysis algorithm. In the corrector step of the global-local analysis a local membrane finite element model is used to obtain the internal stress field.
Aoki, Y, Valipour Goudarzi, H, Samali, B & Saleh, A 2013, 'A Study on Potential Progressive Collapse Responses of Cable-Stayed Bridges', Advances in Structural Engineering, An International Journal, vol. 16, no. 4, pp. 689-706.View/Download from: Publisher's site
In this paper, a finite element (FE) model for a cable-stayed bridge designed according to Australian standards is developed and analysed statically and dynamically with and without geometrical nonlinearities. The dynamic amplification factor (DAF) and demand-to-capacity ratio (DCR) in different structural components including cables, towers and the deck are calculated and it is shown that DCR usually remains below one (no material nonlinearity occurs) in the scenarios studied for the bridge under investigation, however, DAF can take values larger than two. Moreover, effects of location, duration and number of cable(s) loss as well as effect of damping level on the progressive collapse resistance of the bridge are studied and importance of each factor on the potential progressive collapse response of the bridgeis investigated.
When modelling composite or built up beams using finite element software, analysts find it often convenient to connect two standard EulerâBernoulli beam elements at the nodes by using a rigid bar or use masterâslave type kinematic constraints to express the degrees-of-freedoms of one of the members in terms of the other. However, this type of modelling leads to eccentricity related numerical errors and special solutions that avoid eccentricity related issues may not be available for a design engineer due to the limitations of the software. In this study, a simple correction technique is introduced in the application of masterâslave type constraints. It is shown that the eccentricity related numerical errors in the stiffness matrix can be completely corrected by using extra fictitious elements and springs. The correction terms are obtained by using the exact homogenous solution of the composite beam problem as the interpolation functions which impose the zero-slip constraint between the two components in the point-wise sense. The effects of the eccentricity related errors are demonstrated in numerical examples.
Saleh, A & Parsanejad, S 1996, 'Application of orthogonalised load/deflection states to the collapse behaviour of grout-filled damaged tubular members', STRUCTURAL ENGINEERING REVIEW, vol. 8, no. 2-3, pp. 269-275.
Sedlacek, G, Lopetegui, J, Stutzki, C & Saleh, A 1985, 'Computer Aided Analysis of Space Frames Subjected to Nonlinear Loads.', Bauingenieur Berlin, vol. 60, no. 8, pp. 297-306.
Two approaches in design of space frame structures are outlined and discussed. The kinematic equations for arbitrary large rotation of beams are formulated by means of rotation vectors. This is the so called displacement method. The other approach uses nonlinear computational algorithms. An iteration procedure was developed using initial stiffness matrix and orthogonal load-deformation-states.
Aoki, Y, Valipour, H, Samali, B & Saleh, A 2014, 'Sensitivity Analysis For Steel Deck Of A Cable-Stayed Bridge Subjected To Blast Loadings', Proceedings of the 23rd Australasian Conference on the Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, Southern Cross university, Byron Bay, Australia, pp. 1039-1044.
In design of cable-stayed bridges, sudden loss of cables are usually associated with material as well as
geometrical nonlinearities which may trigger progressive collapse of the entire bridge. Accordingly,
the possible reasons of loss of cable would be the blast loadings, which is one of the concerned
situations after 911 terrorist attacks. In this paper, detailed 3D finite element models of a hypothetical
cable-stayed bridge deck is developed and analysed with material and geometrical nonlinearities
included. A parametric study is undertaken to investigate the effect of blast loadings with different
material properties, section properties and different amount of explosive materials, to determine
damaged area, number of loss of shell elements as well as cable elements due to explosion. With
regard to the results of FE analysis, it is concluded that the maximum 3 cables would be lost by the
large amount of TNT equivalent material due to damage of the anchorage zone.
Firouzianhaji, A, Saleh, A & Samali, B 2014, 'Non-Linear Finite Element Analysis Of Base-Plate Connections Used In Industrial Pallet Rack Structures', Proceedings of Australasian Structural Engineering Conference 2014, Australasian Structural Engineering Conference, ASEC, Auckland, NZ, pp. 1-9.
This paper presents the results of experimental and FE simulations of a typical base plate connection used for industrial storage racks with two different floor anchoring configurations. The experimental results presented provide moment rotation curves of the base plates for 5 different axial loads imposed on the upright. The experimental setup models the same structural conditions stipulated in EN 15512 but with an alternative test rig setup that overcomes some drawbacks of the test arrangement proposed in EN 15512. Using FE models that incorporate material, geometric and contact non-linearity, the base plates were analysed for both monotonic and cyclic loading.
Firouzianhaji, A, Saleh, A & Samali, B 2014, 'Stability Analysis of Steel Storage Rack Structures', Proceedings of the 23rd Australasian Conference on the Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, Southern Cross University, Byron Bay, Australia, pp. 583-588.
