A split Hopkinson pressure bar (SHPB) set-up was used to investigate the dynamic constitutive behaviour of commercial aluminium alloys both experimentally and numerically. The study was conducted in a 500–10 000 s×1 strain rate regime. Both regular solid and modified hollow transmission bars were employed in realizing this strain rate regime. Four different aluminium alloys, namely 7075-T4, 2024-T3, 6061-T6, and 5182-O, were considered for investigation. A copper-110 alloy pulse shaper was used to obtain better force equilibrium conditions at the bar–specimen interfaces. A plastic kinematic model was used to model the rate-dependent behaviour of aluminium alloys using commercially available ANSYS LS-DYNA software. Compared with the quasi-static condition, all four alloys showed a slight rate dependency with an increased flow stress ranging from 50 to 100 MPa at much higher strain rates. It was established from the final results that the experimentally determined dynamic constitutive behaviour matches very well with the numerical value in a 2000–5000 s×1 strain rate regime.

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The dynamic behavior of Hastelloy ® X plates subjected to normal and oblique shock loading was studied both experimentally and numerically. A series of experiments was conducted on Hastelloy ® X plates at room temperature under fixed boundary conditions using a shock tube apparatus. High-speed digital cameras were used to obtain the real-time images of the specimen during the shock loading. Digital Image Correlation (DIC) technique was utilized to obtain 3D deformations of the plates using stereo-images of the specimen. The numerical modeling utilized the finite element software package Dynamic System Mechanics Analysis Simulation (DYSMAS) which includes both the structural analysis as well as the fluid-structure interaction to study the dynamic behavior of the specimen under given loads. Experimentally obtained pressure-time profiles were used as a reference in numerical modeling. It was observed that the lower angles of shock incidence caused more deformation on the specimen. Additionally for oblique shocked specimens, the deformation was observed to initiate from the edge nearer to the muzzle. The results from the numerical simulations were validated with the experimental data, and showed excellent correlation for all cases.

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A series o f experiments were conducted to determine the John son-Cook parameters for three different cast aluminum alloys, namely, A356, A357, and F357. Room temperature compression experiments were performed under varying rates o f loading rang ing from 10 3 s 1 to 5000 s 1. High temperature compression (235 °C and 435 °C) experiments were performed at an average strain rate o f 5000 s~'. A split Hopkinson pressure bar (SHPB) apparatus was utilized in conjunction with an induction coil heat ing system for applying dynamic loading at elevated temperatures. In addition, experiments were performed under high strain rate tensile loading using tensile SHPB apparatus, and the fractured specimens were examined under scanning electron microscope (SEM) to understand the failure modes in these alloys. High speed photography was used to capture the chronological pro gression o f the deformation under dynamic tensile loading. The results indicated that all the three cast aluminum alloys were sen sitive to strain rate and temperature. A356 exhibited the least value of flow stress under both static and dynamic loading condi tions, and the highest elongation before break under dynamic tensile loading. The SEM images o f the fractured specimens under dynamic tensile loading showed characteristics o f transcrystalline ductile fracture in these cast aluminum alloys.