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Parallel Solver Framework for Mixed-Integer PDE-Constrained Optimization

Phillips, Cynthia A.; Chatter, Michelle; Eckstein, Jonathan; Erturk, Alper; El-Kady, Ihab F.; Gerbe, Romain; Kouri, Drew P.; Loughlin, William; Reinke, Charles M.; Rokkam, Rohith; Ruzzene, Massimo; Sugino, Christopher; Swanson, Calvin; Van Bloemen Waanders, Bart

ROL-PEBBL is a C++, MPI-based parallel code for mixed-integer PDE-constrained optimization (MIPDECO). In these problems we wish to optimize (control, design, etc.) physical systems, which must obey the laws of physics, when some of the decision variables must take integer values. ROL-PEBBL combines a code to efficiently search over integer choices (PEBBL = Parallel Enumeration Branch-and-Bound Library) and a code for efficient nonlinear optimization, including PDE-constrained optimization (ROL = Rapid Optimization Library). In this report, we summarize the design of ROL-PEBBL and initial applications/results. For an artificial source-inversion problem, finding sources of pollution on a grid from sparse samples, ROL-PEBBLs solution for the nest grid gave the best optimization guarantee for any general solver that gives both a solution and a quality guarantee.

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TYPE SAND Report YEAR 2021
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Massively Parallel Capability in Sierra/SD for Simulation Vibration with Piezoelectrics

Bunting, Gregory; Smith, Chandler; Walsh, Timothy

Sierra/SD is an engineering structural dynamics code that provides Sandia and other customers a tool to model structural and acoustic physics on large complex physical systems using massively parallel processing. This report provides a detailed overview on Sierra/SD’s most recent physics package: coupled electro-mechanical physics. This capability uses the finite element method to model coupled electro-mechanical physics exhibited by piezoelectric materials. This report provides an applications overview, theory overview, and verification examples demonstrating the electro-mechanical physics modeling capabilities of Sierra/SD.

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TYPE SAND Report YEAR 2021
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Innovation

Ackermann, Mark R.

Innovation is a highly overused buzzword in government offices and corporate America. Just like leadership, innovation is something that organizations realize they need, but often are frustrated in their efforts to achieve. Making matters worse, the definition of innovation changes with the user and the context. Simply put, innovation is change and change for any organization is difficult. This study examines the topic of innovation and pays special attention to what works, what does not work, and the basic principles governing how one might go about innovating. As leadership is critical to any successful innovation effort, special attention is given to leading change and leading innovation. ''The reasonable man adapts himself to the world; the unreasonable one persists to adapt the world to himself. Therefore, all progress depends on the unreasonable man.'' - George Bernard Shaw

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TYPE SAND Report YEAR 2021
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Structure-Property Relationships of Additively Manufactured Ni-Nb Alloys [Slides]

Jones, Morgan; Kustas, Andrew B.; Delrio, F.W.; Pegues, Jonathan W.; Lu, Ping; Chandross, Michael E.; Argibay, Nicolas

In this work, scratch and nanoindentation testing was used to determine hardness, fracture toughness, strain rate sensitivity, and activation volumes on additively manufactured graded and uniform Ni-Nb bulk specimens. Characterization showed the presence of a two phase system consisting of Ni3Nb and Ni6Nb7 intermetallics. Intermetallics were multimodal in nature, having grain and cell sizes spanning from a few nanometers to 10s of micrometers. The unique microstructure resulted in impressively high hardness, up to 20 GPa in the case of the compositionally graded sample. AM methods with surface deformation techniques are a useful way to rapidly probe material properties and alloy composition space.

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TYPE Conference Presenation YEAR 2021
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DPC Direct Disposal R&D Independent Technical Review: Plan

Hardin, Ernest

Developing and evaluating approaches for direct geologic disposal of commercial spent nuclear fuel (SNF) in dual-purpose canisters (DPCs) is a cross-cutting multi-disciplinary activity that is directly tied to the implementation of DPCs by the nuclear industry. The ultimate goal of the DPC direct disposal R&D program is to facilitate and maximize safe, cost-effective, licensed direct disposal. Independent Technical Review (ITR) is needed to maximize the impact of the R&D program on future implementation. The review will involve a team of experts representing the nuclear industry, repository sciences, and licensing. The team will be charged to review a set of representative technical reports and other information, and answer a set of questions that focus on R&D steering.

