Non-Linear Analysis and Design of Perforated Thin-walled Steel Strutures

Introduction
Perforated thin-walled steel structures are widely used, however, current design guidelines for them are limited to very few specific cases.
The seminar will try to describe a proposed method to develop new design guidelines for this kind of structures by using the Direct Strength Method (DSM) which is a fast and easy design method for cold-formed steel structures, with great potential for complex and optimized cross sections.

Based on the recently developed Isoparametric Spline Finite Strip Method (ISFSM) which has been proved to be an efficient and suitable mechanics-based numerical tool for analysing thin-walled structures with holes, analyses which incorporate both geometric and material nonlinearity are going to be carried out for a realistic prediction of strength that can be used in design.
Exploring Emergency Response coordination through complex adaptive systems
Exploring Emergency Response coordination through complex adaptive systems

Introduction
Traditional studies on coordination emphasised more stable and hierarchical environment and therefore is not suitable for explaining the coordination for dynamic and complex environment such as Emergency Response Coordination (ERC). In this study, we draw on coordination theory and network concepts to explore the problem of effective ERC. We argue ERC is dynamic and complex and therefore needs to have the characteristics of Complex Adaptive Systems (CAS) for it to be effective. We suggest the usefulness of social networks based approach to explore ERC problems and develop a social networks based coordination model for ERC in terms of complex networks. We argue that emergency response coordination is dynamic and complex and therefore needs to have the characteristics of adaptive systems for it to be effective. We apply complex adaptive system theory to explore the coordination process in an emergency situation.

Traditional studies on coordination emphasised more stable and hierachical environment and therefore is not suitable for explaining the coordination for dynamic and complex environment such as emergency response coordination.

Our aim here is to (i) explore and summarise the existing research on coordination theory; (ii) apply the existing coordination theory for dynamic and complex environment; (iii) suggest the usefulness of social networks based approach to explore emergency response coordination problem; (iv) develop a social networks based coordination model for ERC and suggest possible hypothesis for testing the model; (v) explore the emergency response coordination dataset to test the hypothesis; and (vi) apply CAS (complex adaptive systems) theory to further explain the observed behavior.

We ask the following questions: What are the limitations of existing coordination theory for exploring dynamic and complex coordination such as ERC? What is the relationship between social networks and coordination and in particular, how can coordination problem in unstable and dynamic situation can be explored by social networks analysis? How useful is the CAS to explain the emergency response coordination behavior?
Measuring Coordination Gaps of Open Source Groups through Social Networks
Measuring Coordination Gaps of Open Source Groups through Social Networks

Introduction
We argue that coordination gaps, such as communication issues and task dependencies have significant impact on performance of work group. To address these issues, contemporary science suggests optimising links between social aspects of society and technical aspects of machines. The contribution of this paper fall into three categories. Firstly, a framework is proposed to describe social network structure and coordination performance variables with regards to distributed coordination during bug fixing in the Open Source domain.

Based on the model and the literature reviewed, we propose two propositions:

(i) level of interconnectedness has a negative relation with coordination performance; and,
(ii) centrality social network measures have positive relation with coordination performance variables.

We provide empirical analysis by using a large sample of 415 open source projects hosted on SourceForge.net. The results suggest that there is relationship between interconnectedness and coordination performance and centrality measures were found to have positive relationships with the performance variables of coordination measures.
Multiscale Model-Based Simulation of Material and Structural Failure
Multiscale Model-Based Simulation of Material and Structural Failure

Introduction
Modern engineering problems are challenging and multiscale in nature. In many cases, the physical phenomena operate across10-12 orders of magnitude in spatial and/or temporal scales. The conventional single level simulation method which is valid only for limited ranges of spatial and temporal scales is not able to capture the whole picture. Multiscale simulation approaches that integrate nano-, micro- and macro-mechanics are needed in order to bridge the different length and time scales involved in the material and structural failure process. In this presentation, the potential of multiscale simulation methods will be demonstrated through three recent studies, namely, 1) simulation of tungsten thin film delamination from silicon substrate by combining the material point method (MPM) and molecular dynamics (MD), 2) numerical investigation of the grain size and nitrogen-doping effects on the mechanical properties of ultrananocrystalline diamond with a combined kinetic Monte Carlo (KMC) and MD approach, and 3) simulation of glass fragmentation under impact using a bifurcation-based decohesion model with the MPM. In addition to the brief introduction to the MPM, KMC and MD, the implementation of the proposed multiscale approaches will be discussed. Numerical findings from each study will then be presented. Future research topics that aim to promote the application of nanotechnology in the civil and environmental engineering will be proposed at the end.
Nondeterministic Linear Static Finite Element Analysis: An Interval Approach
Nondeterministic Linear Static Finite Element Analysis: An Interval Approach

