Eulerian hydrocode modeling of a dynamic tensile extrusion experiment (u)

Journal Article · Thu Jan 01 04:00:00 EST 2009

OSTI ID:982821

Burkett, Michael W ^[1]; Clancy, Sean P ^[1]

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1. Los Alamos National Laboratory

Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress flow stress model were performed to provide insight into a dynamic extrusion experiment. The dynamic extrusion response of copper (three different grain sizes) and tantalum spheres were simulated with MESA, an explicit, 2-D Eulerian continuum mechanics hydrocode and compared with experimental data. The experimental data consisted of high-speed images of the extrusion process, recovered extruded samples, and post test metallography. The hydrocode was developed to predict large-strain and high-strain-rate loading problems. Some of the features of the features of MESA include a high-order advection algorithm, a material interface tracking scheme and a van Leer monotonic advection-limiting. The Mechanical Threshold Stress (MTS) model was utilized to evolve the flow stress as a function of strain, strain rate and temperature for copper and tantalum. Plastic strains exceeding 300% were predicted in the extrusion of copper at 400 m/s, while plastic strains exceeding 800% were predicted for Ta. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rate were made. Additionally, predictions of the texture evolution (based upon the deformation rate history and the rigid body rotations experienced by the copper during the extrusion process) were compared with the orientation imaging microscopy measurements. Finally, comparisons between the calculated and measured influence of the initial texture on the dynamic extrusion response of tantalum was performed.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 982821
• Report Number(s): LA-UR-09-08026; LA-UR-09-8026
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADVECTION
COPPER
DEFORMATION
EXTRUSION
FLOW STRESS
GRAIN SIZE
METALLOGRAPHY
MICROSCOPY
ORIENTATION
PLASTICS
SIMULATION
STRAIN RATE
STRAINS
TANTALUM
TEXTURE