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TYPE Other Report YEAR 2021
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Rapid QSTS Simulations for High-Resolution Comprehensive Assessment of Distributed PV

Broderick, Robert J.; Reno, Matthew J.; Lave, Matt; Azzolini, Joseph A.; Blakely, Logan; Galtieri, Jason; Mather, Barry; Weekley, Andrew; Hunsberger, Randolph; Chamana, Manohar; Li, Qinmiao; Zhang, Wenqi; Latif, Aadil; Zhu, Xiangqi; Grijalva, Santiago; Zhang, Xiaochen; Deboever, Jeremiah; Qureshi, Muhammad U.; Therrien, Francis; Lacroix, Jean-Sebastien; Li, Feng; Belletete, Marc; Hebert, Guillaume; Montenegro, Davis; Dugan, Roger

The rapid increase in penetration of distributed energy resources on the electric power distribution system has created a need for more comprehensive interconnection modeling and impact analysis. Unlike conventional scenario-based studies, quasi-static time-series (QSTS) simulations can realistically model time-dependent voltage controllers and the diversity of potential impacts that can occur at different times of year. However, to accurately model a distribution system with all its controllable devices, a yearlong simulation at 1-second resolution is often required, which could take conventional computers a computational time of 10 to 120 hours when an actual unbalanced distribution feeder is modeled. This computational burden is a clear limitation to the adoption of QSTS simulations in interconnection studies and for determining optimal control solutions for utility operations. The solutions we developed include accurate and computationally efficient QSTS methods that could be implemented in existing open-source and commercial software used by utilities and the development of methods to create high-resolution proxy data sets. This project demonstrated multiple pathways for speeding up the QSTS computation using new and innovative methods for advanced time-series analysis, faster power flow solvers, parallel processing of power flow solutions and circuit reduction. The target performance level for this project was achieved with year-long high-resolution time series solutions run in less than 5 minutes within an acceptable error.

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TYPE SAND Report YEAR 2021
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Library of Advanced Materials for Engineering (LAMÉ) 5.0

Lester, Brian T.; Scherzinger, William M.; Long, Kevin N.; Reedlunn, Benjamin; Vignes, Chet

Accurate and efficient constitutive modeling remains a cornerstone issue for solid mechanics analysis. Over the years, the LAMÉ advanced material model library has grown to address this challenge by implementing models capable of describing material systems spanning soft polymers to stiff ceramics including both isotropic and anisotropic responses. Inelastic behaviors including (visco)plasticity, damage, and fracture have all incorporated for use in various analyses. This multitude of options and flexibility, however, comes at the cost of many capabilities, features, and responses and the ensuing complexity in the resulting implementation. Therefore, to enhance confidence and enable the utilization of the LAMÉ library in application, this effort seeks to document and verify the various models in the LAMÉ library. Specifically, the broader strategy, organization, and interface of the library itself is first presented. The physical theory, numerical implementation, and user guide for a large set of models is then discussed. Importantly, a number of verification tests are performed with each model to not only have confidence in the model itself but also highlight some important response characteristics and features that may be of interest to end-users. Finally, in looking ahead to the future, approaches to add material models to this library and further expand the capabilities are presented

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TYPE SAND Report YEAR 2021
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Large-Scale Trajectory Analysis via Feature Vectors

Foulk, James W.; Jones, Jessica L.; Newton, Benjamin D.; Wisniewski, Kyra L.; Wilson, Andrew T.; Ginaldi, Melissa J.; Waddell, Cleveland A.; Goss, Kenneth; Ward, Katrina J.

The explosion of both sensors and GPS-enabled devices has resulted in position/time data being the next big frontier for data analytics. However, many of the problems associated with large numbers of trajectories do not necessarily have an analog with many of the historic big-data applications such as text and image analysis. Modern trajectory analytics exploits much of the cutting-edge research in machine-learning, statistics, computational geometry and other disciplines. We will show that for doing trajectory analytics at scale, it is necessary to fundamentally change the way the information is represented through a feature-vector approach. We then demonstrate the ability to solve large trajectory analytics problems using this representation.

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TYPE Other Report YEAR 2021
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PV CAMPER Annual Report 30 December 2020

Burnham, Laurie

The objective of the Photovoltaic Collaborative to Advance Multi-climate and Performance Research (PVCAMPER) is to: 1) Build and maintain a multi-climate research platform to enable pioneering photovoltaic research; 2) Validate the performance of emerging technologies in specific climates; 3) Help accelerate the world’s transition to a solar-intensive economy. Our focus in achieving those goals is to foster collaborative research and to build an international organization dedicated to improving data quality, minimizing measurement uncertainty and exchanging best practices related to PV performance.

