Dynamic Behaviour of Concrete Structures subjected to Blast and Fragment Impacts
Author: JOOSEF LEPPÄNEN | Size: 1.8 MB | Format:PDF | Quality:Unspecified | Publisher: Department of Structural Engineering Concrete Structures CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 2002 | Year: 2002
For protective structures, reinforced concrete is commonly used. Concrete structures
subjected to explosive loading in a combination of blast and fragments will have very
different response than statically loaded structure. During the blast and the fragment
impacts the structure will shake and vibrate, severe crushing of concrete occurs and a
crater forms (spalling) in the front of the concrete; for large penetration, scabbing may
occur at the backside of the wall, or even perforation, with a risk of injury for people
inside the structure.
This thesis is intended to increase the knowledge of reinforced concrete structures
subjected to explosive loading, i.e. effects of blast and fragmentation. A further aim is
to describe and use the non-linear finite element (FE) method for concrete penetration
analyses. Particular attention is given to dynamic loading, where the concrete
behaviour differs compared to static loading. The compressive and tensile strengths
increase due to the strain rate effects. Initial stiffness increases, and moreover the
concrete strain capacity is increased in dynamic loading.
Traditionally, for prediction of the depth of penetration and crater formation from
fragments and projectiles, empirical relationships are used, which are discussed here
together with the effects of the blast wave that is caused by the explosion.
To learn more about the structural behaviour of concrete subjected to severe loading,
a powerful tool is to combine advanced non-linear FE analyses and experiments. A
trustworthy model must be able to capture correct results from several experiments,
including both the depth of penetration and the crater size. In this thesis, FE analyses
of concrete penetration with steel projectiles have been performed and compared to
existing experimental results. By using the non-linear FE program AUTODYN, the
depth of penetration and crater sizing can be predicted.
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Science and Technology Directorate, Infrastructure Protection and
Disaster Management Division.
The views, opinions, findings, conclusions, or recommendations expressed
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Blast-Resistant Highway Bridges: Design and Detailing Guidelines
Author: Eric B. Williamson Oguzhan Bayrak G. Daniel Williams Carrie E. Davis UNIVERSITY OF TEXAS AT AUSTIN Austin, TX Kirk A. Marchand Aldo E. McKay PROTECTION ENGINEERING CONSULTANTS Dripping Springs, TX John Kulicki Wagdy Wassef MODJESKI AND MASTERS, INC. Mechanicsburg, PA | Size: 7.1 MB | Format:PDF | Quality:Unspecified | Publisher: N A T I O N A L C O O P E R A T I V E H I G H W A Y R E S E A R C H P R O G R A M | Year: 2010 | pages: 152
There is a need to protect the nation’s bridges from intentional or accidental explosions. The impacts of these loads on buildings and military structures have been studied for many years, but design for resistance to explosive effects is a new area for bridge engineers. Much research and development has been done on the effectiveness of seismic strengthening details for buildings and bridges, and it has been suggested that these or similar bridge details, used in new construction or as a retrofit, may serve also to resist explosions and provide a predictable level of protection. There is a need to meld knowledge of seismic and extreme-event design for new and existing structures with the equally well-known field of blast-resistant design and the relatively new field of highway bridge blast-resistant design.
Under NCHRP Project 12-72, the research team was selected to develop design and detailing guidelines for improving the structural performance and resistance to explosive effects for new and existing bridges.
This research was performed under NCHRP Project 12-72 by the University of Texas at Austin with the assistance of Protection Engineering Consultants and Modjeski and Masters,
Inc. The report fully documents the research leading to the developed design and detailing guidelines for blast-resistant reinforced concrete bridge columns.
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Author: Air Force Engineering and Services Center. Protective Construction Design Manual, ESL-TR-87-57. Prepared for Engineering and Services Laboratory, Tyndall Air Force Base, FL. (1989). U.S. Department of the Army. Security Engineering, TM 5-853 and Air Force AFMAN 32-1071, Volumes 1, 2, 3, and 4. Washington, DC, Departments of the Army and Air Force. (1994). U.S. Department of the Army. Structures to Resist the Effects of Accidental Explosions, Army TM 5-1300, Navy NAVFAC P-397, AFR 88-2. Washington, DC, Departments of the Army, Navy, and Air Force. (1990). U.S. Department of Energy. A Manual for the Prediction of Blast and Fragment Loading on Structures, DOE/TIC 11268. Washington, DC, Headquarters, U.S. Department of Energy. (1992). U.S. General Services Administration. GSA Security Reference Manual: Part 3 Blast Design and Assessment Guidelines. (2001). Biggs, John M. Introduction to Structural Dynamics. McGraw-Hill. (1964). The Institute of Structural Engineers. The Structural Engineer’s Response to Explosive Damage. SETO, Ltd., 11 Upper Belgrave Street, London SW1X8BH. (1995). Mays, G.S. and Smith, P.D. Blast Effects on Buildings: Design of Buildings to Optimize Resistance to Blast Loading. Thomas Telford Publications, 1 Heron Quay, London E14 4JD. (1995). National Research Council. Protecting Buildings from Bomb Damage. National Academy Press. (1995). | Size: 0.75 MB | Format:PDF | Quality:Unspecified | pages: 14
An explosion is an extremely rapid release of energy in the form of light, heat, sound, and a shock wave. A shock wave consists of highly compressed air traveling radially outward from the source
at supersonic velocities. As the shock wave expands, pressures decrease rapidly (with the cube of the distance) and, when it meets a surface that is in line-of-sight of the explosion, it is reflected and
amplified by a factor of up to thirteen.
