Thermal-hydrological-mechanical characterization of the Ghareb formation at conditions of high-level nuclear waste disposal.
Abstract not provided.
Kibikas, William↗
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Results for “Mechanical Characterization”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Characterizing Mechanical Behaviors in Varying Relatively Dense AM Lattice Structures Using FEA Modeling
Explore the source record for details and available documents.
Martinez, Elizabeth↗
Mechanical Characterization of Additively Manufactured Inconel 625 via Automated High-Throughput Tensile Testing.
Abstract not provided.
Robbins, Aron↗
In situ mechanical characterization of a single cell-cell adhesion interface under large strain
A method of measuring a stress-strain curve in a cell-cell adhesion interface, the method including: providing a structure including a first movable island supported by a first beam, a second movable island supported by a second beam, and a gap therebetween connected by a pair of cells forming a junction, the pair of cells comprising a cell-cell adhesion interface having an initial length defined by a distance between nuclei of the pair of cells; moving the second movable island with a defined displacement; determining a displacement of the first movable island based on moving the second movable island; calculating a difference between the displacement of the first movable island and the defined displacement of the second movable island based on moving the second movable island; determining an applied strain in the cell-cell adhesion interface between the pair of cells based on the difference divided by the initial length of the cell-cell adhesion interface; calculating a force between the cell-cell adhesion interface of the pair of cells based on the displacement of the first movable island; calculating a stress in the cell-cell adhesion interface between the pair of cells based on the force; and determining the stress-strain curve of the cell-cell adhesion interface between the pair of cells by plotting the calculated stress against the applied strain.
Yang, Ruiguo↗
Characterization of mechanical deformation in aluminum by optical second harmonic generation
Second harmonic generation (SHG), a laser-based surface technique, was used to characterize near-surface defect evolution associated with mechanical deformation in 2024-T3 aluminum due to tensile loads. Electron backscatter diffraction (EBSD) measurements were also performed to determine the geometrically necessary dislocation density before and after tensile deformation. Comparison of the EBSD and SHG results found that dislocation density and SHG signal are inversely proportional; tensile deformation in the plastic regime led to an increase in dislocation density and a decrease in SHG response. A similar trend was seen in the SHG results on as-received (unpolished) Al samples; SHG response decreases with extent of plastic deformation. Furthermore, this study suggests that SHG has potential as a nondestructive evaluation technique.
36 MATERIALS SCIENCE↗
In situ synchrotron X-ray imaging and mechanical properties characterization of additively manufactured high-entropy alloy composites
Laser beam directed energy deposition has become an increasingly popular advanced manufacturing technique for materials discovery as a result of the in situ alloying capability. In this study, we leverage an additive manufacturing enabled high throughput materials discovery approach to explore the composition space of a graded W x (CoCrFeMnNi) 100–x sample spanning 0 ≤ x ≤ 21 at%. In addition to microstructural and mechanical characterization, synchrotron high speed x-ray computer aided tomography was conducted on a W 20 (CoCrFeMnNi) 80 composition to visualize melting dynamics, powder-laser interactions, and remelting effects of previously consolidated material. Results reveal the formation of the Fe 7 W 6 intermetallic phase at W concentrations> 6 at%, despite the high configurational entropy. Unincorporated W particles also occurred at W concentrations> 10 at% accompanied by a dissolution band of Fe 7 W 6 at the W/matrix interface and hardness values greater than 400 HV. In this work, the primary strengthening mechanism is attributed to the reinforcement of the Fe 7 W 6 and W phases as a metal matrix composite. The in situ high speed x-ray imaging during remelting showed that an additional laser pass did not promote further mixing of the Fe 7 W 6 or W phases suggesting that, despite the dissolution of the W into the Fe 7 W 6 phase being thermodynamically favored, it is kinetically limited by the thickness/diffusivity of the intermetallic phase, and the rapid solidification of the laser-based process.