Aoki, Y, Samali, B, Saleh, A & Valipour Goudarzi, H 2012, 'Assessment of key response quantities for design of a cable-stayed bridge subjected to sudden loss of cable(s)', From materials to structures: Advancement through innovation, Australasian Conference on the Mechanics of Structures and Materials, CRC press/Balkema, Sydney, Australia, pp. 387-392.View/Download from: Publisher's site
Stays of cable-stayed bridges have potential to lose their support instantly by extreme loadings such as earthquake, thunder strike, vehicle impact, wind and malicious attacks. The sudden loss of cable(s) provides unpredictable stress redistribution on the deck and towers, as well as the large deflections of the entire bridge. This phenomenon is the cause of one of the most critical situations for the cable-stayed bridges, termed âzipper-type collapseâ (i.e. the mechanism of the progressive collapse by the redistribution of stresses). Considering such a sudden loss of cable in the design of a cable-stayed bridge is essential. Although cable loss scenarios are associated with material as well as geometrical nonlinearities, in design of cable-stayed bridges, such an extreme loading scenario is analysed typically by using linear elastic models. In this paper, a linear elastic 2D and a fully nonlinear 3D finite element model of an idealised steel cable-stayed bridge are developed and analysed to determine the effect of sudden loss of cable on the progressive collapse of the bridge at global and local stress levels.A parametric dynamic analysis for the bridge model with different cable loss scenarios under symmetrical or unsymmetrical load cases is investigated. The bridge model studied in this paper showed that the 2D model can adequately capture global behaviour of the bridge. The 3D model showed the most significant stress concentration occurring under the symmetrical case are limited to small areas and are negligible.
Firouzianhaji, A, Saleh, A & Samali, B 2012, 'Finite element modeling of a beam-column connection in industrial storage racking structures', From materials to structures: Advancement through innovation - 22nd Australian Conference On The Mechanics Of Structures And Materials, Australasian Conference on the Mechanics of Structures and Materials, CRC press/Balkema, Sydney, Australia, pp. 813-818.View/Download from: Publisher's site
Industrial storage racking structures are typically constructed using cold-formed steel sections and contain moment resisting frames in which the columns have slots punched in at regular intervals to enable the beams to be clipped into position at any desired high. Hence unlike in conventional steel construction the beam to column connections are typically not bolted or welded but rely primarily on hooks and bearing contact between components to achieve the connection. As a consequence, such connections are semi-rigid and when loaded to failure they exhibit non-linear stiffness characteristics that are attributed to both geometric and material non-linearity. Due to the slenderness and flexibility of industrial racks, it is important therefore to consider the effect of connection flexibility when preparing structural models of such racking systems. A research project is currently underway at University of Technology, Sydney to investigate the behaviour of such connections and its effect on the dynamic response of industrial storage racking systems. An important part of this research, which is the focus of this paper, is devising suitable finite element models of the connections and verifying their accuracy against experimental moment-rotation curves. By considering the real conditions that govern the connection response, the FE models include different features such as 3D geometric details, non-linear material behavior, large displacements and the phenomena of contact non-linearity. This paper presents finite element models of a typical beam-column connection used in industrial storage racking structures and compares their accuracy against experimental results. The computational effort required in the analysis of different modeling options will also be compared and the adequacy in incorporating the model in a dynamic/Seismic finite element analysis will be discussed.
Aoki, Y, Samali, B, Saleh, A & Valipour Goudarzi, H 2011, 'Impact of sudden failure of cables on the dynamic performance of a cable-stayed bridge', The Austroads 8th Bridge Conferences - Sustainable Bridges: The Thread of Society - proceedings Volume II, Austroads Bridge Conference, Austroads Incorporated, Sydney, Australia, pp. 310-321.
In cable stayed bridges corrosion and fatigue as well as extreme loadings such as earthquake, lightning strike and blast may lead to loss of cables. The vulnerability of cable stayed bridges for such cable loss scenarios has not been thoroughly investigated yet and is not considered in the current design practice. Accordingly, in this paper a primary study on vulnerability of cable stayed bridges against such extreme scenarios is undertaken. A two-dimensional Finite Element (FE) model of a cable-stayed bridge is developed in ANSYS. The mid-span of the bridge studied in this paper is 600 meter long and made of a steel box. The bridge is supported by two 140 meter tall steel towers and 56 steel cables. The bridge is analysed for two different cable loss scenarios and the global response of the structure (i.e. deformation of the bridge, bending moment at mid-span of the deck and the base of the tower, and axial force for deck and each cable) following the cable loss scenarios are studied. Further, dynamic amplification factors (DAF) for deflections and internal forces are determined by comparing the results of static analysis with the results obtained from transient dynamic analysis.
Saleh, A, Li, J & Lucas, J 2011, 'Internet-hosted assessment system for effective teaching and enhanced learning for engineering subjects', Proceedings of the 22nd Annual Conference for the Australasian Association for Engineering Education (AAEE2011) - Developing Engineers for Social Justice: Community Involvement, Ethics & Sustainability, AAEE - Annual Conference of Australasian Association for Engineering Education, Engineers Australia, Fremantle, WA, pp. 505-509.
