Faculty of Engineering 2

Doctor of Philosophy

ABEYSIRIWARDENA, Kodikara Arachchillage Tharindu Malinga

Thesis Title

Cold-Formed Steel Stud Walls Subject to Distortional Buckling Failures Under Ambient and Fire Conditions

Supervisors

• Dr Anthony Deloge Ariyanayagam  (Associate Supervisor)
• Professor Mahadeva Mahendran  (Principal Supervisor)

Citation

Structurally efficient cold-formed web-stiffened steel studs are increasingly used in light steel framed walls, but they are prone to distortional buckling. This research investigates the distortional buckling behaviour of gypsum plasterboard sheathed studs under both ambient and fire conditions. Using experimental, numerical and analytical studies, the composite behaviour of steel studs and sheathing subject to distortional buckling was investigated and improved design guidelines were developed allowing for safe and economical design. Overall, this research has significantly enhanced the knowledge and understanding of the behaviour and design of cold-formed steel stud walls subject to distortional buckling under ambient and fire conditions.

BADATHURUGE, Chamari Pamoshika Jayarathna

Thesis Title

Transforming Logistics Systems Towards Sustainability and Circular Economy

Supervisors

• Adjunct Professor Duzgun Agdas  (Associate Supervisor)
• Professor Leslie Anthony Dawes  (Principal Supervisor)

Citation

This thesis explores the pathway towards sustainability and circular economy in logistics systems. The research identifies widely used sustainability indicators, how logistics sector incorporates sustainability practices toward circular economy, explores the relationship between green logistics practices and sustainability performance, and proposes a model to assess green logistics practices towards a circular economy. The findings contribute to the logistics industry to develop a standard for reporting sustainability, enabling performance comparison, and supporting strategy implementation towards a circular economy. Regulatory bodies can use the findings to formulate policies on sustainability and circular economy at the micro, meso, and macro levels.

BASHIR, Nadia

Thesis Title

Assessing the Impact of Disasters on Transport Networks

Supervisors

• Professor Leslie Anthony Dawes  (Associate Supervisor)
• Dr Marc Philipp Miska  (Principal Supervisor)

Citation

Floods of Brisbane have compelled researchers to investigate ways to assess the impacts of these floods on the road networks and to design solutions that will help the decision-makers in prioritising investments on roads that are critical for connectivity and operability of the networks before, during and after the disasters. This research, therefore, serves two primary goals. Firstly, it identifies the vulnerable communities within Brisbane, and secondly, it proposes an add-on decision-making tool for Benefit-Cost Analysis of critical transport infrastructure - which considers community focussed parameters of robustness, accessibility and operability of the road network.

BRANNI, Marco Giuseppe

Thesis Title

Constitutive Models of Bone: The Human Femur

Supervisors

• Saulo Martelli  (Principal Supervisor)
• Mr Egon Perilli  (External Supervisor)
• Professor Peter Pivonka  (Mentoring Supervisor)

Citation

Bone is a lightweight structure that adapts in time to support habitual loads through a dense cortical shell and an intricate trabecular network to best support daily loads while minimizing weight. The present project aimed at understanding the contribution to support of cortical and trabecular bone structures using high-resolution images of human femurs, microstructural finite-element modelling and bone loads caused by physical activity. This information can be used to advance methods for the early diagnosis of patients most at risk for fracture, to develop targeted exercise interventions for bone health and to optimize the design of orthopaedic devices.

GOLBABAEI, Fahimeh

Thesis Title

Challenges and Opportunities in the Adoption of Autonomous Demand Responsive Transit (ADRT) by Adult Residents of South East Queensland

Supervisors

• Associate Professor Jonathan Michael Bunker  (Principal Supervisor)
• Dr Jinwoo Lee  (External Supervisor)
• Professor Alexander Paz  (Associate Supervisor)
• Professor Tan Yigitcanlar  (Associate Supervisor)

Citation

This project examined how the South East Queensland adult residents' demographic profiles influence their current mobility behaviour, perceptions, and adoption of autonomous shuttle buses. The method includes an online stated preference survey distributed across urban and peri-urban areas, complemented by a wide-ranging review of prior global studies, descriptive and ordinal/binary logistic regression analysis, and partial least structural equation modelling. The findings were validated through qualitative study by interviewing transport experts. The research findings provide comprehensive insights to assist policymakers, transport planners and engineers in their policy decisions and system plans contributing to the wider uptake of ADRT technology solutions.

