Discussion on “Active aeroelastic control of 2-D wing-flap systems operating in an incompressible flowfield and impacted by a blast pulse” by Librescu et al., Journal of Sound and Vibration 283 (3–5) (2005) 685–706

2013 ◽  
Vol 332 (13) ◽  
pp. 3351-3358 ◽  
Author(s):  
S. Mozaffari-Jovin ◽  
R.D. Firouz-Abadi ◽  
J. Roshanian ◽  
A. Ghaffari
Keyword(s):  
Blast Pulse

Impact and Blast Pulse: Improving Energy Absorption of Fibre-Reinforced Composites Through Optimized Tailoring

2006 ◽  
Author(s):  
Ugo Icardi ◽  
Laura Ferrero
Keyword(s):  
Energy Absorption ◽  
Transverse Shear ◽  
Shear Stresses ◽  
Current Production ◽  
Transverse Shear Stresses ◽  
Production Technologies ◽  
Definition Of ◽  
Incoming Energy ◽  
Blast Pulse ◽  
Delamination Damage

This paper tries to conjugate an improvement of stiffness and delamination damage resistance. A number of published results allow us to guess the existence of fibre orientations that are a good compromise for an optimal absorption of the incoming energy and for maintaining of a high stiffness. Optimal absorption is herein intended as a way not involving weak properties, such as interlaminar strength. We seek for an optimal orientation of reinforcement fibres through definition of stationary conditions for bending and shear energy contributions under in-plane variation of plate stiffness coefficients. Our goal is to tune the energy absorption as desired. Two kinds of optimized layers are studied, that are compatible with current production technologies: type 1 reduces bending without substantially increasing the transverse shear stresses, type 2 reduces transverse shear stresses without substantially increasing deflections. Incorporation into the laminates of couples of these layers with opposite features and the same mean properties of those they substitute allows an energy transfer from an unwanted to a wanted mode, as shown by the numerical applications. In this way, the deflections and the stresses inducing delamination damage of laminates subjected to impact and blast pulse loads were reduced, while damping should not substantially change since the variation of the orientation of fibres lies in a range where mild variations of it are induced.

Performance of Structural Blast Mitigation Measure for Oil and Gas Industrial Facilities

2019 ◽  
Vol 812 ◽  
pp. 92-99 ◽  
Author(s):  
Damjan Cekerevac ◽  
Constanca Rigueiro ◽  
Eduardo Pereira
Keyword(s):  
Finite Element Modelling ◽  
Oil And Gas ◽  
Traditional Approach ◽  
Industrial Facilities ◽  
Stiffened Panels ◽  
Local Element ◽  
Blast Response ◽  
Alternative Materials ◽  
Reaction Forces ◽  
Blast Pulse

The response of the bulkhead type of blast wall under deflagration blast pulse was studied using finite element modelling software. The behavior of unstiffened and stiffened panels was analyzed. The study aimed at determining the effect of plate and stiffener thicknesses on energy dissipation and distribution of reaction forces. This was carried out in order to optimize the response of the primary steelwork through typological and geometrical modifications of the local element. Furthermore, novel strategies for the improvement of the blast response were introduced with a focus to use alternative materials and innovative connections. The latter was assessed numerically using a simplified model and its benefits were analyzed by comparing with the traditional approach.

Possibilistic Analysis of Structural Systems Subjected to Blast Loads

2003 ◽  
Author(s):  
Hari B. Kanegaonkar
Keyword(s):  
Pulse Duration ◽  
Rise Time ◽  
Peak Pressure ◽  
Pressure Rise ◽  
Structural Response ◽  
Offshore Structures ◽  
Blast Loads ◽  
Safety Level ◽  
Ignition Point ◽  
Blast Pulse

The accidental release of the hydrocarbons and the possibility of resulting explosion have to be taken into account while designing the topside systems of the offshore structures. Determination of design explosion loads for the topside structures is a complex task since it involves several sources of uncertainty. Dimensioning of blast loads is important in achieving the desired safety level against the structural failure and related consequences. The design loads must incorporate uncertainties due to variability in the ignition point location, the type of ignition source, the volume of the gas released and the characteristics of the gas cloud etc. These uncertainties which are not statistical in nature may not be categorised as random or probabilistic but are cognitive and fuzzy in nature. The probabilistic framework for structural analysis subjected to blast loads could be quite cumbersome due to high number of uncertain variables and complex interdependency. The uncertainty in the load and corresponding uncertainty in the structural response can either be predicted from variations in the uncertain load parameters — a sensitivity evaluation or through a compact “possibilistic analysis”. The blast loads are usually defined as a triangular pulse through peak pressure, rise time and the blast pulse duration as the parameters. In the present investigation, the parameters in the triangular blast load description are assumed fuzzy. The peak pressure, rise time and blast pulse duration are defined using triangular fuzzy numbers. The possibilistic dynamic response of simple structural system — beam — used in the blast wall is obtained using single-degree of freedom approximation. It is shown that the possibilistic response provides rational decision making tool to arrive at desired safety level.

Clamped Circular Rigid-Plastic Plates Under Blast Loading

1966 ◽  
Vol 33 (2) ◽  
pp. 256-260 ◽  
Author(s):  
A. L. Florence
Keyword(s):  
Theoretical Study ◽  
Plastic Material ◽  
Blast Loading ◽  
Rectangular Pulse ◽  
Circular Plates ◽  
Rigid Plastic ◽  
Central Deflection ◽  
Rigid Plastic Material ◽  
Blast Pulse

A theoretical study is made of clamped circular plates of rigid-plastic material subjected to blast loading uniformly distributed over the surface. The dependence of the permanent central deflection on pressure and impulse is obtained when the blast pulse is taken as a rectangular pulse.

scholarly journals On firework blasts and qualitative parameter dependency

2016 ◽  
Vol 472 (2185) ◽  
pp. 20150720 ◽  
Author(s):  
T. I. Zohdi
Keyword(s):  
Mathematical Model ◽  
Kinetic Energy ◽  
Time Evolution ◽  
Three Dimensional ◽  
Simplifying Assumptions ◽  
Released Energy ◽  
Detonation Energy ◽  
Parameter Dependency ◽  
Blast Pulse ◽  
Qualitative Parameter

In this paper, a mathematical model is developed to qualitatively simulate the progressive time-evolution of a blast from a simple firework. Estimates are made for the blast radius that one can expect for a given amount of detonation energy and pyrotechnic display material. The model balances the released energy from the initial blast pulse with the subsequent kinetic energy and then computes the trajectory of the material under the influence of the drag from the surrounding air, gravity and possible buoyancy. Under certain simplifying assumptions, the model can be solved for analytically. The solution serves as a guide to identifying key parameters that control the evolving blast envelope. Three-dimensional examples are given.

Estimation of seabed reflection properties from direct blast pulse shape

2003 ◽  
Vol 114 (4) ◽  
pp. 2450-2450
Author(s):  
Mark K. Prior ◽  
Christopher H. Harrison
Keyword(s):  
Pulse Shape ◽  
Blast Pulse
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