Introduction
This research presents a nontraditional treatment for uncertainties in the material, geometry, and load parameters in linear static finite element analysis for mechanics problems. Uncertainties are introduced as bounded possible values (intervals). The major difficulty associated with interval computation is the dependence problem, which results in severe overestimation in the system response ranges. Particular attention in the development of the present method is given to control the dependence problem. The developed method is based on an Element-By-Element technique. The penalty method is used to impose the necessary constraints for compatibility and equilibrium. The standard fixed point iteration is modified, enhanced, and used to solve the interval system equations accurately and efficiently. Special algorithms have been developed to calculate accurate results for stress and element nodal force. The present method is generally applicable to linear static interval FEA, regardless of element type. Numerical examples are presented to demonstrate the capabilities of the developed method. In addition to its accuracy, rigorousness and scalability, the efficiency of the present method is also significantly superior to previous methods such as the sensitivity analysis and the Monte Carlo sampling method.
DEM Simulation of Quasi Static Behaviour of Granular Materials
DEM Simulation of Quasi Static Behaviour of Granular Materials

Introduction
The vast majority of current experimental research in soil mechanics is focused on axisymmetric compression tests. Even though plane strain deformation is a close approximation to many geotechnical engineering problems there is very little work devoted to examining the plane strain response of granular media. Although the general case in geotechnical engineering problems is one in which s1 .NE. s2 .NE. s3 there is probably less than ten research groups worldwide that have facilities for "true triaxial testing". Although the tradition is that theory is tested by experiment it is not clear whether such complex "true" triaxial apparatuses provide entirely reliable results. An alternative is to numerically simulate complex loading paths in general 3D stress space.

The presentation will show results of 3D Discrete Element Method (DEM) simulations in which radial deviatoric straining is applied and the corresponding stress response envelopes are shown to correspond to Lade surfaces. Further examination of the data reveals the corresponding flow rule and scaling law.
Contingent project management-evidence from the field
Contingent project management-evidence from the field

Introduction
Project as a form of organising work is prevalent in todayâ„¢s organisations, most visible in professional services, film production, R&D, construction contractors and IT service providers. As the advantages of organising work in the form of projects being increasingly recognised, more and more organisations project-manage their initiatives to complement their primary operations. As "projects" grow in popularity, so does the need for relevant and rigorously tested theories to guide the management of project-based organisations. The bodies of knowledge that currently dominate the project management profession, such as Project Management Institute's (PMI) Project Management Body of Knowledge (PMBOK), are primarily practice-driven, lack theoretical foundation, and recommend one-size-fits-all approach (Morris 1997; Shenhar 2001; Williams 2004). The poor performance of projects over the past decades also calls for further research into the management of projects. Despite decades of practice and research, projects continue to under-perform (Williams 2004; Johnson 1995; Johnson et al 2001).

More recently, there have been a number of studies examining the typologies for projects (Shenhar 2001; Shenhar Dvir 1996; Evaristo and Fenema 1999; Pich et al 2002). The rationale is that by understanding the typologies, we will be in a better position to design and apply appropriate management approaches. Nevertheless, there has been a lack studies examining the appropriate management approaches in different context, especially at the organisational level. In this presentation, Dr. Liu sums up findings from his research on the issue over the past 8 years. Consistent with the underlying logic of "One-size-does-not-fit-all", the findings shed light on the contingent effects project performance of project management offices, project reviews, project sponsorship and organisational control modes. Theory development, contribution to knowledge and future directions are also discussed.
Bio-mimicry and its application to a Tidal In-Stream Energy Conversion (TISEC) device
Bio-mimicry and its application to a Tidal In-Stream Energy Conversion (TISEC) device

Introduction
Harnessing clean green ocean energy is a key goal in achieving a sustainable future with a diverse renewable energy portfolio. Tidal energy represents a vast untapped resource of ocean energy. But how do we access this resource? Can we look to nature for inspiration?