MATARAMBA KANKANAMGE, Kasun Dilhara Wimalasena

Thesis Title

Evaluate the Performance of Geosynthetic Reinforced Subgrades Under Monotonic Loading

Supervisors

• Associate Professor Chaminda Gallage  (Principal Supervisor)
• Dr Yilin Gui  (Associate Supervisor)

Citation

A series of large-scale pavement model tests were conducted in a laboratory environment to investigate the effect of geosynthetics in improving the modulus of weak subgrades. Then, a series of supplement design charts that could be useful for industry practitioners to design geosynthetic reinforced flexible pavements were developed. The outcomes of this study promote the use of geosynthetics in road construction to make economical, environmentally friendly, climate resilient, and sustainable road infrastructure.

MILLER, Corey James

Thesis Title

Mechanostat Regulation of Cortical Bone Adaptation due to PTH and Mechanical Loading: Insights from Image Analysis and In Silico Modelling of the Mouse Tibia

Supervisors

• Dr Enrico Dall'Ara  (External Supervisor)
• Professor YuanTong Gu  (Associate Supervisor)
• Dr Edmund Ian Marcus Pickering  (Associate Supervisor)
• Professor Peter Pivonka  (Principal Supervisor)

Citation

Osteoporosis is a significant worldwide health concern. Studies in mice have revealed that two treatments, parathyroid hormone (PTH) and exercise, show enhanced anabolic benefits of bone adaptation. However, the localised adaptation response is not well understood, and current computational models lack sufficient integration of the two treatments. This thesis aimed to create a hybrid mechanobiological simulation platform capable of predicting bone adaptation to the two treatments, guided by additional investigations of localised adaptation in mouse tibia studies. Such a model enables rapid exploration of treatment combinations, thereby guiding future experiments towards the development of patient-specific treatment plans for osteoporosis.

PAUL, Sattwikesh

Thesis Title

Gelatin-Methacryloyl-Chitosan (GelMA-CS) Hydrogel: a Novel Orthopaedic Bioadhesive

Supervisors

• Professor Travis Klein  (Principal Supervisor)
• Dr Karsten Schrobback  (Associate Supervisor)

Citation

Cartilage has limited self-repair ability and often degenerates after injury if left untreated. This thesis presents the development of a novel photo-cross-linkable GelMA-glycol chitosan hydrogel for use as a bioadhesive in cartilage repair. The hydrogel is injectable, biocompatible, mechanically robust, and highly adhesive to cartilage. Ex vivo joint studies confirmed its secure attachment to cartilage, even under minimal load-bearing conditions. Moreover, its adhesive strength improved over time, even during dynamic mechanical loading resembling joint movement. This thesis demonstrates the promising potential of this bioadhesive hydrogel for cartilage repair and regeneration, encouraging further research in this area.

PIEPER, Lisa

Thesis Title

Cold-Formed Steel Cladding Systems Exposed to Combined Wind and Bushfire Conditions

Supervisors

• Dr Anthony Deloge Ariyanayagam  (Associate Supervisor)
• Professor Mahadeva Mahendran  (Principal Supervisor)

Citation

Bushfire events have shown a strong interaction between the bushfire front and ambient winds leading to fire-enhanced wind action, which may cause premature damage to the steel cladding systems used as the critical external building envelope. Therefore, this thesis investigated the behaviour and strength of crest-fixed cold-formed steel (CFS) claddings under combined wind and bushfire actions. Comprehensive experimental and numerical studies of three CFS cladding systems were conducted under combined fire-enhanced wind action and elevated temperatures, and new design rules were developed. This research has thus enhanced the safety of CFS claddings in bushfires and overall bushfire resilience of buildings.

