Des essais à échelle réduite pour déduire les chargements d'effets de souffle (détonation)
Titre du congrès :SUSI 2008 - Tenth International Conference on Structures Under Shock and Impact
Ville du congrès :Algarve
Date du congrès :14/05/2008
The definition of blast loads applying on a complex geometry structure is still nowadays a hard task when numerical simulation is used, essentially because of the different scales involved : as a matter of fact, modeling the detonation of a charge and its resulting load on a structure requires to model the charge itself, the structure and air surrounding, which rapidly leads to large size models on which parametrical studies become unaffordable. So, on the basis of the Crank-Hopkinson's law, an experimental set-up has been developed to support reduced scale structures as well as reduced scale detonating solid charges. As a final objective, the set up must be used to produce the entry data for numerical assessments of the structure résistance.
This set-up is composed of a modular table, sensors and targets and has been designed to conduct non destructive studies. In the context of security, the general aim is to study the effects of detonation shock waves in the vicinity of industrial installations and to test various shock wave mitigation means that could be implemented for the protection of facilities in sensitive locations. Especially, the setup offers the possibility to measure the loading in terms of pressure-time curves, even for very complex situations like multiple reflections, combination and diffraction.
The present paper summarizes the development of the set up as well as the first tests performed. The main features of the table, instrumentation and pyrotechnies are given. Also the paper summarizes a first qualification tests campaign that has been conducted in year 2006. In this campaign, free field blast tests (i.e. blast tests performed without structures) have been conducted. Overpressure maxima, arrival time of the shock wave and impulse of pressure time histories are presented as adimensionnal characteristics of the pressure time history and have been found in good agreement with reference curves available from the open literature.