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Results for “Youngs Modulus”

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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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Investigation of the influence of geomechanical and hydrogeological properties on surface uplift at In Salah [Systematic investigation of the influence of geomechanical and hydrogeological properties on surface uplift at In Salah]

Coupled reservoir and geomechanical simulations are significantly important to understand the long-term behavior of geologic carbon storage (GCS) systems. In this study, we performed coupled fluid flow and geomechanical modeling of CO 2 storage using available field data to (1) validate our existing numerical model and (2) perform parameter estimation via inverse modeling to identify the impact of key geomechanical (Young's modulus and Biot's coefficient) and hydrogeological (permeability and anisotropy ratio) properties on surface uplift and the pore pressure buildup at In Salah in Algeria. Furthermore, two sets of surface uplift data featuring low and high uplifts above two injection wells and the maximum change in the pore pressure due to CO 2 injection were used to constrain the inverse model.

58 GEOSCIENCES↗
DOE OSTI2021

Stress-sensitivity of fracture conductivity of Tuscaloosa Marine Shale cores

Production decline from wells producing from shale rocks is typically quite rapid. One possible factor responsible for such decline is loss in fracture conductivity. This is true in the case of the Tuscaloosa Marine shale reservoir. In this work, the stress-dependent fracture conductivity of TMS core samples is investigated using five propped cores under varying stress conditions. In addition, the effects of static rock mechanical properties and rock mineralogy on conductivity decline are investigated. The mineralogy of each core sample was determined by X-ray Diffraction analysis. Fracture conductivity was measured using a Hassler-type pressure core holder with a pressure rating of 15,000 psi (103.42 MPa). Estimated rock mechanical properties showed that shale anisotropy could affect fracture conductivity. The time decline in conductivity revealed two possible decline trends, a) decline from the reduction in induced fracture width, and b) decline from the healing of developed micro-cracks. An exponential decline in fracture conductivity with increasing confinement pressure was observed with an average decline rate constant of 3.15 x 10 -10 mPa -1 . While rock mineralogy did not have any clear relationship with conductivity decline, the effects of rock mechanical properties were only important at 10.34 MPa confinement pressure and above. The observation showed that a high Young's modulus correlate to high conductivity, whereas a high Poisson's ratio correlate to low conductivity. This study provides useful observations for optimizing fracture design to enhance well productivity in the TMS.

02 PETROLEUM↗
DOE OSTI2019

Stability and superconductivity of TiPH n (n = 1–8) under high pressure

Titanium exhibits high affinity to hydrogen and the Ti-H compounds are thermodynamically stable. We introduced the Ti elements in the P-H compounds to deal with the thermodynamic-instability issue of the P-H compounds. In this work, ternary hydrogen-rich compounds TiPH n (n = 1-8) were studied and calculated using the density function theory (DFT) method. The results showed that the TiPH 4 and TiPH 8 had high superconducting critical temperatures (T c ) as well as better stability. Further, among TiPH n (n = 1-8), the TiPH and TiPH 4 were most stable at 50-200 and 250-300 GPa, respectively. For the R-3m-TiPH 4 structure, the predicted T c 's are 52 and 62 K at 100 and 250 GPa, respectively, and its larger Young's modulus suggested that it might be potentially synthetized in experiment.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Synthesis and thermomechanical characteristics of zwitterionic poly(arylene ether sulfone) copolymers

Charge-containing polymeric materials have been widely studied for a range of applications. The fundamental relationships between the charge species, charge density, and the microscale morphology of charge-containing polymers are critical for defining the application in which they may be used. In this work, a series of thermoplastic poly(arylene ether sulfone) (PAES) copolymers with controllable sulfobetaine charge contents (0~100 mol%) and high molecular weights (Mw ~ 65 kDa) were prepared. All the zwitterionic PAESs synthesized showed thermal stability up to 250 °C. DSC and tensile tests showed a decreased T g and mechanical strength with the incorporation of increasing charge density, which suggests a plasticization effect by the charged group. Electron microscopy and X-ray scattering data confirmed the absence of microphase separation in the ion-containing random copolymer system, which corroborated with the observation of a single T g for all zwitterionic copolymers studied. Furthermore, the relative hydrophilicity of the samples was evaluated by water uptake measurements, which revealed that the water uptake of the zwitterionic PAESs can reach up to 64% for the 72 mol% zwitterion copolymer while the free-standing film in the wet state still maintains a Young's modulus of 185 MPa. Here, the thermoplastic charge-containing copolymers in this work demonstrated potential for applications such as coatings or water purification membranes, in which balancing hydrophilicity, processibility, and thermomechanical performance are important.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

