Structures Group seminars

Talk Abstract: Integrated architectural design takes into consideration various parameters at an early stage for the development of optimised buildings. One of these is naturally structural performance. In other words, integrating structural performance in the early conceptual design stages can lead to significant material efficiency as well as aesthetic quality. This presentation will focus on how form-finding frameworks, and in particular graphic statics, can play a crucial role in integrated design and how it can enable the collaboration between architects and engineers. Relevant research conducted at CUED will be showed along with recent examples of applying these methods to projects at Foster + Partners.

Speaker Bio: Marina is an Industrial Fellow of the Royal Academy of Engineering. In her hybrid role spanning industry and academia, she is based at the Specialist Modelling Group (SMG) at Foster + Partners and the Department of Engineering at the University of Cambridge. Marina has a background in applied mathematics and physics, after which she specialised in computational design at the Architectural Association, and civil engineering at the University of Cambridge. She holds a PhD from the Department of Engineering on ‘Geometry-based structural analysis and design’ (graphic statics). Her previous academic and industry collaborations include ETH Zurich (Chair of structural design) and Skidmore, Owings & Merrill (structures group). As a Design Systems Analyst and SMG Research Lead, she specialises in conceptual structural design, form-finding, and architectural geometry. In addition, she contributes to research projects focusing on additive manufacture, robotics, space architecture and extra-terrestrial infrastructure. In her academic capacity, Marina develops computational tools and theoretical frameworks for the design of materially efficient structures using graphic statics.

• Speaker: Dr Marina Konstantatou
• Friday 08 March 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Nishangani Gowrikanthan .

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ABSTRACT :

Concrete may appear as a boring material on a macroscopic level. However, the concrete fracture process exhibits an interesting complex behaviour dominated by disorder, long-range interactions, and long memory in the intensified stress field ahead of the crack tip known as the fracture process zone. The fracture process resulting from such complexity usually generates long-tailed distributions leading to self-organization signifying the emergence of order from the disorder. The existence of self-organization also hints at a universal pattern dominated by simple governing rules, regardless of system configuration. Consequently, entropy can be used as a measure of disorder to quantify the randomness of the probability distributions arising from the system variable. In this study, we propose cumulative distribution functions for acoustic emission features derived from Tsallis’ non-extensive entropy formulation. The Tsallis entropy is well-suited for modeling long-tailed distributions due to its sensitivity to the tail behaviour. Furthermore, the non-linearly interacting multi-scale cracks in the fracture process zone of concrete are inseparable and the whole system cannot be divided into simple sub-systems without tampering with the systemic properties, resulting in non-additivity and non-extensivity.

An experimental investigation was conducted to acquire acoustic emission data from the concrete fracture process. The testing involves three different sizes of notched plain concrete beams under three-point bending subjected to monotonic and fatigue loading. Two features of the AE stress wave, amplitude (magnitude) and inter-event time appear to be correlated with crack size and crack occurrence rate respectively. Distribution functions derived using the Tsallis entropy formulation are then fitted to the experimental data and compared across the beam sizes and loading conditions. The pattern in the collective behavior of entropic indices evaluated from the AE distribution is illustrated to highlight the possibility of self-organization. Monotonic loading controlled by crack mouth opening displacement allows stable crack growth resulting in critical AE distribution parameters that are used as a reference to track the damage evolution under sub-critical fatigue loading.

KEYWORDS : Concrete, Fracture, Fatigue, Acoustic emission, Tsallis Entropy

SPEAKER BIO :

Dr. Nitin Burud is currently working at the University of Surrey as a post-doctoral researcher. He received a doctorate from the Indian Institute of Science, Bangalore, India. His research work focuses on fracture and fatigue in materials, specializing in structural health monitoring applications using statistical data analysis. He worked extensively on acoustic emission techniques for understanding the fracture process in concrete-like cementitious materials. Consequently, his doctoral dissertation is a thematic exploration of acoustic emission data for mechanistic as well as statistical description, diagnosis, and prediction of damage evolution in concrete. Bringing a complexity perspective to understand the fracture process in concrete, and the use of Tsallis entropy as a measure of the complexity, is a central idea of his recent research. Before joining the University of Surrey, he shortly worked as an assistant professor at a deemed university in India. At the University of Surrey, he is investigating the fatigue behavior of a 130-year-old railway bridge through large-scale testing and numerical modeling.

• Speaker: Nitin Burud, University of Surrey
• Friday 15 March 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Sam Cocking.

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ABSTRACT

Strengthening of the built infrastructure is an urgent need in earthquake prone areas. Recent earthquakes worldwide have highlighted the deficiency of existing structures, which may be either damaged from previous strong earthquakes or have been designed without code provisions or designed to old obsolete code provisions. In addition, the majority of the existing structures in low- and middle-income countries have been constructed using substandard materials and without application of anti-seismic code provisions and, therefore, the seismic vulnerability in these areas is of high concern. This seminar is focused on the development of innovative strengthening techniques using novel composite and high-performance materials for the improvement of the structural performance and the durability of existing structural elements. Strengthening of existing Reinforced Concrete (RC) and Unreinforced Masonry (URM) elements has been examined using additional Ultra High-Performance Fibre Reinforced Concrete (UHPFRC) and Fibre Reinforced Geopolymer Concrete (FRGC) elements. Extensive experimental and numerical investigation has been conducted and the effectiveness of the examined techniques in terms of structural performance and durability has been highlighted.