RAJAPAKSHAGE, Ruwanika Chandramani Piyasena

Thesis Title

Blast Response of Cable Supported Glass Facades

Supervisors

• Professor Hung Tin Tommy Chan  (Associate Supervisor)
• Adjunct Professor Nimal Jayantha Perera  (Associate Supervisor)
• Professor David Pathmaseelan Thambiratnam  (Principal Supervisor)

Citation

This research developed techniques to determine the response of cable supported glass facades to credible blast events and evaluated the effects of controlling parameters. Research outcomes will enable to provide mitigation strategies to vulnerable buildings fronted by such glass facades.

REIS, Sonia Elizabeth

Thesis Title

Career Optimism of Civil Engineers in Australia

Supervisors

• Associate Professor Jonathan Michael Bunker  (Principal Supervisor)
• Professor Leslie Anthony Dawes  (Associate Supervisor)

Citation

Projects of local, national and global significance are being impacted by the shortage of civil engineers. This engineering skills shortage is predicted to negatively affect many nations' ability to develop economic strength and to build and maintain their infrastructure safety. This research has investigated and modelled the factors impacting the career optimism of civil engineers in Australia, providing insights and leadership strategies to improve their satisfaction, tenure and productivity. Engineering employers, managers and professional associations can use these practical management strategies to lead a diverse and multigenerational engineering workforce improving civil engineers' career optimism.

SPARKS, David Steven

Thesis Title

Convergence of Scaffold-Guided Bone Regeneration Principles and Reconstructive Surgery: A Regenerative Matching Axial Vascularisation Approach to the Load-Bearing Long Bone Defect

Supervisors

• Distinguished Professor Dietmar Hutmacher  (Principal Supervisor)
• Dr Siamak Saifzadeh  (Associate Supervisor)
• Professor Michael Andreas Schuetz  (Associate Supervisor)
• Dr Michael Wagels  (External Supervisor)

Citation

Functional reconstruction of large volume bone loss in the limbs is demanding. Reconstructive approaches available have variable success and novel approaches, such as those incorporating tissue engineering methods, are required. The thesis describes and evaluates the rare bench-to-bedside translation of a novel tissue engineering technique, termed Regenerative Matching Axial Vascularisation (RMAV), to reconstruct major bone loss in the load-bearing limb where contemporary surgical options are limited. The work described takes the marriage between scaffold-guided tissue regeneration and modern surgical practice to new heights.

THAKKAR, Smit Bharat

Thesis Title

A Novel Framework for Time Series Clustering Based on Distribution and Geometric Distance

Supervisors

• Professor Ashish Bhaskar  (Principal Supervisor)
• Professor Alexander Paz  (Associate Supervisor)

Citation

Recognizing patterns in transport data is crucial for planning and traffic management. This research proposes a framework for clustering transport time series data by modeling objects as probability distributions. It introduces a robust distance measure, utilizes Kernel Density Estimation for distribution distances, incorporates a composite measure for temporal trends, and offers intuitive cluster evaluation. Applied to travel time data from Finucane Road in Brisbane, it demonstrates effectiveness and broader applicability. By explicitly considering probability distributions, this framework addresses limitations of traditional divergence measures. It provides a systematic approach for handling large transport-related data, facilitating informed decision-making in various transport applications.

THATTASSERRY JOSEPH, Jomon

Thesis Title

Structural Damage Identification Under Mass Variation Using Modal Kinetic Energy

Supervisors

• Professor Hung Tin Tommy Chan  (Principal Supervisor)
• Dr Khac Duy Nguyen  (Associate Supervisor)

Citation

Civil structures are susceptible to deterioration due to environmental and man-made factors. Early intervention is essential to keep them in healthy condition. Early intervention is possible only if damage information, especially the extent of damage can be identified promptly and accurately. Researchers have developed various damage identification methods in recent decades, but practical challenges have discouraged their application to real structures. One of these challenges is the influence of mass changes at two different states on modal measurements. This thesis reports the successful development of Modal Kinetic Energy (MKE)-based damage identification methods for structures subjected to stiffness and mass changes.