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TYPE Other Report YEAR 2021
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Sierra/SD - How To Manual, 5.0

Bunting, Gregory; Crane, Nathan K.; Day, David; Dohrmann, Clark R.; Ferri, Brian; Hardesty, Sean; Lindsay, Payton; Miller, Scott T.; Stevens, Brian; Walsh, Timothy

The “how to” document guides the user through complicated aspects of software usage. It should supplement both the User’s manual and the Theory document, by providing examples and detailed discussion that reduce learning time for complex set ups. These documents are intended to be used together. We will not formally list all parameters for an input here – see the User’s manual for this. All the examples in the “How To” document are part of the Sierra/SD test suite, and each will run with no modification. The nature of this document casts together a number of rather unrelated procedures. Grouping them is difficult. Please try to use the table of contents and the index as a guide in finding the analyses of interest.

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TYPE SAND Report YEAR 2021
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A Taxonomy for Classification and Comparison of Dataflows for GNN Accelerators

Garg, Raveesh; Qin, Eric; Martinez, Francisco M.; Guirado, Robert; Jain, Akshay; Abadal, Sergi; Abellan, Jose L.; Acacio, Manuel E.; Alarcon, Eduard; Rajamanickam, Sivasankaran; Krishna, Tushar

Recently, Graph Neural Networks (GNNs) have received a lot of interest because of their success in learning representations from graph structured data. However, GNNs exhibit different compute and memory characteristics compared to traditional Deep Neural Networks (DNNs). Graph convolutions require feature aggregations from neighboring nodes (known as the aggregation phase), which leads to highly irregular data accesses. GNNs also have a very regular compute phase that can be broken down to matrix multiplications (known as the combination phase). All recently proposed GNN accelerators utilize different dataflows and microarchitecture optimizations for these two phases. Different communication strategies between the two phases have been also used. However, as more custom GNN accelerators are proposed, the harder it is to qualitatively classify them and quantitatively contrast them. In this work, we present a taxonomy to describe several diverse dataflows for running GNN inference on accelerators. This provides a structured way to describe and compare the design-space of GNN accelerators.

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TYPE Other Report YEAR 2021
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DPC Disposal Concepts of Operations. Final Report

Hardin, Ernest

The U.S. Department of Energy supports an R&D program for evaluating approaches to direct disposal of commercial spent fuel in dual-purpose canisters (DPCs). The major thrusts include alternative measures for treating the possibility of internal criticality events in DPC-based waste packages after thousands of years in a repository. These measures include: 1) injectable fillers, 2) analysis of the consequences of criticality events in a repository should they occur, and 3) options for modifying fuel assemblies or baskets in DPCs at the time they are loaded. This report presents a snapshot of progress in each of these areas drawing on deliverable reports generated during FY18 through FY20. Another aspect of the R&D program is to develop concepts of operations for repositories that would permanently dispose of DPC-based waste packages, considering different generic host media (not site-specific). The idea is to examine whether the disposal of large, heavy, heat-generating waste packages is technically feasible, and to identify the engineering challenges that would arise during implementation of the different disposal concepts. Descriptions of repository features are presented for repositories in salt media, argillite (clay/shale) media, crystalline (e.g., granitic) media, and unsaturated media (considering either alluvium or hard rock). Thermal management criteria for each concept are presented in terms of the maximum waste package thermal power at emplacement, when the repository could be opened, and the duration of repository emplacement operations. The overall message of this report is that direct disposal of commercial spent fuel is technically feasible in different types of geologic host media, but that thermal management and postclosure criticality impose different constraints on each concept. Engineering challenges are recognized and discussed. Treatment of postclosure criticality is identified as an important technical question that receives the majority of attention in the R&D program.

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TYPE Other Report YEAR 2021
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Federal Oversight of Hydrogen Systems

Baird, Austin R.; Ehrhart, Brian D.; Glover, Austin M.; Lafleur, Angela (Chris)

The application of hydrogen as an energy carrier has been expanding into industrial and transportation sectors enabling sustainable energy resources and providing a zero-emission energy infrastructure. The hydrogen supply infrastructure includes processes from production and storage, to transportation and distribution, to end use. Each portion of the hydrogen supply infrastructure is regulated by international, federal, state, and local entities. Regulations are enforced by entities which provide guidance and updates as necessary. While energy sources such as natural gas are currently regulated via the Code of Federal Regulations and United States Code, there might be some ambiguity as to which regulations are applicable to hydrogen and where regulatory gaps may exist. This report contains an overview of the regulations that apply to hydrogen, and those that may indirectly cover hydrogen as an energy carrier participating in a sustainable zero emission global energy system. As part of this effort, the infrastructure of hydrogen systems and regulation enforcement entities are defined, and a visual map and reference table are developed. This regulatory map and table can be used to identify the boundaries of federal oversight for each component of the hydrogen supply value chain which includes production, storage, distribution, and use.