36 MATERIALS SCIENCE↗
Investigating Marine Environmental Degradation of Additive Manufacturing Materials for Renewable Energy Applications: Preprint
Marine renewable energy is a relatively young industry where there is a great need for rapid prototyping in design-build-test campaigns to quickly mature groundbreaking technologies. Additive manufacturing has an important role to play in the industry; however, little information is available to marine energy developers to help inform them on which additive manufacturing materials are appropriate for harsh marine environments. This paper presents an initial study on the mechanical characterization of polymeric additive manufacturing materials and the degradation effects of marine environments. Ultem 9085, acrylonitrile styrene acrylate, and chopped carbon-filled nylon, as well as continuous carbon and glass fiber-reinforced nylon were chosen for this study. Samples were manufactured to perform a variety of tension, shear, and compression mechanical characterization tests on the materials. Half of the samples were conditioned in Pacific Ocean water for approximately 6 months at Pacific Northwest National Laboratory's Marine Sciences Laboratory before being returned for mechanical characterization. The mechanical testing results showed that the Ultem 9085 and acrylonitrile styrene acrylate materials experienced little to no degradation in stiffness or strength after exposure to the marine environment. On the other hand, the nylon-based materials suffered significant stiffness and strength degradation (over 50% in some cases) after environmental conditioning. Ultimately, these data sets should serve as starting points to allow marine renewable energy developers to make informed additive manufacturing material choices for their prototype deployments.
additive manufacturing↗
Investigating Marine Environmental Degradation of Additive Manufacturing Materials for Renewable Energy Applications
Marine renewable energy is a relatively young industry where there is a great need for rapid prototyping in design-build-test campaigns to quickly mature groundbreaking technologies. Additive manufacturing has an important role to play in the industry; however, little information is available to marine energy developers to help inform them on which additive manufacturing materials are appropriate for highly loaded structures in harsh marine environments. This paper presents an initial study on the mechanical characterization of polymeric additive manufacturing materials and the degradation effects due to the marine environment. Ultem 9085, acrylonitrile styrene acrylate, and chopped carbon-filled nylon, as well as continuous carbon and glass fiber-reinforced nylon were chosen for this study. Samples were manufactured to perform a variety of tension, shear, and compression mechanical characterization tests on the materials. Half of the samples were conditioned in Pacific Ocean water for approximately 6 months at the Pacific Northwest National Laboratory's Marine and Coastal Research Laboratory before being returned for mechanical characterization. The mechanical testing results showed that the Ultem 9085 and acrylonitrile styrene acrylate materials experienced little to no degradation in stiffness or strength after exposure to the marine environment. On the other hand, the nylon-based materials suffered significant stiffness and strength degradation (over 50% in some cases) after environmental conditioning. Ultimately, these data sets should serve as starting points to allow marine renewable energy developers to make informed additive manufacturing material choices for their prototype deployments.
additive manufacturing↗
Characterizing the Mechanical Response of the Saturn Accelerator
The Saturn Particle Accelerator is a hot X-ray source used by the NNSA for creating conditions similar to that of a nuclear weapon. When Saturn fires some of it's energy is released in the form of mechanical shock and vibration. This mechanical output has not been characterized or understood, making design of components and diagnostics more difficult. Thus it will be helpful to understand this mechanical shock. This poster presents the beginnings of a project to do just that.
Cuneo, Nicolas Francis [Sandia National Laboratori↗
Anisotropic Characterizations of Electrospun PAN Nanofiber Mats Using Design of Experiments
This paper deals with the dielectric and mechanical characterizations of polyacrylonitrile (PAN)-aligned electrospun nanofiber mats. A two factor three level full factorial experiment is conducted to understand the effect of various parameters on dielectric and mechanical responses. These responses are recorded against randomly oriented and aligned nanofiber mats. Improved properties of electrospun mats have applications in the field of energy storage and nanocomposite reinforcement. Dielectric and mechanical characterizations of PAN mats are vital, as the aligned electrospun mats were found to be useful in advanced energy and mechanical reinforcement applications. Therefore, it is paramount to understand the effects of system parameters to these properties. The design of experiment (DoE) includes two factors and three level full factorial experiments with concentrations of PAN solutions at 8 wt.%, 9 wt.%, and 10 wt.%, and speed of the rotating mandrel (collector) at 3 volt (V), 4 V, and 5 V inputs. The electric field intensity used in the experiment is 1 kV/cm. DoE is conducted to understand the nonlinear interactions of parameters to these responses. The dielectric and mechanical characterizations of 8 wt.%, 9 wt.%, and 10 wt.% with different speeds for the original and improved systems are discussed. It was observed that at 9 wt.% and at all mandrel speeds, the dielectric and tensile properties are optimum.
