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Md Asif Akbari, [email protected]
Behavior Of Reinforced Concrete Beams Under Different Kinds Of Blast Loading And Their Analysis
Md Asif Akbari(B.Tech 7th sem), Student Coordinator (T&P)
[email protected]+91-7735168092
School of Civil Engineering. KIIT University, Bhubaneswar, Odisha, India
Md Asif Akbari, [email protected]
INTRODUCTION• One of the most popular design issue.• Terror attacks and accidents.• Subject is popularly applied in modern and
important buildings.• Emerging branch in the field of structural
engineering
Md Asif Akbari, [email protected]
Reasons for concern.•Today the modern explosive devices are being used in majority of terrorist attacks because of the ease of access of information on the construction of bomb devices, relative ease of manufacturing, mobility and portability, coupled with significant property damage and injuries. •No one can deny the strength of these attacks after 09/11 World Trade Centre bombing.
Md Asif Akbari, [email protected]
Principles of design•Minimize the quantity and hazard of broken glass and blast induced debris•Facilitate rescue and recovery operation with adequate time of evacuation of occupants.•To reduce the pressure due to blast loading.•Maintain safe separation of attackers and targets i.e. STAND-OFF zones.•Design to sustain and contain certain amount of bomb damage. Avoid progressive collapse of the building.•Allow for limited localized damage of members•Facilitate rescue and recovery operation with adequate time of evacuation of occupants.
Md Asif Akbari, [email protected]
Blast load definition•Air BrustWhen an explosion occurs nearby to and above a building structure such that no amplification of the initial shock wave occurs between the explosive charge and the structure, then the blast is called free air blast.
Md Asif Akbari, [email protected]
Characteristics of Air brustAt the arrival time tA, following the explosion, pressure at that position suddenly increases to a peak value of overpressure, Pso, over the ambient pressure, Po. The pressure then decays to ambient level at time td, then decays further to an under pressure Pso - (creating a partial vacumn) before eventually returning to ambient conditions at time td + td -. The quantity Pso is usually referred to as the peak side-on overpressure, incident peak overpressure or merely peak overpressure
Md Asif Akbari, [email protected]
Surface brust
A ground burst is the detonation of an explosive device such as an artillery shell, nuclear weapon or air-dropped bomb that explodes upon hitting the ground. These weapons are set off by that are activated when the weapon strikes the ground or something equally hard, such as a concrete building.
Md Asif Akbari, [email protected]
Characteristics of surface brust
In surface blast unlike the air blast the wave combines to create the total effect of the which is the combination of reflected wave produced after the reflection from the ground and the initial wave which is hemispherical in shape
Md Asif Akbari, [email protected]
DIFFERENT MODELSSingle digree of freedom model
It is the simplest vibratory system
that can be described by a
single mass connected to a
spring (and possibly a dashpot).
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Finite element model
This model is based on multi degree of freedom (MDOF) , in this model beam is devided into finite number of elements and those elements are further subdivided into fibre, this helps to take account into the variation along the depth of specimen. This modeling is generally done by ABAQUS.
Md Asif Akbari, [email protected]
ConclusionThe lack of relevant code is the major concern behind the ignorance of this phenomena while designing the structure. In our review work we have found that the various kind of loading phenomena the non- linear analysis of beam column agrees satisfactorily with the finite element model as analyzed on ABAQUS.
