Day 1 :
Keynote Forum
John Campbell
University of Birmingham, UK
Keynote: Entrainment Defects in Steels
Time : 10:00-10:45
Biography:
John Campbell has spent most of his life in the casting industry. He set up the Cosworth Casting Process for Al alloy automotive blocks for racing engines in 1980, which is still the world’s fastest and soundest production technique. From 1989 to 2004, he was Professor of Casting Technology at Birmingham University, UK. He currently works with steel and investment foundries, including Castings Research International, UK. He is the author of a number of books on castings including “Complete Casting Handbook” which is not for the faint hearted, but otherwise recommended for those who want to get their castings right.
Abstract:
The entrainment of the oxide film on the surface of metals during melting and pouring leads necessarily to the incorporation of crack-like defects into the liquid, which are frozen in as crack-like defects in the solid. These are bifilms; doubled-over oxide films, often only a few nanometers thick, across which, between the ceramic oxide-to-ceramic oxide interface, there is no bonding. Although it seems a few steels are naturally free from such cast-in cracks, other constructional steels, including many stainless and bearing steels, are particularly damaged. The current fatigue failures of wind turbine bearings, and cracks in the steels of power plants and helicopter drive shafts are common examples. Ni-based alloys are usually even more susceptible to these defects, greatly affecting the process ability of Ni alloys and their final properties. Simple, low cost improvements to melting and casting process could revolutionize the strength and reliability of steels and Ni alloys, to the point that failure by cracking of an engineering structure would not be possible. It would be a revolution in metallurgy and engineering.
Keynote Forum
Achintya Haldar
University of Arizona, USA
Keynote: Design of Seismic Damage Tolerant Steel Structures
Time : 11:05-11:50
Biography:
Achintya Haldar completed his PhD from University of Illinois. He worked for Bechtel Power Corporation after graduation. After returning to academic career, he worked at Illinois Institute of Technology, Georgia Tech, and now at the University of Arizona. He is a Distingusihed Member of ASCE and a Fellow of SEI. He developed the Stochastic Finite Element Method and many reliabile evaluation concepts applicable to many engineering disciplines. His most recent research is on structural health assessment. He proposed several Kalman filter-based concepts. He received numerous reserach and teaching awards listed at haldar.faculty.arizona.edu. He authored over 575 technical articles including several well accepted books.
Abstract:
Catasprophic failures of structures in some recent seismic events indicate that there is room for improvement. Major weaknesses in current practices are the inability of the profession to incorporate major souces of uncertainty in the formulation, realistic structural behavior leading to failure, and most importantly predicting the exact design earthquake time histrory for a specific site. It is well known that the absolute safety of structures can not be assured but the associated risk needs to be mitigated appropriately. To address excessive economic losses, the performance based seismic design (PBSD) concept is being advocated particularly for steel structures. This risk-based concept is expected to be incorporated in future design guidelines. The speaker and his team proposed several novel conecpts to estimate the underlying risk considering major sources of nonlinearity and uncertainty and applying the seismic loading in time domain. To make design more seismic load tolerant, multiple earthquake time histories need to be considered to incorporate uncertainty in the frequency content. Similar requirements are being introduced in recent design guidelines. After the Northridge earthquake of 1994, to address brittle failures in beam to column connections, several new concepts/features were introduced to design steel structures. Some of these concepts were validated by conducting experiments. The methods proposed by the speaker’s team can quantify significant reduction of risk in the presence of these features. Several related topics to make steel structures more sesimic damage tolerant will be presented.
Keynote Forum
Murude Celikag
Eastern Mediterranean University, North Cyprus
Keynote: Moment-Rotation Characteristics Of Reverse Channel Connections To Tubular Columns
Time : 11:50-12:35
Biography:
Dr. Celikag has completed her PhD in 1990 from University of Sheffield, UK. She then worked with reputable international companies in UK, Singapore and UAE. In 1994 she became Chartered Engineer in UK (MICE). She worked as an Adjunct Professor at UAE University before she joined Eastern Mediterranean University (EMU) in 2000. Besides she is the director of ROBUST Engineering and Consultancy Ltd, at EMU Techno Park. She has been the author of around 35 research articles/book chapters and supervised more than 40 postgraduate students. She is serving as reviewer to reputed ISI journals.