42 ENGINEERING↗
Investigating Marine Environmental Degradation Of Additive Manufacturing Materials For Renewable Energy Applications
Marine renewable energy is a relatively young industry where there is a great need for rapid prototyping in design-build-test campaigns to quickly mature ground-breaking technologies. Additive manufacturing has an important role to play in the industry; however, little information is available to marine energy developers to help inform them on which additive manufacturing materials are appropriate for harsh marine environments. This paper presents an initial study on the mechanical characterization of polymeric additive manufacturing materials and degradation effects due to the marine environment. Ultem 9085, acrylonitrile styrene acrylate (ASA), and chopped carbon-filled Nylon, as well as continuous carbon and glass fiber reinforced Nylon were chosen for this study. Samples were manufactured to perform a variety of tension, shear, and compression mechanical characterization tests on the materials. Half of the samples were conditioned in Pacific Ocean water for approximately 6 months at the Pacific Northwest National Laboratory’s Marine and Coastal Research Laboratory before being returned for mechanical characterization. The mechanical testing results showed that the Ultem 9085 and ASA materials experienced little to no degradation in stiffness or strength after exposure to the marine environment. On the other hand, the Nylon-based materials suffered significant stiffness and strength degradation (over 50% in some cases) after environmental conditioning. Ultimately, these results should serve as starting points to allow marine renewable energy developers to make informed additive manufacturing material choices for their prototype deployments.
Murdy, Paul↗
Characterization of Mechanical Ventilation Systems in New US Homes: What types of systems are out there and are they functioning as intended?
As the airtightness of homes improves to meet energy efficiency goals, it becomes more important for mechanical ventilation systems to help maintain a comfortable and healthy indoor air environment. ASHRAE Standard 62.2 provides national guidance for mechanical ventilation system design and installation, however adoption of those guidelines into local building codes has occurred at different rates. Once provisions for mechanical ventilation are adopted in a local code, are mechanical ventilation systems properly designed, installed, commissioned and operated according to code or above code program requirements? Is there a need for further industry and homeowner education to ensure systems function as intended? This paper presents results from field studies that include characterization of mechanical ventilation systems in over 150 new homes in CA, CO, FL, GA, IL, OR, and SC built between 2011 and 2018. In each of the study homes, airflow of local (kitchen, bathrooms) and whole-house ventilation were measured. Occupant usage of the mechanical ventilation systems were monitored for one week in each home. Installed performance is compared to inferred design intent. The paper also includes homeowner perceptions about, and interactions with, the installed mechanical ventilation systems.
Martin, Eric↗
Polymer Additive Manufacturing for Marine Renewable Energy Applications: Best Practices, Research Trends, and Current Challenges
Additive manufacturing (AM) is a rapidly growing technology space, not only for prototyping, but is also becoming more feasible at larger scales and increasing component quantities. There are a large variety of AM processes and materials available to users and effectively applying those processes and materials to a specific use case can be challenging. One specific area where AM could be particularly beneficial is marine renewable energy (MRE). Not only is MRE a relatively nascent industry with a near-term need for rapid deployments and prototype testing, but developers could also see long-term benefits from the broad variety of environmentally resistant materials available and the ability to manufacture complex geometries that AM technologies offer. Over the past 4 years, AM materials have played an increasing role in the Advanced Materials project; a multi-year, multi-laboratory research project funded by the U.S. Department of Energy's Water Power Technologies Office, with the main goal of reducing barriers to the adoption of complex materials in the MRE industry. The primary focus of this project is to develop test methods and generate datasets to understand the long-term performance of advanced materials in marine environmental and address specific material challenges as they arise. This report provides an extensive overview of the research that has been performed specific to AM polymers as part of the Advanced Materials project. The intention of this document is to provide recommendations of best practices with regards to material selection, mechanical test method development, and design practices, lessons learned along the way, current research trends, and ongoing challenges with regards to AM polymers in marine environments. In particular, this report focuses on several key aspects: Material and process selection, Environmental conditioning and subsequent degradation quantification through mechanical characterization, Composite reinforcements on AM polymer substrates, Adhesion of instrumentation for mechanical characterization and loads measurements, Protective coatings for preventing biofouling and water ingress, Other MRE case studies where AM has proved particularly useful. Ultimately, we hope that the test methods that have been developed, data generated, and lessons learned from this research will be valuable to the MRE community (researchers and developers alike), as well as other industries, and can be used as a reference point as the respective MRE and AM industries continue to grow and mature.