Through the process of natural selection fish have evolved to posses highly efficient modes of underwater locomotion designed to enable high speeds, efficient long distance swimming and advanced manoeuvrability. Can we apply the characteristics of highly efficient fish swimming modes to develop new, high efficiency tidal stream energy conversion devices? In particular, through adaptive control can we maximise energy extraction of an oscillating bio-mimetic hydrofoil on a hinged lever-am in laminar and turbulent flows.
Compensated Piled Rafts in Clayey Soils: Behaviour, Measurements and Predictions
Compensated Piled Rafts in Clayey Soils: Behaviour, Measurements and Predictions

Introduction
Because of the increasing use of piled raft foundations in buildings with two or more basements, this presentation will show a method of analysis of the behaviour of piled rafts in clayey soils, in which a deep excavation was necessary to achieve the design level of the foundation, here called a compensated piled raft. The soil stresses reduce due to excavation, and the reloading of the soil should be taken into account for this kind of foundation. Many important key factors that are required to achieve a satisfactory comparison of "measurement vs. prediction" are pointed out. All these discussed facts are grouped in a proposed simplified method of analysing compensated piled rafts using numerical tools that can consider the raft-soil-pile interaction. Finally two cases of well-known compensated piled rafts (Hyde Park Barracks in London and the Messeturm in Frankfurt) and a newer building (the Skyper tower-Frankfurt) are analysed using the presented approach. It is discussed how to simulate the structure-foundation interaction.
Could Carbon Trading Benefit the Municipal Solid Waste Management System in Sydney?
Could Carbon Trading Benefit the Municipal Solid Waste Management System in Sydney?

Introduction
Climate change is a driving force behind some recent environmental legislation around the world. Greenhouse emission reduction targets have been set in many industrialised countries. Therefore, a change in current practices of almost all industrial sectors is unavoidable, if the set target is to be achieved. Although waste disposal contributes around 3% of the total greenhouse gas emissions in Australia (mainly due to fugitive methane emissions from landfills), the carbon credit and trading scheme set to start in 2010 presents challenges and opportunities to municipal solid waste practitioners. Technological advances in waste management, if adopted properly, could allow the municipal solid waste sector to act as carbon sink, hence earning tradable carbon credits. However, due to the complexity of the system and its inherent uncertainties, optimizing the system for carbon credits may actually worsen its performance under other criteria. An integrated decision-making system that accounts for uncertainties has been developed in this thesis and is used here to analyse the carbon credit potential of Sydney municipal solid waste.
An introduction to wave energyâ„¢
An introduction to wave energyâ„¢

Introduction
In these times of increased awareness of climate change and growing global energy demand, the necessity for renewable energy technologies development is imperative and ocean power conversion has an important role to play. The International Energy Agency has estimated that wave energy could provide 10% of the worlds electrical energy supply.

This talk will cover the historical evolution of ocean wave energy conversion, review the main technologies that are available today and present the research I have undertaken in this department.
The aim of my research is to study the power capture of a device composed of a hollow vertical cylinder moored to the ocean floor in a manner that allows controlled heaving and pitching. The simple geometry of the device has been chosen as a base model to investigate fundamental system operating parameters, with the view to applying the findings to more complex designs. The cylinder sways with the passing waves, continuously converting the wave energy through the use of a linear generator, with expected power output of around 100 kW.

The tests are carried in the 30m wave tank facility at the School of Civil Engineering, capable of producing complex irregular waves that simulate ocean wave conditions in order to develop a better understanding of behaviour near resonance, develop ways to maximise energy absorption under realistic wave conditions.
Implicit and explicit coupling in transport of salt through liner system
Implicit and explicit coupling in transport of salt through liner system

Introduction
One of the major goals of geoenviromental engineering is to protect groundwater against the presence of man-made chemicals in the natural soil environment. Liners are crucial components of many barrier systems which are used to limit and control contaminant migration from landfill to the groundwater.