3D printing of a recycled copolyester of terephthalic acid, cyclohexanedimethanol and tetramethylcyclobutanediol

2,2,4,4-Tetramethyl-1,3-cyclobutanediol (TMCD) is a diol monomer for terephthalic acid (TPA) class of copolyesters that can increase the glass transition temperature and mechanical strength in comparison to conventional TPA polyesters. TMCD-modified poly (1,4-cyclohexylenedimethylene terephthalate) (PCTT) has been used to manufacture consumer products with good toughness, heat resistance and clarity. However, the suitability of PCTT in 3D printing had not been evaluated. Therefore, consumer plasticware was used as the starting material to investigate the suitability of this copolyester for fused deposition modeling (FDM). Here, chemical structure, mechanical properties, thermal behavior and viscoelastic properties of this copolyester were studied. NMR spectroscopy found that the copolyester had cyclohexanedimethanol (CHDM) and TMCD contents at 76.5 mol% and 20 mol% of total diol, respectively. 280 °C printing temperature and 110 °C bed temperature were suitable conditions for printing. T g of PCTT was 103 °C (25 °C higher than PETG). Young's modulus and impact strength of printed PCTT were at least 100% and 65% higher than printed PETG, respectively. The ease of printing, superior mechanical properties and T g (103 °C) make the PCTT random copolyester highly applicable in additive manufacturing.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Calibration of linear contact stiffnesses in discrete element models using a hybrid analytical-computational framework

Efficient selections of particle-scale contact parameters in discrete element modelling remain an open question. The purpose of this study is to provide a hybrid calibration framework to estimate linear contact stiffnesses (normal and tangential) for both two-dimensional and three-dimensional simulations. Analytical formulas linking macroscopic parameters (Young's modulus, Poisson's ratio) to mesoscopic particle parameters for granular systems are derived based on statistically isotropic packings under small-strain isotropic stress conditions. By taking the derived analytical solutions as initial approximations, the gradient descent algorithm automatically obtains a reliable numerical estimation. The introduced framework is validated with several numerical cases including randomly distributed monodisperse and polydisperse packings. The results show that this hybrid method practically reduces the time for artificial trials and errors to obtain reasonable stiffness parameters. The proposed framework can also be extended to other parameter calibration problems in DEM.

Calibration method↗
DOE OSTI2022

Reverse scaling of a bonded-sphere DEM model: Formulation and application to lignocellulosic biomass microstructures

We explore scaling laws for adapting a bonded-sphere discrete element method (BS-DEM) model developed for woody structural mechanics at the millimeter scale to model the mechanics of realistic lignocellulosic biomass microstructures. Two scaling approaches, i.e., the reverse coarse graining (RCG) and equivalent bulk behavior (EBB), are proposed based on the classical mechanics principles and assessed in the single-particle compression and rectangular cuboid block tension tests. The EBB approach is recommended for BS-DEM models with general 3D geometries and is applied to simulate the microindentation test on a realistic microscale pinewood specimen. Simulations are performed to elucidate the impact of specimen thickness and loading position on the specimen’s force–deformation behavior. Furthermore, the range of Young’s modulus obtained from the calibrated BS-DEM simulations can match the experimental measurements. This is the first-of-its-kind study that has explored scale-bridging modeling approaches in biomass micromechanics and has proposed solutions based on BS-DEM models in the microscale.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Quantification of irradiation defects in beta-silicon carbide using Raman spectroscopy

Raman spectra from polycrystalline beta-silicon carbide (SiC) were collected following neutron irradiation at 380–1180 °C to 0.011–1.87 displacement per atom. The longitudinal optical (LO) peak shifted to a lower frequency and broadened as a result of the irradiation. The changes observed in the LO phonon line shape and position in neutron-irradiated SiC are explained by a combination of changes in the lattice constant and Young's modulus, and the phonon confinement effect. The phonon confinement model reasonably estimates the defect-defect distance in the irradiated SiC, which is consistent with results from previous experimental studies and simulations.