Abstract:
The effect of material properties and the geometrical configurations of reverse channel flush end-plate connections (RCC) on the moment-rotation (M-ï¦) relationship under monotonic loading are presented in this paper. The main focus of this research was on the stiffness, strength, sources of deformability, rotational capacity and failure mechanisms of the RCC. The investigations were based on parametric studies performed by using general finite element package ABAQUS (v.6.12) software. Hence, three-dimensional (3-D) FE models were developed for 268 specimens. The developed models were validated against the experimental results available from literature. All tests were able to achieve a rotational capacity beyond the minimum 0.03 rad. The results of the parametric study indicate that the key to the rotational capacity of RCC was found as the channel wall thickness to the flush end-plate thickness ratio. Furthermore, the ratio of channel depth to square hollow section (SHS) width was mainly responsible for the deformability of the column face and 0.72 is recommended as the minimum value of this ratio. On the other hand, the use of HSS (S690) reverse channel as part of the joint; compared to mild steel (S355), produced remarkable increase in both ultimate flexural resistance and the rotational capacity without compromise to the initial stiffness.
Keynote Forum
Jose Turmo
Universitat Politècnica de Catalunya, Spain
Keynote: Structural Sytem Identification Of Steel Structures
Time : 12:35-13:20
Biography:
Jose TURMO (Spain, 1974) got his 6-year program degree in Civil Engineer (1998) from University of Cantabria (Santander, Spain) and his PhD (2003) in Construction Engineering from Technical University of Catalonia BarcelonaTech- UPC (Barcelona, Spain). At the moment, he is Professor in the School of Civil Engineering in Barcelona, BarcelonaTech (Spain), where he teaches Construction Engineering. His area of expertise is Bridge Engineering and Structures.
Abstract:
The need for structural system identification, model updating and health monitoring is constantly growing as the structural stock of modern societies is getting considerably bigger. In order to ensure that an already built construction is structurally sound, data can be gathered from nondestructive dynamic or static tests or dynamic behavior can be recorded from ambient vibration. Whereas the methods to study dynamic data have been thoroughly studied and developed, much less attention has been paid to the study of nondestructive static tests. A new parametric method for structural system identification which is based in a mathematical technique called observability will be presented. It is said that a subset of variables is observable when the system of equations implies a unique solution for this subset, even though the remaining variables remain undetermined. This leads to the observability problem that has a relevant role in many engineering problems, among them the structural system identification. The application of observability will lead to identify which are the relevant measurement sets to be used in order to identify a given set of targeted structural parameters. The applications of such method to identify structural unknowns, such as bending of axial stiffness’s, from measured deflections or rotations, will be outlined. The impact of measurement errors on the accuracy of the solution will be highlighted as well as different techniques to improve the results of the estimates for steel bridges and building frames.
- Plenary Session
Location:
Session Introduction
Ernst Gamsjager
Montanuniversitat Leoben, Austria
Title: Microstructural changes in steels – recent advances in experiments and modelling
Time : 14:05-14:35
Biography:
Ernst Gamsjager has completed his PhD in 2002 and worked as a Post Doc with Prof. Militzer at the University of British Columbia, Canada and Prof. Fratzl, Max Planck Institute of Biomaterials, Germany. He obtained the Masing Memorial Award of the German Society of Materials Science in 2007. Since 2010 he works as an associate professor at Montanuniversitat Leoben, Austria. He has published more than 45 papers in reputed journals and is very active in reviewing manuscripts. He is member of the management committee of the Cost action CA15102 “Solutions for critical raw materials under extreme conditions”.
Abstract:
The microstructures of steels evolve during processing and determine the properties of these materials, which is a strong motivation to investigate the kinetics of phase transformations, recrystallization and subsequent grain growth both experimentally and by modelling. Models based on the relevant physical principles are a precondition to improve the understanding of microstructure-property relationships. Based on in-situ experiments the evolving microstructures can be subjected to a controlled thermo-mechanical treatment. The experimental results will be interpreted by means of thermodynamically based modelling in order to gain new insights about the underlying physics when designing new materials. Microstructural changes during thermal processing are analysed in detail. It is demonstrated that variables describing the microstructural evolution are directly correlated with mechanical properties such as ultimate tensile strength and impact strength.