Despite of their popularity, online Learning Management Systems suffer serious limitations as a reliable and effective assessment tool in their implementation for engineering education, partly due to their demand for equation manipulation and multiple stage problem solving. An innovative spreadsheet based assessment tool (e-Task) which is designed to overcome such shortcoming and provides effective teaching and enhanced learning for engineering subjects has been proposed by the authors. The tool was developed for both formative and summative assessments with a capability to automatically collect not only results but also feedback from students on their perceived learning. Building on the previous work, this paper presents a further development by introducing a new deployment concept of the e-Task through internet-hosting of the system in order to enable effective teaching and enhanced learning of engineering subjects. The proposed internet-hosted assessment system (e-Task) integrates state-of-the-art cloud computing technology by incorporating a spreadsheet-like environment that can accommodate a wider range of users and course developers as well as enables easier expansion of the system in the future. It greatly enhances the fundamental concepts proposed in the original e-Taks by offering better accessibility, flexibility and controllability. It obviates any need of a specific software or hardware for the operational platform and requires only Internet access for its operation. Features of the Internet hosted e-Task include: the ability to access it by various Internet browsers, embedding learning and diagnostic feedback, individualised data sets for each students and automated marking & feedback.
Saleh, A & Li, J 2010, 'Innovative Assessment and Feedback System for Structural Engineering Education', Proceedings of the 21st Annual Conference for the Australasian Association for Engineering Education, Annual Conference of Australasian Association for Engineering Education, University of Technology, Sydney, Sydney, Australia, pp. 315-321.
Commercial Online course management platforms are increasingly used in teaching and learning in many disciplines. However their use for setting assessment tasks in engineering education is often difficult and limited in achieving desired teaching and learning objectives. This is partly due to the nature of engineering exercise problems which often requires equation manipulation and multi-stage problem solving. This paper presents an innovative spreadsheet based tool which is designed to cater for this type of problem. The tool was developed for both formative and summative assessments and with a resource optimal capability to automate both marking and collecting timely feedback from students on their perceived learning. It aims to encourage active learning with activatable hints and to minimise plagiarism by generating individual assignment data for each student.
Saleh, A & Gardner, AP 2009, 'Digital animations as a visual learning tool for Structural Analysis', Proceedings of the 20th Australasian Association for Engineering Education Conference, Annual Conference of Australasian Association for Engineering Education, The School of Mechanical Engineering, The University of Adelaide, Adelaide, Australia, pp. 229-236.
A number of digital animation clips have been developed to explore the effectiveness of their use in teaching of the subject Structural Analysis at the University of Technology, Sydney.The subject Structural Analysis is perceived by most students as challenging not only because of the theory and analysis concepts covered, but also because in its application it is difficult to visualise how structures behave when subjected to loads. The animation clips that were developed bring âmovement and lifeâ to structures that are traditionally presented in textbooks as static. It is anticipated that this will assist students to visualise the behaviour of structures and to better understand difficult concepts and methods taught in the subject. The intended uses of the animations are (1) in-class demonstration of behaviour of structures and methods of structural analysis and (2) as a self learning tool for students. This paper will present examples of the animations, how they have been used in teaching of Structural Analysis and feedback from students on their effectiveness.
Saleh, A & Mok, L 2007, 'Four Point Bending Tests on rack Upright Frames with Two Different Support Conditions', Proceedings of the 6th International Conference on Steel and Aluminium Structures, 6th International Conference on Steel and Structural Engineering, Thomas Telford Ltd, Oxford, United Kingdom, pp. 1-8.
Upright frames are a primary structural component in industrial racking systems. They are typically composed of two perforated thin-walled members that are linked together by a bracing system. Design computations in accordance with current industry standards rely in part on laboratory testing. One of these tests is for determining the bending strength of an upright section and is the subject of this paper. When testing the bending strength about the major axis of the upright, a four-point bending test of the assembled upright frame is made. The test arrangement prescribed by the standard must permit free twisting of the section at the supports, while the applied loads and their reactions for each upright may be applied in the plane of the sectionâs shear centre. Laboratory testing of two sets of upright frames, loaded through the uprightâs shear centre but with each set having a different support condition indicated that free twisting at the supports had only little influence on the bending capacity of the upright member. This paper outlines the test setup and reports the results in form of characteristic load deformation curves of the tested specimen.
Samali, B, Bakoss, SL, Li, J, Saleh, A & Wije, A 2003, 'Assessing the Structural Adequacy of a 3-span Steel-Concrete Bridge Using Dynamic Methods: A case study', Abstracts of the Tenth International Conference: Structural Faults & Repair Abstracts, ENGINEERING TECHNICS PRESS, London, UK.
SALEH, A & STUTZKI, C 1991, 'APPLICATION OF LARGE DEFLECTION THEORY TO THE STABILITY ANALYSIS OF LATTICE SHELLS', COMPUTATIONAL MECHANICS, VOLS 1 AND 2, ASIAN PACIFIC CONF ON COMPUTATIONAL MECHANICS ( APCOM ), A A BALKEMA, HONG KONG, HONG KONG, pp. 53-57.