16 TIDAL AND WAVE POWER↗
Characterization of mechanical discontinuities based on data-driven classification of compressional-wave travel times
Wave propagation and diffusive transport phenomena are influenced by the mechanical discontinuities in material. Here this study shows that certain bulk properties of the network of low-velocity mechanical discontinuities (e.g. air-filled cracks) in a material can be characterized by processing compressional-wave travel times using traditional data-driven classification techniques. To that end, we perform three tasks in chronological order: (1) use the discrete fracture network (DFN) method to create two-dimensional (2D) numerical models of crack-bearing material embedded with various types of low-velocity mechanical discontinuities, (2) use the fast marching method (FMM) to simulate the propagation of the wave/diffusion front from a single source through the 2D crack-bearing material to multiple receivers placed on the boundary of the material, and (3) train 9 data-driven classifiers to characterize the crack-bearing materials (i.e. bulk properties of the network of mechanical discontinuities in the crack-bearing material) by learning from the simulations of travel times detected by multiple receivers placed around the crack-bearing material. The classifiers identified the orientation, spatial distribution, and dispersion of the low-velocity mechanical discontinuities. Voting classifier performs the best among the 9 classifiers. For the characterization of bulk dispersion and distribution of discontinuities, the sensors located on the adjacent boundaries are more important; whereas for the characterization of bulk orientation of discontinuities, the sensors located on the opposite side are more important.
42 ENGINEERING↗
Full circle mechanical dynamic characterization including experimental modal analysis and finite element analysis
During operation, it was observed that a specific mechanical system experienced undesirable vibration and it became necessary to understand and mitigate this phenomenon. This document investigates the tools, methodology, and results of the dynamic characterization of the system. The characterization makes use of the experimental modal analysis (EMA) methods of single input multiple output (SIMO) and single input single output (SISO). The validity of the theory of reciprocity is confirmed to minimize measurement error, cost, and time of repeat testing. Finite element analysis (FEA) is used in choosing transducer and modal impact locations to adequately characterize the system. Single degree of freedom (SDOF) and multiple degree of freedom (MDOF) curve fitting is used to fully characterize the system’s mode shapes and natural frequencies. The EMA characterization results are used to modify and validate the FEA model so that FEA can be used to model potential structural modifications to the system to mitigate the undesirable vibration. Structural modifications are chosen, implemented, and their effectiveness is quantified using EMA. Finally, a qualitative evaluation of the methodology of FEA validation by EMA and tuning of the model to match the experimental results is discussed.
42 ENGINEERING↗
Interparticle Characterization of Mechanical Biomass Particle-Particle and Particle-Wall Interactions
The biomass materials industry faces significant challenges in managing material variability and its impact on storage and handling systems. Physical properties such as moisture content, particle size, and density fluctuate considerably, leading to operational issues like bridging and ratholing that disrupt material flow. These variations create a complex cascade effect throughout the process chain, affecting transportation, storage, and conversion processes. The economic consequences of this variability manifest in increased operational costs, maintenance requirements, and system downtime. Environmental factors further complicate the situation, as weather conditions and seasonal availability influence material properties and system performance. Engineers employ specialized equipment design, material characterization protocols, and pre-processing steps like size reduction and homogenization to address these challenges. A critical knowledge gap exists between continuous-level constitutive models and particle-scale behavior. This project developed a novel device to quantify interparticle mechanics between biomass particles, measuring friction and adhesion forces between particles and wall materials. The research focused on corn stover and southern pine forest residue, creating a comprehensive database of particle interactions. This breakthrough enables direct application in particle-based computational modeling, advancing the field's understanding of biomass handling characteristics and supporting the development of more reliable and efficient storage and handling systems. The project's outcomes contribute significantly to understanding biomass's mechanical and flow characteristics, particularly how variability at the particle level affects larger-scale handling operations. This knowledge is crucial for engineering feedstock supply systems that consistently meet quality and cost specifications for various conversion processes. The innovative experimental setup developed through this research represents a significant advancement in biomass characterization methodology. Providing precise measurements of particle-level interactions establishes a foundation for more accurate predictive modeling of bulk material behavior. This enhanced understanding of fundamental particle mechanics enables engineers to anticipate better and address handling challenges before they manifest in full-scale operations. This research opens new avenues for optimizing biomass handling systems through data-driven design approaches. The comprehensive database of particle interactions serves as a valuable resource for future research and development efforts, potentially leading to more efficient and cost-effective biomass processing solutions. This advancement in particle-level mechanics could revolutionize how biomass handling systems are designed and operated, contributing to more sustainable and reliable renewable energy production.