Nong-Moon Hwang
Seoul National University, South Korea
Title: Abnormal grain growth in Fe-3%Si steel
Time : 14:35-15:05
Biography:
Nong-Moon Hwang has completed his PhD in Material Science and Engineering, Korea Advanced Institute of Science and Technology in 1986. He is a Professor in the Department of Material Science and Engineering, Seoul National University (SNU). From 1986, he worked in Korea Research Institute of Standards and Science until he joined the faculty in SNU in 2003. He has published more than 200 SCI papers and a former Director of Research Institute of Advanced Materials and a former Vice President of Korea Institue of Metals and Materials.
Abstract:
Abnormal grain growth (AGG), which is also called the secondary recrystallization, often takes place after primary recrystallization of deformed polycrystalline materials. A famous example is the evolution of the Goss texture after secondary recrystallization of Fe-3%Si steel. A selective AGG of Goss grains has remained a puzzle over 70 years in the metallurgy community since its first discovery by Goss in 1935. In an ambitious attempt to solve this puzzle, we suggested the sub-boundary enhanced solid-state wetting as a mechanism of selective AGG of Goss grains. According to this mechanism, if Goss grains have sub-boundaries of low energy, they have an exclusively high probability to grow by solid-state wetting compared with other grains without sub-boundaries. The existence of sub-boundaries in Goss grains was experimentally confirmed not only in our group but also in other groups. In order to understand why only Goss grains have sub-boundaries, the cold rolling process of the hot-rolled Fe-3%Si steel was analyzed by finite element method (FEM). The analysis showed that a small portion of Goss grains formed during hot rolling survives after cold rolling; the survived Goss grains have the lowest stored energy and are expected to undergo only recovery without recrystallization, producing sub-boundaries.
Giovanni Totaro
CIRA-Italian Aerospace Research Center, Italy
Title: Anisogrid lattice structures: an interesting paradigm for civil engineering
Time : 15:05-15:35
Biography:
Giovanni Totaro has graduated cum laude in Mechanical Engineering at Federico II University of Naples. He has pursued his PhD in Aerospace Engineering from TU Delft University of Technology in 2011. He is Researcher in the field of Advanced Composite Materials at CIRA. He has published several papers in reputed journals including Design Methods of Composite Lattice Structures.
Abstract:
Anisogrids, that is, non-isotropic grids, represent a specific design concept in composite material conceived to maximize the efficiency of cylindrical and conical lattice shell structures subjected to high compressive and bending loads that are usually encountered in aerospace applications. This concept consists of a regular, dense and symmetric system of the continuous interlaced unidirectional hoop and helical ribs forming a pattern of triangular and hexagonal cells. Helical ribs are normally coincident with the geodesic trajectories of the shell. These structures can be supplemented with a thin outer skin, which normally increases the critical global buckling load, or provides only an external coverage. Automated winding deposition is the basic technology. Anisogrids represent an excellent paradigm for the development of lightweight primary structures, not necessarily limited to composites. In conjunction with composites, they have clearly expressed the maximum potentiality in the field of space launcher vehicles - where the weight efficiency is of primary importance - as demonstrated by the serial production of inter stages and cone adapters referred to the Russian space launcher Proton-M. In fact, replacing the aluminum structures based on the conventional skin-stringer architecture with optimized anisogrids may result in a considerable weight saving around 40%. Actually, the first real precursor of the modern Anisogrids is just related to a civil application, namely, the Moscow radio tower dated 1921. Other than aerospace field, existing and possible application of lattice structures include: masts, columns, pipes, and other elements of civil engineering structures.
- Speaker Session
Chair
John Campbell
University of Birmingham, UK
Session Introduction
Massood Mofid
Sharif University of Technology, Iran
Title: Double web angle connection behaviour and rigidity in existence of gusset plate
Time : 15:35-16:05
Biography:
Massood Mofid has received his PhD in 1989 from Rice University, Houston Texas. He is a Professor of Earthquake and Structural Engineering in the Department of Civil Engineering at Sharif University of Technology, Tehran, Iran.
