Andreas Taras: Catalogue data in Autumn Semester 2022
|Prof. Dr. Andreas Taras
|Steel and Composite Structures
Professur Stahl- und Verbundbau
ETH Zürich, HIL D 36.1
|+41 44 633 45 52
|Civil, Environmental and Geomatic Engineering
|Project Work Conceptual Design
|A. Taras, F. Ortiz Quintana
|A structure to be designed serves as a mean to practice the holistic approach of conceptual design by working in parallel and iteratively on different levels of detailing. Both, requirements and scope of action, are identified by the students and serve as basis for a solution. The task group organizes itself to solve complex tasks.
|The project work conceptual design conveys a first insight into the holistic approach to cope with typical tasks of civil engineering and introduces professional techniques of civil engineering to students.
A further aim is to consolidate the knowledge gained so far in bachelor courses, to link different domains and to fill gaps with respect to work techniques. The students analyse the inventory, formulate design requirements and boundary conditions, elaborate approaches and proposals for solutions, dimension some exemplary structural elements, practise detailing and document their work by different media.
Analysis of the inventory, layout of posters, basics of graphic representation, service criteria agreement and basis of design, structural design and modelling, preliminary dimensioning, technical drawing and model making, materialisation and detailing, literature research and scientific referencing.
Excursion with mission, lectures, autonomous work, poster session, role playing, workshop, exemplary plenary review.
Poster, sketches, service criteria agreement and basis of design, static calculations, plans, models.
|Codes SIA 260, 261, 400
|Fatigue and Fracture in Materials and Structures
Does not take place this semester.
|The fundamentals in fatigue and fracture mechanics, which are used in different engineering disciplines (e.g., for mechanical, aerospace, civil and material engineers) will be discussed. The focus will be on fundamental theories (based on fracture mechanics) that model fatigue damage and crack propagation.
|In this course, the students will learn:
• Mechanisms of fatigue crack initiations in materials.
• Linear elastic and elastic-plastic fracture mechanics.
• Modern computer-based techniques (using ABAQUS Finite Element Package) to simulate cracks in both bulk materials and bonded joints/interfaces.
• Laboratory fatigue and fracture tests on details with cracks.
|The course starts with a discussion on the importance of fatigue and fracture in different engineering disciplines such as mechanical, aerospace, civil and material engineering domains. The preliminary topics that are covered in this course are:
I) Fatigue of materials:
• Mechanisms of fatigue crack initiation in (ductile and brittle) metals.
• Crack initiation under uni-axial high-cycle fatigue (HCF) loadings: Wöhler (S-N) curves, constant life diagram approach (mean-stress effects), rainflow analysis and Miner's damage rule.
• Crack initiation under multi-axial HCF loadings: multi-axial fatigue mechanisms, critical plane approach (critical distance theory), equivalent stress approach, proportional and non-proportional loading.
II) Fracture mechanics:
• ELinear elastic fracture mechanics (LEFM): limits of LEFM, stress intensity factors, crack opening displacement, mixed-mode fracture, etc.
• Elastic-plastic fracture mechanics: Irwin and Dugdale models, plastic zone shapes, crack-tip opening displacement and J-integral.
• Fatigue crack growth (FCG): FCG models, Paris' law, cyclic plastic zones, crack closure effects. This also includes FE modeling of the FCG and laboratory tests (at Empa).
III) Introduction to cohesive zone models (CZMs):
• Advantages and disadvantages of CZMs compared to fracture mechanics.
• Different bond-slip models for the bonded joints/interfaces.
IV) Computer laboratory to simulate cracks and debonding problems:
• Finite Element (FE) modeling of complex details with cracks.
• FE simulations of debonding problems using CZMs.
• Computer laboratory: FE training and exercises using (the student edition of) the ABAQUS FE Package.
V) Introduction to fatigue and fracture design in civil structures. Different methods for fatigue strengthening will be disscussed.
VI) Visits to the Empa (Swiss Federal Laboratories for Materials Science and Technology) in Dübendorf, and “Laboratory Competition”. The students will:
• Visit different small-scale and large-scale fatigue testing equipment.
• Get to know different ongoing fatigue- and fracture-related projects.
• Witness and help to conduct a fatigue test on a steel plate with a pre-crack and a fracture test on an adhesively-bonded joint.
• Compare the experimental results with their own calculations (from the fracture theories).
• “Laboratory Competition” at Empa: the students with the closest predictions will win the “Empa Laboratory Competition” and will be awarded by a prize.
|Lectures are based on the lecture slides and the handouts, which will be given to the students during the semester.
|1. Schijve J. “Fatigue of Structures and Materials”, 2008: New York: Springer.
2. Anderson T.L. “Fracture Mechanics - Fundamentals and Applications”, 3rd Edition, Taylor & Francis Group, LLC. 2005.
3. Budynas R.G., Nisbett J.K. “Shigley's Mechanical Engineering Design”, 2008, New York: McGraw-Hill.
|Prerequisites / Notice
|Note 1: A basic knowledge on mechanics of structures and structural analysis (i.e., stress-strain analysis and calculations of internal deformations, strains and stresses within structures) is recommended and will be helpful in the course.