36 MATERIALS SCIENCE↗
DOE OSTI2018

In-situ synchrotron X-ray diffraction study of dual-step strain variation in laser shock peened metallic glasses

Atomic-structure evolution is significant in understanding the deformation mechanism of metallic glasses. Here, we firstly find a dual-step atomic strain variation in laser-shock-peened (LSPed) metallic glasses during compression tests by using in-situ synchrotron X-ray diffraction. Under low compressive load, LSP-deformed zone’s atomic-structure shows low Young’s Modulus (E); with load increase, atomic-structure are re-hardened, showing high E. An atomic deformation mechanism is proposed by using flow unit model, that LSP could induce interconnected flow units and 2 homogenize the atomic-structure. Furthermore, these interconnected flow units are metastable and start to annihilate during compressive loading, causing the dual-step atomic strain variation.

36 MATERIALS SCIENCE↗
DOE OSTI2022

The mechanical behavior of metal-halide perovskites: Elasticity, plasticity, fracture, and creep

Wide ranging mechanical properties — elasticity, plasticity, fracture, and creep — most relevant to the mechanical reliability of perovskite solar cells (PSCs) are systematically investigated. High quality bulk single-crystals of the commonly studied metal-halide perovskites (MHPs) relevant to PSCs are fabricated and studied: CH 3 NH 3 PbBr 3 (MAPbBr 3 ) and CH 3 NH 3 PbI 3 (MAPbI 3 ). The first direct measurement of MHP Young's modulus (E) using uniaxial compression reveals E <100> of 13.1 ± 1.3 and 10.6 ± 1.0 GPa for MAPbBr 3 and MAPbI 3 , respectively. Further, the Vickers micro-hardness H (100) of MAPbBr 3 and MAPbI 3 is 0.54±0.02 GPa and 0.76±0.05 GPa, respectively. The Vickers micro-indentation fracture toughness K IC of MAPbBr 3 and MAPbI 3 is estimated at 0.20±0.03 MPa∙m 0.5 and 0.18±0.03 MPa∙m 0.5 , respectively. The stress-exponent, n, extracted from nanoindentation creep data is ~8 and ~10 for MAPbBr 3 and MAPbI 3 , respectively. The trends in these properties are discussed. These properties are best estimates and are recommended for use in future mechanical behavior and reliability analyses of MHPs and PSCs.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Effect of docetaxel on mechanical properties of ovarian cancer cells

Docetaxel could inhibit the proliferation of tumor cells by targeting microtubules. The extension of cellular microtubules plays an important role in the invasion and metastasis of tumor cells. This paper aims to study the distribution and mechanical properties of cytoskeletal proteins with low concentration of docetaxel. MTT assay was used to detect the minimum drug activity concentration of docetaxel on SKOV-3 cells, fluorescence staining was used to analyze the distribution of cytoskeleton proteins, scanning electron microscopy(SEM) was used to observe the morphology of single cells, and atomic force microscopy(AFM) was used to determine the microstructure and mechanical properties of cells. The results showed that the IC{sub 10} of docetaxel was 1 ng/ml. Docetaxel can effectively inhibit the formation of cell pseudopodia, hinder the indirectness between cells, reduce the cell extension area, and make the cells malformed. In addition, when AFM analyzes the effects of drugs on cell microstructure and mechanical properties, the average cell surface roughness and cell height are positively correlated with the concentration of docetaxel. Especially when the concentration was 100 ng/ml, the adhesion decreased by 37.04% and Young's modulus increased by 1.57 times compared with the control group. This may be because docetaxel leads to microtubule remodeling and membrane protein aggregation, which affects cell microstructure and increases cell strength, leading to significant changes in the mechanical properties of ovarian cells. This is of great significance to the study of the formation mechanism of tumor cell invasion and migration activities mediated by actin.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Computational and Experimental Determination of the Properties, Structure, and Stability of Peptoid Nanosheets and Nanotubes