Many different types of waste have negative impacts upon the wider environment. Contaminants, which are released to the ground from a landfill, can find their way down into groundwater. Movement of water and dispersion within the aquifer spreads the contaminant over a wider area which makes the water supplies unsafe. In this study the focus will be on barrier systems for municipal soil waste (MSW) with particular emphasis on salt contaminants as an important constituent in waste. The explicit coupling expressed as the influence of hyperfiltration and chemical-osmosis conter-advection on solute transport while implicit coupling expresses the dependence of effective salt diffusion coefficient on the chemical-osmosis efficiency coefficient .

Since the influence of membrane coupling is ignored in the advection-diffusion equation, the objective of the investigation is to assess how the discrepancy between coupled and uncoupled solutions (analysed by Shakelford and Malusis 2004) works when a more realistic representation of the multi-layered liner is used. This implicit and explicit coupling is done using COMSOL multiphysics (Finite Element).
Determination of the base plate stiffness of steel storage racking system and Stiffness tests and load transfer in Drive-in storage racks
Determination of the base plate stiffness of steel storage racking system and Stiffness tests and load transfer in Drive-in storage racks

Introduction
Determination of the base plate stiffness of steel storage racking system

The Fédération Européenne de la Manutention (FEM(1998)) standard proposes a test set-up to determine the rotational stiffness of the base plates of steel storage racks (floor connection). This test set-up is worldly used by rack manufacturers to estimate their rack characteristics. Inconsistence between the figure illustrating the test and associated text can be found, resulting in two different test set up alternatives. Tests performed at the School of Civil Engineering, The University of Sydney investigate both test alternatives. On another aspect, position of the transducers to measure the rotation of the upright section is not explicit. An inappropriate location of the transducers can lead to inaccurate rotational stiffness. This paper clarifies the procedure given in the FEM and produces guidelines to perform base plate tests.

Stiffness tests and load transfer in Drive-in storage racks

Steel storage racks, made of cold-formed steel, are used extensively in industry for storing goods. Two main racking systems prevail, referred to as "selective" and "drive-in" racks. International racking design codes mainly deal with selective racks, while limited design guidelines are available for drive-in racks. Drive-in racks require minimal floor space by storing pallets one after the other with no space between them. The forklift truck drives into the rack to store the pallets on the first-in, last-out principle. To allow forklift passage, drive-in racks can only be braced at the back (spine bracing) and at the top (plan bracing) in the down-aisle direction resulting in a complex slender structure with poorly understood 3D behaviour and increased risk of collapse. As yet, tests on drive-in rack systems to accurately capture the rack 3D behaviour are not available in the literature. This paper presents the preliminary experimental results from full-scale tests conducted on a complete drive-in rack system. Experimental investigations of the load transfer and relative stiffness under various horizontal loading conditions are presented. Experiments have been performed on loaded and unloaded racks.
Rectification of Tilted Structures Using Soil Extraction Technique
Rectification of Tilted Structures Using Soil Extraction Technique

Introduction
Settlement of a foundation usually results from distortion of the underlying soil mass due to shear stresses imposed by the external loads and also due to volume changes which occur as the soil is consolidated. Tilt and distortion are the two common types of foundation failure. Tilt is more dangerous than distortion because distortion shows some visible effects such as cracks, but tilt may cause larger movement without showing noticeable effects. Remedial action is needed for the tilting of towers and buildings when tilts of magnitude 1/100 or greater are measured. There are several techniques available such as jacking, underpinning, grouting, piling, soil removals, etc. for the restoration of a tilted building of which the soil removal method has been proven to be the most effective and permanent solution for settlement problems as it is less costly, requires less fabrication on the structure itself and does not require advanced technology. The soil extraction technique can also be a viable alternative especially for piled raft foundations where other solution methods like jacking are not effective. The main objective of this research is to investigate the efficacy of implementing the soil removal technique to restore a tilted building which will be done by simulating selective excavation of soil, using the finite element method.

When soil layers are removed, the resulting cavities gently close due to the overburden pressure, which then eventually cause a small subsidence of the leaning structure. Analysis for controlled excavation was performed by digging trenches beside a sample raft foundation and its effects on the tilted structure were observed. Similar analysis was done for taking into account the effects of soil removal in the case of piled raft foundation by digging trenches along the full length of some of the piles. Both of these analyses generated satisfactory results for linear and elastic soils.

This research also aims at simulating excavation for Elasto-Plastic soil materials using Mohr-Coulomb and Cam Clay models and also for poro-elastic and non-linear soil