Abstract:
Typically, beam to column connections in braced frames are assumed and designed as a simple connection. One of the most common beam to column connections in these frames is double web angle connection. In research and design procedures of structures that have been done so far, this type of connection is generally considered as a simple hinged connection. In beam to column joints there are bracing(s) and therefore gusset plate(s) at bottom and/or top of the beam, the gusset plate restrains the beam from rotation at its connection to the column. Therefore, double web angle connection is not allowed to have relative rotation between the beam and column and it does not have the adequate rotation capacity to accommodate desired free rotation assumed in structural analysis. There have been just a few researches on the effect of stiffness of gusset plate on mentioned connection up to now. The most studies in this regard, are related to the investigation of braced frame and gusset plate and in this paper, the behavior of double web angle connection is investigated using the FEM method considering stiffness of gusset plate and using the moment-rotation curve of connection; and it is showed that the assumption of hinge connection in beam to column connections in mentioned locations is not correct. Therefore, another assumption should be taken in modelling of structures. Furthermore, the response of structure frames is investigated considering stiffness of connection.
Sudhir P Patil
Maharashtra Institute of Technology, India
Title: Parametric study of steel fiber reinforced concrete members subjected to shear, bending and torsion
Time : 16:20-16:50
Biography:
Sudhir P Patil has completed his PhD from Mumbai University, India. He is an Associate Professor in the Department of Applied Mechanics, Maharashtra Institute of Technology, Pune, Maharashtra. He has published more than 20 papers in reputed journals.
Abstract:
An attempt is made in this experimental study, the effects of the fly ash and steel fibers on compressive, split tensile, shear, flexural, and torsional strength of high strength plain and steel fiber reinforced concrete beam specimens. In this program, 99 cubes and 18-cylinder samples are cast for a trial mix design. The trial mixes are with different percentages of fly ash and steel fibers. The concrete mixes have 10%, 20%, and 30% of fly ash by replacing cement to its weight and 0%, 0.5%, 1%, 1.5%, 2.0% and 2.5% of steel fibers by the weight of cement concrete. The compressive strength of the steel fiber reinforced concrete (SFRC) reaches the maximum at 20% fly ash and 1.5% volume fractions of steel fiber. The splitting tensile strength and the modulus of rupture improve with an increasing volume fraction. To study flexural strength behavior, a total number of 60 beam specimens of size 150 x 150 x 1500 mm are cast. 12 beam specimens without pre-stressed and 24 beam specimens with pre-stressed by adding 20% fly ash and 1.5% steel fiber and 12 beam specimens without and 12 beam specimens with pre-stressed casting with plain concrete by adding 20% fly ash. A primary finding emerging from the experimental program is that the placement of steel fibers increased the load carrying capacity of SFRC beam specimen. Also, it enhanced ductility, modulus of elasticity (Ec), shear modulus (G), Poisson’s ratio (μ), torsional stiffness of concrete (Kt), energy absorption, shear, flexural, and torsional shear strength.
- Young Research Forum
Chair
John Campbell
University of Birmingham, UK
Session Introduction
Badriya Almutairi
Loughborough University, England (UK)
Title: CO2 Emissions from Wind Turbine in Kuwait
Time : 16:50-17:10
Biography:
Badriya Almutairi is a PhD student at the school of architecture, building and civil engineering, at Loughborough University. She received a B.S. degree and then M.S. in civil engineering from the College of Engineering and Petroleum at Kuwait University. She has been a structural engineer at the Public Authority for Housing Welfare in Kuwait for over 10 years. Her current research is in the area of renewable energy, soil-structure interaction, and finite element modeling, with an emphasis on wind energy systems.
Abstract:
The source of renewable energy of wind energy in the Middle East and particularly in GCC countries showing some recommendation as the feasibility of wind energy technology use in Kuwait. The aim of this paper is to review the life cycle assessment in Kuwait and its four stages including goal and scope of the analysis, inventory analysis, impact assessment and interpretation of results. This study shows the inventory of carbon and energy data of the material that assemble Gamesa 90-2MW as well as CO2 emissions for different type of transportation, it also calculate a number of relevant parameters related to the energy consumption, such as CO2 emissions and energy payback time of wind turbine. These results are compared with other sources of energy based on fossil fuels to assess the potential of wind plants; due to lack of information data from Brazil which is similar to Kuwait environmental conditions has been used. The results showed that CO2-eq per generated power are different according to the difference in turbine model and also showed total carbon dioxide for turbine with steel pile foundation is greater than emission from turbine with concrete foundation of about 18 percent. It revealed that the total annual energy generated for both turbines is the same because they have the same Gamesa 90-2MW wind turbine is used.