title: Evaluation of overpressure prediction models for air blast above the triple point.
abstract: The increase of blast exposures leads to the need for better assessment of the blast threat. Empirical models describing the blast propagation in ideal conditions as free-field or surface detonations are commonly employed, but in some configurations the ground-reflected shock should be treated explicitly. Empirical models permit the prediction of the blast characteristics with the ground-reflected shock. The present study uses some original experimental data to evaluate the accuracy of the predicted overpressure with time regarding the reflected shock characteristics. Three methods are tested. The first method, called method of images (MOI) and linearly adding a virtual ground-symmetrical source blast to the free-field blast, is quick but lacks accuracy regarding the reflected shock characteristics. The second method, based on the LOAD_BLAST_ENHANCED function of the commercial LS-DYNA framework, better captures the reflected shock compared to the MOI, but the overall differences with experimental data are of the same order of magnitude as for the MOI. An original fit is introduced, based on standard physical parameters. The accuracy of this fit on the reflected shock characteristics, and the better match with the overall overpressure time series, shows its potential as a new empirical blast predicting tool.
authors.affiliation: French-German Research Institute of Saint-Louis, 5 rue du Général Cassagnou, 68300 Saint-Louis, France. Electronic address: loic.ehrhardt@isl.eu.
authors.forename: L
authors.initials: L
authors.lastname: Ehrhardt
authors.affiliation: French-German Research Institute of Saint-Louis, 5 rue du Général Cassagnou, 68300 Saint-Louis, France; Strasbourg University, Icube, UMR 7357 Multiscale Materials and Biomechanics, 2 rue Boussingault, 67000 Strasbourg, France.
authors.forename: J
authors.initials: J
authors.lastname: Boutillier
authors.affiliation: French-German Research Institute of Saint-Louis, 5 rue du Général Cassagnou, 68300 Saint-Louis, France.
authors.forename: P
authors.initials: P
authors.lastname: Magnan
authors.affiliation: Strasbourg University, Icube, UMR 7357 Multiscale Materials and Biomechanics, 2 rue Boussingault, 67000 Strasbourg, France.
authors.forename: C
authors.initials: C
authors.lastname: Deck
authors.affiliation: French-German Research Institute of Saint-Louis, 5 rue du Général Cassagnou, 68300 Saint-Louis, France.
authors.forename: S
authors.initials: S
authors.lastname: De Mezzo
authors.affiliation: Strasbourg University, Icube, UMR 7357 Multiscale Materials and Biomechanics, 2 rue Boussingault, 67000 Strasbourg, France.
authors.forename: R
authors.initials: R
authors.lastname: Willinger
authors.affiliation: French-German Research Institute of Saint-Louis, 5 rue du Général Cassagnou, 68300 Saint-Louis, France.
authors.forename: S
authors.initials: S
authors.lastname: Cheinet
keywords: Blast overpressure; Empirical methods; Experimental data; Triple point