09 BIOMASS FUELS↗
Characterization of mechanical properties and deformation behavior of highly irradiated 316L stainless steel from target modules at the Spallation Neutron Source using digital image correlation analysis
Tensile specimens with irradiation doses ranging from approximately 0.7 to 7.6 displacements per atom (dpa) were fabricated from 316L samples removed from Spallation Neutron Source (SNS) target vessels after service. Tensile tests were performed in conjunction with digital image correlation (DIC) characterization, which permitted detailed analysis of the strain distribution and deformation behavior of the specimen gauge sections during testing. The results show, while considerable hardening (500–700 MPa increase in yield strength) occurred in the 316L SNS target material with increasing dose, appreciable ductility (19–23% total elongation) remained in the material after irradiation to 7.6 dpa in the mixed neutron/proton environment of the SNS target region. The DIC data showed the strain distribution and deformation behavior of all irradiated specimens were nonuniform during testing. Strain localization in the form of deformation bands or “hotspots” was observed during testing, and in some specimens, the bands propagated as deformation waves along the gauge section. The “traveling wave” deformation behavior affected the amount of elongation each specimen achieved, and the scatter in the elongation data was attributed to the large variation in deformation behavior observed among different specimens. Bands of localized strain, or deformation bands, oriented at specific angles were observed in two-dimensional plots of the strain distribution in the gauge sections of some specimens. Overall, this paper describes the experimental procedures, results, and deformation behavior of tensile specimens from SNS targets after service and illustrates the value of DIC characterization during tensile testing of irradiated materials.
36 MATERIALS SCIENCE↗
Characterizing The Mechanical Properties of Polyurethane Foams
The Department of Energy has many radioactive facilities that are on the path of deactivation and decommissioning (D and D). These facilities can sit cold and dark for many years before final disposition, and must be maintained to ensure no radiological release occurs in the interim. Improvements and additions to D and D tool sets can greatly: Save time and money, Reduce worker risk. Conventional fixatives widely used often take the form of paints or films that are not readily applicable to 3-dimensional void spaces. Foams are one promising platform that may offer solutions to a number of contaminated problem sets such as: Gloveboxes, Pipes, Tanks. SRNL is working to characterize various commercial foams that would encapsulate the interior volume of a given space and are capable of immobilizing any remaining contamination. One key performance metric of these foams is how well they will perform in an accident scenario. To this end, SRNL is researching the mechanical properties of these foams to ensure that the material can withstand the environment of application while maintaining structural integrity. ASTM standard E3191-18 served as a guiding document for this project, outlining the requirements that foaming fixatives used for the mitigation of radioactive contamination need to meet before being implemented. Objective: Quantification of the mechanical properties of 6 commercial polyurethane foams was performed using multiple ASTM standards to record measurements for: Compression testing: Flexible Foams, Force required to produce 50% compression, Rigid Foams, Compressive and apparent modulus, Point of 10% core deformation, The 'Zero Deformation' point, Compressive strength, Yield point. Tensile testing: Tensile strength, Tensile stress, Percent elongation. Experiment 1: An electromechanical compressive tester (MTS Criterion Series 43) was used to evaluate 6 foams (4 flexible, 2 rigid). Per ASTM D1621, each rigid foam was compressed at 10% of the measured thickness per minute until the sample was 13% of it's original thickness. Per ASTM D35/4, each flexible foam was pre-flexed twice to 80% original thickness at a rate of 250 mm/min, then compressed to 80% original thickness at a rate of 50 mm/min. Experiment 2: An electromechanical tensile tester (MTS Criterion Series 43) was used to evaluate 6 foams (4 flexible, 2 rigid). Per ASTM D1623, rigid foams were pulled apart at a rate of 1.27 mm/min until the sample broke. Per ASTM D35/4, flexible foams were pulled apart at a rate of 500 mm/min until the sample broke. The strongest material in both compression and tensile testing scenarios was found to be the rigid intumescent polyurethane Hilti foam. The experiments revealed that the Hilti foam in a tensile scenario had a peak stress value that was larger than the closest competitor by a factor of 2.3 and a compressive yield point that was larger than the closest competitor by a factor of 1.4, indicating that the Hilti foam is the best choice for implementation in mechanically harsh environments. The performance metrics measured can serve as a basis for future mechanical tests that would help set relevant ASTM standards (E3191) for intumescent polyurethane foams in fixating applications. Tests like surface adhesion, impact, and flame tests would serve as a better indicator as to how this material would perform in environmentally harsh scenarios often found in decommissioned nuclear facilities. Further tests of the foams' intumescent properties would also be important should these foams be implemented in environmentally harsh scenarios.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