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ARCHITECTURAL AND STRUCTURAL DESIGN FOR BLAST RESISTANT BUILDINGS
Author: Zeynep Koccaz Fatih Sutcu Necdet Torunbalci | Size: 0.34 MB | Format:PDF | Quality:Unspecified | Publisher: The 14 th W orld Conference on Earthquake Engineering October 12-17, 2008, Beijing, China | Year: 2008 | pages: 8
The increase in the number of terrorist attacks especially in the last few years has shown that the effect of blast loads on buildings is a serious matter that should be taken into consideration in the design process. Although these kinds of attacks are exceptional cases, man-made disasters; blast loads are in fact dynamic loads that need to be carefully calculated just like earthquake and wind loads.
The objective of this study is to shed light on blast resistant building design theories, the enhancement of building security against the effects of explosives in both architectural and structural design process and the design techniques that should be carried out. Firstly, explosives and explosion types have been explained briefly. In addition, the general aspects of explosion process have been presented to clarify the effects of explosives on buildings. To have a better understanding of explosives and characteristics of explosions will enable us to make blast resistant building design much more efficiently. Essential techniques for increasing the capacity of a building to provide protection against explosive effects is discussed both with an architectural and structural approach.
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(AISC Video) Rules of Thumb for Steel Design - Socrates Ioannides
Size: 186 MB| Quality:VCD| Year:2009
In early times, when computers were neither available nor essential, one objective of steel designers was to discover elegant, simple, and appropriately accurate computational methods. These quick "rules of thumb" became essential resources for structural engineers. And despite the advent of computers, these quick approaches retain their value for: making on-the-spot intelligent decisions, developing a reasonable solution for computer input, and quickly verifying the validity of computer output.
The seminar is presented by Socrates Ioannides from Structural Affliliates International.
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Author: Arsalan Zamir Khan | Size: 4.6 MB | Format:DOC | Quality:Unspecified | Publisher: Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology Jamshoro, Pakistan. | Year: December, 2008. | pages: 47
This project report has been a very enlightening and rewarding experience for us in an area that is of great personal interest. We would like to acknowledge my deep sense of gratitude and indebtedness to our meritorious supervisor, Prof. Dr. Moazzam Baloch with great reverence ecstasy for his encouragement, expert advice, sincere efforts and precious time. He is really a versatile genius of high order. His devoted love is worth appreciable. We couldn’t find the words to express my deepest gratefulness to all our teachers at MUET, JAMSHORO, whose efforts made us what we are today, especially Prof. Dr. Abdul Hakeem Mallah, Chairman Department of Metallurgy and Materials Engineering for his guidance and wisdom throughout our academic carrier, Mr. Nisar Memon for his dedication to teaching and efforts he makes towards explaining the details in every subject he teaches, Mr. Riaz Memon for his moral advices and Mr. Ishfaque Ahmed Isani for his ever-ready help regarding anything computers.
We would also like to acknowledge the help offered to us by Mr. Rehan Majid, Mr. Hamid Raza and Mr. Mehboob Shah of PMO for providing the required materials for the Project and their much valued help.
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Author: John A. Rolfes / Rober A Macrimmon | Size: 0.5 MB | Format:PDF | Quality:Unspecified | Publisher: Iron & Steel Technology | Year: MAY 2007 | pages: 17
This paper discusses current seismic provisions for the design and construction of steel-framed industrial buildings. Also discussed are current design codes for, and the design of, nonbuilding structures often contained within these facilities.
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Friction dissipating joints with slotted bolt holes have been used in concentrically
braced frames (linear sliding) and more recently, in moment resisting frames (rotational sliding).
Such joints have the ability to provide many cycles of ductile energy dissipation with little or no
primary structural damage and permit the decoupling of the strength and stiffness of connected
members. Suggestions are offered on the use of linear sliding joints in K-braced frames where
they could lead to cheaper, stiffer structures with high levels of ductility. Rotating sliding bolted
joints extend the benefits of damage-free energy dissipation to moment-resisting frames. The
decoupling of beam stiffness and end moment strength avoids over-sizing columns to deal with
beam over-strength moments. The performance of a rotational slotted joint having a hierarchy of
two distinct moment levels at which limited rotational slip can occur is discussed. The basic
characteristics of the joint are described and some observations made on the seismic response of
some sample frames to seismic ground motion.
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