Blast Resistant Design

Single Abstract

341700 - The Blast Load Acting on a Structure in an Internal Explosion Scenario

Saturday, April 21
8:00 AM - 9:30 AM
Location: 202CD

In the case of a confined explosion, the resulting pressure signals are very complex, mainly because of the interaction between the shock waves and the surrounding room boundaries and the presence of openings. This problem of an internal explosion has been considerably less investigated compared to a free air explosion, and there are open basic questions concerning the parameters that affect the complex pressure-time history and their degree of influence. Ability to predict the pressure-time history with high fidelity is mandatory for any attempt to properly predict the dynamic structural response of the envelope panels and assess the damage caused by the confined explosion. The present research program comprises experimental, analytical, and numerical work.
The experimental part included a series of full scale tests of TNT confined explosions, carried out in a single room cuboid structure, specially designed and constructed to withstand repeated explosions without damage. This study yielded high quality pressure signals at different locations that were used as a data base for comparisons with the computational results and for the examination of the pressure distribution on the test room walls.
The analytical part focused at developing an extensive theoretical model for the prediction of the blast load, mainly characterized by the peak gas pressure and its decay with time. The developed theoretical model for the peak gas pressure prediction is based on the ideal gas equation of state, and is used to predict the gas pressure as function of the exploded charge weight per unit volume of the confined space. The model takes into account thermochemical processes, and uses the laws of thermodynamics to find the blast temperature. Moreover, a method for calculating the gas pressure decay, based on Bernoulli theory, was developed for a partially confined explosion. The derived formulas are found to yield gas pressure predictions that agree well with our experimental results and with experimental results available in the open literature. These new theoretical approaches explain numerous experimental results and agree very well with empirical results.
The experimental results were compared with numerical calculations performed using AUTODYN hydro-dynamic code, aiming at simulation of the experimental test cases. It clarified the behavior of the blast waves, the gas pressure and the effect of the detonation products afterburning on the acting pressures. According to the analytical work, the afterburning energy release, as a result of exothermic reaction of the detonation products with the oxygen in the air, at certain temperature conditions, helped to improve the numerical simulations when this afterburning energy was included into the equation of state of the explosive during an appropriate time interval.
This study contributes to understanding the relationship between explosion data and its results, and has a great value in advancing knowledge on this subject. Beyond that, it contributes to more accurately design of buildings subjected to such conditions discussed, which today are designed with simplified and approximate design tools which their suitability is questionable, as shown in this study.

Idan Edri

Doctoral Student
Technion

Idan is a doctoral student at the civil engineering faculty at the Technion Israel Institute of Technology, with research expertise in blast response of structures. He has conducted numerous experimental, analytical, and numerical studies in the area. He is reporting on a large scope research on interior explosion and presently already studies the blast respose of masonry walls.

Presentation(s):

Send Email for Idan Edri

Vladimir Feldgun

Senior researcher
Technion

Dr Feldgun is a senior researcher with background in mechanics and mathematics. He has been involved in numerous studies in the field of shock and impact. He has accumulated a respected list of publications in leading journals in the field.

Presentation(s):

Send Email for Vladimir Feldgun

Yuri Karinski

Senior researcher
Technion

Dr Karinski is a senior researcher with background in mechanics and mathematics. He has been involved in numerous studies in the field of shock and impact. He has accumulated a respected list of publications in leading journals in the field.

Presentation(s):

Send Email for Yuri Karinski

David Yankelevsky

Professor of Structural Engineering
Technion

Prof Yankelevsky is a senior Faculty in Structural Engineering with expertise in structural response to extreme loads, damage and failure. He had served as Head of the National Building Research Institute for 14 years.

Presentation(s):

Send Email for David Yankelevsky


Assets

341700 - The Blast Load Acting on a Structure in an Internal Explosion Scenario



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for The Blast Load Acting on a Structure in an Internal Explosion Scenario