Peptoids (N-substituted glycines) are a group of highly controllable peptidomimetic polymers. Amphiphilic diblock peptoids have been engineered to assemble crystalline nanospheres, nanofibrils, nanosheets, and nanotubes with biochemical, biomedical, and bioengineering applications. The mechanical properties of peptoid nanoaggregates and their relationship to the emergent self-assembled morphologies have been relatively unexplored and are critical for the rational design of peptoid nanomaterials. In this work, we consider a family of amphiphilic diblock peptoids consisting of a prototypical tube-former (Nbrpm6Nc6, a NH 2 -capped hydrophobic block of six N-((4-bromophenyl)methyl)glycine residues conjugated to a polar NH 3 (CH 2 ) 5 CO tail), a prototypical sheet-former (Nbrpe6Nc6, where the hydrophobic block comprises six N-((4-bromophenyl)ethyl)glycine residues), and an intermediate sequence that forms mixed structures ((NbrpeNbrpm)3Nc6). We combine all-atom molecular dynamics simulations and atomic force microscopy to determine the mechanical properties of the self-assembled 2D crystalline nanosheets and relate these properties to the observed self-assembled morphologies. We find good agreement between our computational predictions and experimental measurements of Young’s modulus of crystalline nanosheets. A computational analysis of the bending modulus along the two axes of the planar crystalline nanosheets reveals bending to be more favorable along the axis in which the peptoids stack by interdigitation of the side chains compared to that in which they form columnar crystals with π-stacked side chains. Here, we construct molecular models of nanotubes of the Nbrpm6Nc6 tube-forming peptoid and predict a stability optimum in good agreement with experimental measurements. A theoretical model of nanotube stability suggests that this optimum is a free energy minimum corresponding to a “Goldilocks” tube radius at which capillary wave fluctuations in the tube wall are minimized.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Structural Comparison of Various Silkworm Silks: An Insight into the Structure–Property Relationship

Silkworm silk has attracted considerable attention in recent years due to its excellent mechanical properties, biocompatibility, and promising applications in biomedical sector. However, a clear understanding of the molecular structure and the relationship between the excellent mechanical properties and the silk protein sequences are still lacking. This study carries out a thorough comparative structural analysis of silk fibers of four silkworm species (Bombyx mori, Antheraea pernyi, Samia cynthia ricini, and Antheraea assamensis). A combination of characterization techniques including scanning electron microscopy, mechanical test, synchrotron X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and NMR spectroscopy was applied to investigate the morphologies, mechanical properties, amino acid compositions, nanoscale organizations, and molecular structures of various silkworm silks. Furthermore, the structure–property relationship is discussed by correlating the molecular structural features of silks with their mechanical properties. Here, the results show that a high content of β-sheet structures and a high crystallinity would result in a high Young’s modulus for silkworm silk fibers. Additionally, a low content of β-sheet structures would result in a high extensibility.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

Interfacial Phenomena and Mechanical Behavior of Polyetheretherketone/Polybenzimidazole Blend under Hygrothermal Environment

Demands for engineering applications of high performance polymers, such as the polyaryletherketone families, have grown significantly in recent years. Fundamental knowledge on the mechanical behavior of such polymers, especially under harsh environments, is still lacking. In this study, the mechanical behavior and interfacial phenomena of a blend of polybenzimidazole (PBI) particles having sizes of about 50 μm and polyetheretherketone (PEEK) matrix at 50:50 weight ratio was characterized. PBI and PEEK are known to be incompatible with each other in the dry state. The possible influence of hygrothermal exposure on interfacial bonding between PEEK and PBI has been systematically studied. Under dry conditions, the PEEK matrix dominates the dynamic mechanical behavior, indicating no noticeable viscoelastic coupling between the two phases. After being exposed to hygrothermal conditions, the T g of the PEEK phase in the blend shifts to a lower temperature by as much as 26 °C. The extent of this shift is much greater than what is observed for neat PEEK alone under the same condition. Nanomechanical property mapping results indicate that the interfacial region is broadened after 288 °C hot water immersion treatment. The above finding strongly suggests the hygrothermal conditioning promotes apparent compatibility between PEEK and PBI. Likewise, the fracture behavior of the blend provides direct evidence that the interfacial adhesion is greater than the cohesive strength of either phase after water immersion. In the meantime, it is found that both fracture toughness and tensile strength of the blend are improved by water absorption at 60 °C, at the expense of a minor reduction in Young’s modulus. However, if the blend is exposed to hot water at 288 °C, all of the mechanical properties will deteriorate significantly. In conclusion, the possible causes of the mechanical property deterioration in the PEEK/PBI blend after hygrothermal treatment are discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Sulfurized Polyacrylonitrile (SPAN): Changes in Mechanical Properties during Electrochemical Lithiation

