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Sandia Fracture Challenge 3: detailing the Sandia Team Q failure prediction strategy

International Journal of Fracture

Karlson, K.N.; Alleman, Coleman; Bays, Nathan R.; Manktelow, Kevin; Ostien, Jakob T.; Stender, Michael; Stershic, Andrew J.; Veilleux, Michael G.

The third Sandia Fracture Challenge highlighted the geometric and material uncertainties introduced by modern additive manufacturing techniques. Tasked with the challenge of predicting failure of a complex additively-manufactured geometry made of 316L stainless steel, we combined a rigorous material calibration scheme with a number of statistical assessments of problem uncertainties. Specifically, we used optimization techniques to calibrate a rate-dependent and anisotropic Hill plasticity model to represent material deformation coupled with a damage model driven by void growth and nucleation. Through targeted simulation studies we assessed the influence of internal voids and surface flaws on the specimens of interest in the challenge which guided our material modeling choices. Employing the Kolmogorov–Smirnov test statistic, we developed a representative suite of simulations to account for the geometric variability of test specimens and the variability introduced by material parameter uncertainty. This approach allowed the team to successfully predict the failure mode of the experimental test population as well as the global response with a high degree of accuracy.

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TYPE Journal Article YEAR 2019
DOIOSTIScopus

Ductile Fracture - Gradient Regularization

Ostien, Jakob T.; Talamini, Brandon; Stershic, Andrew J.

Nuclear weapons alteration (ALT) and life extension programs (LEP) are of primary interest to the mission of Sandia National Laboratories. These programs continue to require experimental exploration and computational simulation of ductile failure scenarios to address qualification. Therefore, we invest in generating understanding about ductile failure as demonstrated though experimental procedures and computational simulation of engineering environments. In particular, we study an approach to ductile failure that incorporates the notion of phase-field fracture into our models of inelasticity appropriate for structural alloys. This report covers the formulations of the constitutive model and fracture models used within the phase-field approach and provides some numerical examples highlighting features and the state of the capability.

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TYPE SAND Report YEAR 2018
DOIOSTI
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Results 26–42 of 42
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