Note 2: Laboratory demonstrations and fatigue/fracture tests at the Structural Engineering Research Laboratory of Empa in Dübendorf. This includes laboratory tours and showcasing the Empa large-scale 7-MN fatigue testing machine for bridge cables, different fatigue and fracture testing equipment for structural components, etc.
|Steel Structures II
|Theoretical foundation and constructional features of the design and construction of steel and steel-concrete composite structures. Multi-storey buildings and bridges. Structural analysis for steel-concrete composite structures. Plate buckling of unstiffened and stiffened panels. Fatigue resistance and safe life assessment. Detailling, drafting, fabrication and erection, cost estimation.
|Students will expand the knowledge acquired during "Steel Structures I" and learn how to apply these skills to the design of more complex building and bridge steel and composite structures. They will acquire the fundamental background for the phenomena of plate buckling and fatigue and learn how to apply it to practical design tasks. In addition, students will learn to appreciate the importance of questions of detailling, fabrication, erection and cost calculation for the effective design of steel and composite structures.
After completion of the year-long course in Steel Structures I+II, students will have at their disposal a wide and detailled set of skills concerning the modern practice for steel and composite structures design and have a deep understanding of its theoretical & scientific background. The examples of scientific and standardisation work provided in the lectures give the students the opportunity to learn about the most current developments and see how these are used to shape the future practice in the structural engineering field.
|The lecture Steel Structures II complements the knowledge acquired in part I by providing students with additional theoretical and practical knowledge, e.g. on the design of steel and composite structures against fatigue, plate buckling, as well as on the structural modelling and analysis of more complex building and bridge structures. These more theoretical topics will be exemplified and illustrated by applications to real problems in the design of bridges and multi-storey building structures. Finally, the course will provide detailled insight into aspects pertaining to structural detailling, fabrication, erection and cost estimation for constructional steelwork.
- Structural forms, analysis techniques and modelling of multi-storey buildings and bridges.
- Structural analysis (deformations, internal forces, stresses and strains) in steel-concrete composite girders considering the effects of creep, shrinkage and shear deformations.
- Elastic and plastic longitudinal shear transfer mechanisms and effects
- Plate buckling of unstiffened and stiffened panels
- Fatigue resistance and safe life assessment: phenomenon and design approaches
- Special topics of steel connection design
- Detailling, drafting, fabrication and erection, cost determination in constructional steelwork
|Lecture notes and slides. Worked Examples with summary of theory. Design aids and formula collections. Videos of lectures.
|- J.-P. Lebet, M. Hirt: Steel Bridges, Conceptual and Structural Design of Steel and Steel-Concrete Composite Bridges, EPFL Press
- Stahlbaukalender (various editions), Ernst & Sohn, Berlin
|Prerequisites / Notice
|The content of steel structures I is a prerequisite
|Steel Structures III: Advanced Steel and Composite Structures
|A. Taras, U. Angst
|Expand the theoretical background and practical knowledge in the design of steel and composite structures. Special composite construction and detailling: partial connection, serviceability. Fire design. Cold-formed steel design. Crane girders; masts; tanks & silos. Structural glazing and lightweight cable-supported structures.
|In Steel Structures III, students will deepen and expand their theoretical background and practical knowledge of the design and construction of steel and composite structures. The focus of the course lies on design tasks and solutions in modern, multi-storey, steel-framed buildings driven by architectural needs, as well as on certain special fields of application of steel structures. Students will learn how to solve complex structural engineering tasks in larger building projects, e.g. through the use and correct design of large-span slim-floor girders and ultra-slender composite columns, or the use of glazing and cable structures as principal load-carrying components. They learn how steel structures behave under fire conditions and how they can be protected and designed accordingly. Finally, students learn about the fundamental aspects governing the design of specialty steel structures, such as thin-walled cold-formed sections, crane girders, masts and storage tanks.
The examples of scientific and standardisation work provided in the lectures give the students the opportunity to learn about the most current developments and see how these are used to shape the future practice in the structural engineering field.
|Steel Structures III provides in-depth theoretical background and practical knowledge on advanced design topics in steel and composite structures. The focus of the course lies on design tasks and solutions in modern, multi-storey, steel-framed buildings driven by architectural needs, as well as on certain special fields of application of steel structures. The course discusses the use and design of large-span slim-floor girders and ultra-slender composite columns, as well as the use of glazing and cable structures as principal load-carrying components. The design of steel structures under elevated temperatures (fire conditions) is treated, as well as special topics of design for serviceability. In addition, fundamental concepts of the design of cold-formed steel framed structures are discussed. Finally, the course will give an overview on the design of specialty steel structures, such as crane girders, masts and storage tanks.
|Slides and lecture notes. Worked examples. Handouts and formula collections.
|Stahlbaukalender (various editions), Ernst + Sohn, Berlin
|Prerequisites / Notice
|Prerequisites: Steel Structures I and II
|Colloquium in Structural Engineering
|A. Taras, E. Chatzi, A. Frangi, W. Kaufmann, B. Stojadinovic, B. Sudret, M. Vassiliou
|Professors from national and international universities, technical experts from the industry as well as research associates of the institute of structural engineering (IBK) are invited to present recent research results and specific projects from the practice. This colloquium is adressed to members of universities, practicing engineers and interested persons in general.
|Learn about recent research results in structural engineering.