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TYPE SAND Report YEAR 2021
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Thermal-Mechanical Elastic-Plastic and Ductile Failure Model Calibrations for 6061-T651 Aluminum Alloy from Plate

Corona, Edmundo; Kramer, S.L.B.; Lester, Brian T.; Jones, A.R.; Sanborn, Brett; Fietek, Carter J.

Numerical simulations of metallic structures undergoing rapid loading into the plastic range require material models that accurately represent the response. In general, the material response can be seen as having four interrelated parts: the baseline response under slow loading, the effect of strain rate, the conversion of plastic work into heat and the effect of temperature. In essence, the material behaves in a thermal-mechanical manner if the loading is fast enough so when heat is generated by plastic deformation it raises the temperature and therefore influences the mechanical response. In these cases, appropriate models that can capture the aspects listed above are necessary. The matters of interest here are the elastic-plastic response and ductile failure behavior of 6061-T651 aluminum alloy under the conditions described above. The work was accomplished by first designing and conducting a material test program to provide data for the calibration of a modular $J_2$ plasticity model with isotropic hardening as well as a ductile failure model. Both included modules that accounted for temperature and strain rate dependence. The models were coupled with an adiabatic heating module to calculate the temperature rise due to the conversion of plastic work to heat. The test program included uniaxial tension tests conducted at room temperature, 150 and 300 C and at strain rates between 10–4 and 103 1/s as well as four geometries of notched tension specimens and two tests on specimens with shear-dominated deformations. The test data collected allowed the calibration of both the plasticity and the ductile failure models. Most test specimens were extracted from a single piece of plate to maintain consistency. Notched tension tests came from a possibly different plate, but from the same lot. When using the model in structural finite element calculations, element formulations and sizes different from those used to model the test specimens in the calibration are likely to be used. A brief investigation demonstrated that the failure model can be particularly sensitive to the element selection and provided an initial guide to compensate in a specific example.

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TYPE SAND Report YEAR 2021
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Thermal Effects on Gas Pipelines

Brown, Alexander L.

Irradiance from a nuclear weapon can be the source of heat on gas infrastructure. This exposure when sufficiently intense can result in failure. An estimation tool for this behavior is the object of this study. A lumped capacity technique is employed to estimate the system temperature rise. The temperature rise is related to three possible outcomes. Two of the outcomes are relatively certain failure and relatively certain lack of effect. A large range of exposures are assessed with the model, and a relatively small number of cases are in the uncertain range. This model is presented as a tool that can be used in conjunction with a structural assessment model to sensitivities to the overpressure and shock to screen potential outcomes from subject events .

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TYPE SAND Report YEAR 2021
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Vertical GaN Power Electronics - Opportunities and Challenges (invited)

Kaplar, Robert; Allerman, A.A.; Crawford, Mary H.; Gunning, Brendan P.; Flicker, Jack D.; Armstrong, Andrew A.; Yates, Luke; Dickerson, Jeramy; Binder, Andrew; Pickrell, Gregory W.; Sharps, Paul; Neely, Jason C.; Rashkin, Lee J.; Gill, L.; Anderson, T.; Gallagher, J.; Jacobs, A.; Koehler, A.; Tadjer, M.; Hobart, K.; Ebrish, M.; Porter, M.; Martinez, R.; Zeng, K.; Ji, D.; Chowdhury, S.; Aktas, O.; Cooper, James A.

Abstract not provided.

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TYPE Conference Presenation YEAR 2021
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Joint Work Plan for DPC Filler Testing

Rigali, Mark J.

The US generates approximately 2,000 Metric Tons of Heavy Metal (MTHM) of commercial spent fuel (SNF) each year and currently stores ~ 85,000 MTHM of commercial SNF at 70+ reactor sites, the disposal of which is the responsibility of the US Department of Energy (DOE). SNF is initially stored in spent nuclear fueld pools (SFPs). SFPs were initially constructed by US utilities for temporary fuel storage, but with no final disposal pathway available, SFPs are reaching capacity. To allow continued operation of the nation's commercial nuclear reactor fleet, utilities started transferring SNF from SFPs (wet storage) to dry cask storage systems, typically using dual-purpose (storage and transportation) canisters (DPCs). And while DPCs were designed, licensed and loaded to meet Nuclear Regulatory Commission (NRC) requirements that preclude the possibility of a critical event during SNF storage and transport, they were not designed or loaded to preclude the possibility of a criticality event during the regulated post-closure period following disposal, which could be up to 1,000,000 years (Price, 2019). DPC filler option criteria are detailed and materials that exhibit these attributes are explored. This document is an update of the SNL Joint Workplan on Filler Investigations for DPCs.

