Sandia Labs FY21 LDRD Annual Report

FY21 ANNUAL REPORT

Revolutionizing mechanical part design through a unique computational engineering design tool. Mechanical part designers and analysts are currently burdened by a traditional design-then-simulate iterative process that is extremely costly, time consuming, sub-optimal, and error prone. To address this, a research team developed a novel capability for solving inverse, topology optimization and optimal design problems where the physics is governed by nonlinear solid mechanics with contact and friction. Machine-learning based reduced-order modeling techniques were developed by Georgia Tech to complement the design optimization. In addition to enabling improved engineering designs, this computational tool significantly accelerates and improves the way mechanical part design is performed , which will help the national security enterprise respond more quickly to changing design requirements. (PI: Michael Tupek) Proof of concept provides foundation for future testing of reentry devices. Sandia currently cannot fully test reentry vehicles in a complex and combined representative environment. This LDRD project tightly integrated experiments with high-fidelity simulations to provide proof-of-concept for a new test capability. The high-risk, high-reward idea introduced a tailored explosive shock loading to Sandia’s Superfuge facility to enhance its combined inertial and vibration environments with a hostile blast. New Mexico Tech, an academic partner, conducted blast induced shock loading experiments with the assistance of graduate student, James Reeves, under the supervision of his

professor, Dr. Michael Hargather. These experiments enabled a modest modeling/simulation/testing plus validation and verification effort. The successful combined environment test capability that could result from this proof-of-concept will drastically increase the agility of design, development, and qualification activities, and strengthen the nation’s overall engineering capabilities. (PI: Timothy Miller)

(Top) Schlieren images showing a 1-gram-pentaerythritol tetranitrate blast on a 6-inch plate (left) and on a 6-inch hemisphere (right). (Bottom) Zapotec simulation and Schlieren video side-by-side 180 microseconds after detonation.

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LABORATORY DIRECTED RESEARCH & DEVELOPMENT