Close-Range Blast Effects on Small Square Clamped Plates Made from Aluminum 6061-T6

• Published in: Journal of dynamic behavior of materials 2017, Vol.3 (1), p.83-99
• Main Authors: Toussaint, Geneviève, Bouamoul, Amal
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Compression tests; Materials Science; Metallic Materials; Solid Mechanics; Strain rate
• ISSN: 2199-7446; 2199-7454
• DOI: 10.1007/s40870-017-0096-4

The main objective of this paper is to describe the methodology followed to verify and validate (V&V) a finite element model developed to simulate a spherical air blast on a square aluminum (Al) 6061-T6 plate. In order to have confidence in the material model and properties, the first part of this paper provides a brief review of the Defence Research and Development Canada split Hopkinson pressure bar (SHPB) facility and presents the tests performed on Al 6061-T6 specimens at different strain rates. The obtained high strain rate compression tests combined to the available published data in the literature allowed us to calibrate the parameters of the Johnson–Cook constitutive material model of the Al 6061-T6. Finite element simulations of an axisymmetric two-dimensional model were then performed to reproduce the SHPB experiments and thus validated the material properties obtained previously. The second part of this paper describes the finite element model developed to simulate the effects of a spherical close-range air blast on a predefined square target. For V&V purpose, the simulations results were compared to a wide range of experiments where the mass of the explosive was varied between 15 and 220 g and the target plate had three different thickness’ either 1.524 mm (0.06 in), 2.286 mm (0.09 in) and 3.048 mm (0.12 in). As well, the stand-off distance between the center of the C-4 explosive and the surface of the plate was varied between 10, 20 and 30 cm. Finally, the permanent midpoint deflection and the total impulse obtained numerically were compared to the experimental results and have shown good agreement in general. The methodology followed in this study required a great effort from the experimental and numerical sides but at the end, provided a set of Johnson–Cook material parameters for Al 6061-T6 and a blast loading model that can be further used to reproduce accurately the deformation of various structures made from this material.