SPEAKER BIO

Dr Andreas Lampropoulos is a Principal Lecturer in Civil Engineering at the University of Brighton. He obtained his Diploma (2003), MSc (2005) and PhD (2010) degrees in Civil Engineering (Structural Division) from the University of Patras in Greece. His main research agenda spans the areas of novel construction materials and seismic strengthening/retrofitting of existing structures. His research interests are focused on a wide range of cementitious materials such as ultra-high-performance fibre-reinforced concrete (UHPFRC), steel fibre-reinforced concrete (SFRC) and cementitious materials reinforced with nanoparticles, and he is also working on the development and application of cement-free concretes. He has conducted extensive experimental and numerical work on the development of novel strengthening techniques for the structural upgrade of reinforced concrete (RC) and unreinforced masonry (URM) structures. Dr Lampropoulos currently serves as the Chair of the International Association for Bridge and Structural Engineering (IABSE) Task Group 1.1 ‘Improving Seismic Resilience of Reinforced Concrete Structures’ and Task Group 5.5 ‘Conservation and Seismic Strengthening/Retrofitting of Existing Unreinforced Masonry Structures’ and he is an active member of various task groups of IABSE and of the International Federation for Structural Concrete (fib). He has had more than 80 works published in international research journals, books and conference proceedings and he is an editorial board member of several international journals in this field. In addition, he is a reviewer for more than 40 international journals, a member of the scientific committee of more than 20 international conferences, and he is an invited reviewer for research proposals for national centres of various countries.

• Speaker: Dr Andreas Lampropoulos
• Friday 01 March 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Nishangani Gowrikanthan .

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Abstract not available

• Speaker: Dr Marina Konstantatou
• Friday 08 March 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Nishangani Gowrikanthan .

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Abstract not available

• Speaker: Nitin Burud, University of Surrey
• Friday 15 March 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Sam Cocking.

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ABSTRACT :

This lecture addresses critical challenges and innovative solutions in the analysis and design of masonry structures, which constitute a significant portion of global architectural heritage. It will showcase work conducted by myself and various research groups I have collaborated with, focusing on developing new analytical and experimental methods for accurately analyzing such structures. Key topics include Membrane Equilibrium Analysis (MEA) and Linear Arch Static Analysis (LASA), both in its analytical and graphical forms. These static methods provide a fundamental understanding of the equilibrium and stress distributions within masonry structures. Furthermore, the presentation will delve into numerical kinematic methods based on block analysis, which offer insights into the dynamic behavior of these constructions under various load conditions. A significant portion of the lecture will be dedicated to laboratory experiments conducted on scaled models of masonry arches. These experiments aim to elucidate the dynamic behavior of masonry structures, providing a solid empirical basis for the theoretical and computational models presented. Additionally, case studies of notable structures that have been designed and assessed using these methods will be discussed. Among these, the Angelus Novus Vault built in occasion of the 2023 Venice Architectural Biennale and the SOM pavilion for COP28 in Dubai will be highlighted, demonstrating the practical implications of the research and the potential for integrating traditional masonry techniques with modern engineering principles to create resilient, efficient, sustainable, and aesthetically pleasing structures.

SPEAKER BIO :

Carlo Olivieri is Assistant Professor of Structural Mechanics at Pegaso University, and was previously Assistant Professor at the University of Salerno. He has collaborated closely with the University of California, Berkeley and Princeton University, and holds an adjunct professorship at the Polytechnical University of Bari. In his Ph.D., he developed Linear Arch Static Analysis, extending classical Thrust Line methods to study curved masonry and concrete spatial structures. His current research focuses on innovative optimization strategies for purely compressive shapes under seismic conditions and the use of low-carbon material blocks for construction. In 2023, he served as structural engineer and site manager for the Angelus Novus vault at the Venice Architectural Biennale, in collaboration with Skidmore, Owings, and Merrill (SOM) and Princeton University.

• Speaker: Carlo Olivieri, Pegaso Università Telematica, Italy
• Friday 23 February 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Sam Cocking.

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The integral bridge typology has become the first choice for road bridges in the U.K. Without any joints between the bridge deck and abutments, maintenance needs are considerably lower than those for a conventional structure with bearings and expansion joints. However, the use of integral bridges is currently restricted to moderate span lengths and skews due to concern for soil settlement and high earth pressures developing in the backfill soil from thermal movements of the bridge deck. The current design code PD 6694 -1 is considered by many to be overly conservative and is thought to mischaracterise the soil-structure interaction behaviour at play. In this talk, the experimental and field work carried out at Cambridge and the University of Pretoria will be presented, giving insight into where current design could be improved.

• Speaker: Douglas Morley
• Friday 16 February 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Callum White.

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The integral bridge typology has become the first choice for road bridges in the U.K. Without any joints between the bridge deck and abutments, maintenance needs are considerably lower than those for a conventional structure with bearings and expansion joints. However, the use of integral bridges is currently restricted to moderate span lengths and skews due to concern for soil settlement and high earth pressures developing in the backfill soil from thermal movements of the bridge deck. The current design code PD 6694 -1 is considered by many to be overly conservative and is thought to mischaracterise the soil-structure interaction behaviour at play. In this talk, the experimental and field work carried out at Cambridge and the University of Pretoria will be presented, giving insight into where current design could be improved.

• Speaker: Douglas Morley
• Friday 16 February 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Callum White.

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Structural engineering spans a wide spectrum of practice, and the work at Cake Industries is very much at the “applied” end, where theory becomes real. Based on several key projects this talk will endeavour to look at how working right at the intersections of design, engineering and making can lead to developments in what is possible.

• Speaker: David Knight, Cake Industries
• Friday 02 February 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Callum White.

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Abstract not available

• Speaker: Neil Thomas, Atelier One
• Friday 26 January 2024, 15:00-16:00
• Venue: CivEng Seminar Room (1-33) (Civil Engineering Building).
• Series: Engineering Department Structures Research Seminars; organiser: Jamie Clarkson.

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