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TYPE Other Report YEAR 2021
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SCEPTRE 2.2 Quick Start Guide

Drumm, Clifton R.; Pautz, Shawn D.; Bruss, Donald E.; Fan, Wesley C.

This report provides a summary of notes for building and running the Sandia Computational Engine for Particle Transport for Radiation Effects (SCEPTRE) code. SCEPTRE is a general- purpose C++ code for solving the li near Boltzmann transport equation in serial or parallel using unstructured spatial finite elements, multigroup energy treatment, and a variety of angular treatments including discrete ordinates and spherical harmonics. Either the first-order form of the Boltzmann equation or one of the second-order forms may be solved. SCEPTRE requires a small number of open-source Third Part y Libraries (TPL) to be available, and example scripts for building these TPLs are provided. The TPLs needed by SCEPTRE are Trilinos, boost, and netcdf. SCEPTRE uses an autotools build system , and a sample configure script is provided. Running the SCEPTRE code requires that the user provide a spatial finite-elements mesh in Exodus format and a cross section library in a format that will be described. SCEPTRE uses an xml-based input, and several examples will be provided.

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TYPE SAND Report YEAR 2021
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SCEPTRE 2.2 Angular Quadrature Sets

Drumm, Clifton R.; Pautz, Shawn D.; Bruss, Donald E.; Fan, Wesley C.

This document includes details of the angular quadrature sets available in SCEPTRE for performing numerical integrations in the angular phase space. The angular dependence of the boundary and fixed-source terms an d initial angular flux are specified by angular index rather than by direction. It is, therefore, necessary to know the mapping from a specific direction to a direction index. This document includes angular quadrature weights and direction cosines for most of the quadrature sets available in SCEPTRE.

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TYPE SAND Report YEAR 2021
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The ERSDT Software Quality Assurance Plan Practices and Development Environment Setup for RASCAL 5

Whitener, Dustin; Fulton, John

This document includes the information pertaining to the practices of the Emergency Response Software Development Team (ERSDT) for the RASCAL software project. The content includes information regarding: 1) Software Quality Assurance. 2) Project Management. 3) Configuration Management. 4) Development Standards. 5) Third-Party Software. 6) Verification and Validation. The information contained in this report is considered living documentation. The information contained in this report was assembled from multiple documents and content management systems.

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TYPE SAND Report YEAR 2021
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Single Volume Scatter Camera: Optically Segmented Effort

Sweany, Melinda D.; Adamek, E.; Alhajaji, H.; Brown, James R.; Balathy, John; Brubaker, E.; Cabrera-Palmer, B.; Cates, J.C.B.; Dorril, R.; Druetzler, A.; Elam, J.; Febbraro, M.; Feng, Patrick L.; Folsom, Michael W.; Gabella, G.; Galindo-Tellez, A.; Goldblum, B.; Hausladen, P.; Kaneshige, N.; Keffe, Kevin; Laplace, T.A.; Maggi, Paul; Mane, A.; Manfredi, J.; Marleau, P.; Mattingly, J.; Mishra, M.; Moustafa, A.; Nattress, J.; Nishimura, K.; Pinto-Souza, B.; Steele, J.; Takahashi, E.; Ziock, K.

Abstract not provided.

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TYPE Conference Poster YEAR 2021
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Single Volume Scatter Camera: Optically Segmented Effort - Single Slide Overview

Sweany, Melinda D.; Adamek, E.; Alhajaji, H.; Brown, James R.; Balathy, John; Brubaker, E.; Cabrera-Palmer, B.; Cates, J.C.B.; Dorril, R.; Druetzler, A.; Elam, J.; Febbraro, M.; Feng, Patrick L.; Folsom, Michael W.; Gabella, G.; Galindo-Tellez, A.; Goldblum, B.; Hausladen, P.; Kaneshige, N.; Keffe, Kevin; Laplace, T.A.; Maggi, Paul; Mane, A.; Manfredi, J.; Marleau, P.; Mattingly, J.; Mishra, M.; Moustafa, A.; Nattress, J.; Nishimura, K.; Pinto-Souza, B.; Steele, J.; Takahashi, E.; Ziock, K.

Abstract not provided.

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TYPE Conference Poster YEAR 2021
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Results 13001–13200 of 99,299
Results 13001–13200 of 99,299