Sulfurized polyacrylonitrile (SPAN) is a promising material for stable lithium-sulfur (Li-S) batteries that can potentially satisfy the demand for high-density energy storage devices for electric vehicles (EVs). However, important physical and chemical properties of the SPAN cathode material are not yet well understood. For example, the SPAN mechanical behavior that depends on the structure and chemistry of the material generated during synthesis, and the mechanical response evolution during battery discharge have been scarcely investigated. This work addresses the effects of electrochemical lithiation on the SPAN mechanical integrity via uniaxial tensile loading tests using molecular dynamics with the ReaxFF potential. Here, we evaluate the volume expansion, Young’s modulus, yield strength, and ultimate tensile strength with increasing lithium contents. Our results show how the degree of graphitization of the carbonized skeleton impacts the SPAN ability to withstand the volume expansion-induced structural stresses upon lithiation. We describe the fracture mechanisms and find out a ductility loss with increasing lithium contents

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Stabilization of Preternatural Barium Oxidation States as an Unexpected Byproduct of β-Decay: Discovery of a New Halide Semiconductor Alloy

137 Cs has a wide range of roles in the nuclear industry. The solid material, safely encapsulated in CsCl as 137 CsCl, is stored as fission product waste from nuclear power production and legacy waste from nuclear weapons production; it has also served as a radiation source in food and sewage irradiators as well as medical devices. However, because of the solubility of the chloride salt and the relatively high specific activity of 137 Cs, damaged or broken capsules can lead to severe radiological accidents. Safe capsule design and material recycling are complicated by the unclear structural evolution during β-decay, which remains ambiguous due to the differing oxidation states of Cs (1+) and Ba (2+). Here, in this study, we use first-principles calculations to investigate the evolving structure–property relationships of Cs 1–x Ba x Cl during β-decay. Despite the well-established 2+ formal oxidation state of alkali-earth metals, we find that Ba 1+ can be stabilized in the form of a mixed-valence alloy at low concentrations. Specifically, we identify three regimes for the β-decay of 137 Cs into CsCl: Ba-doped CsCl (Ba ≤ 14%), wherein Ba has the expected 2+ oxidation state; Cs–Ba–Cl alloys, where Ba has a mix of the usual Ba 2+ and highly unusual Ba 1+ oxidation state in the form of a quasi-disordered mixed-valence alloy (Ba = 25%); and phase separation into a CsCl + BaCl 2 + Ba (m) mechanical mixture, where Ba reverts to its expected 2+ oxidation state (Ba > 25%). Surprisingly, the Cs 0.75 Ba 0.25 Cl mixed-valence alloy is a narrow indirect band gap semiconductor (1.05 eV) despite the insulating nature of both CsCl and BaCl 2 . It also exhibits strongly excitonic polarized optical properties, has glass-like ultralow thermal conductivity (directional average of 0.21 W/mK at 300 K), and shows greater resistance to deformation under both tensile and volumetric strengths compared with the original CsCl structure (e.g., shear and Young’s modulus of 9.04 and 31.62 GPa, respectively). These findings imply that transmutation of 137 Cs leads to highly unusual chemical bonding that stabilizes Ba 1+ in local regions of the quasi-disordered Cs 0.25 Ba 0.75 Cl, resulting in anomalous physical properties. Moreover, this discovery provides valuable insight for safe nuclear waste capsule design, which can aid in preventing environmental or human exposure to radioactive materials.

Fuhr, Addis S. [Oak Ridge National Laboratory (ORN↗
DOE OSTI2017

Atomic-Scale Quantification of Interfacial Binding between Peptides and Inorganic Crystals: The Case of Calcium Carbonate Binding Peptide on Aragonite

Using a specific explicitly solvated interface model between a calcium carbonate binding peptide and crystalline aragonite, we investigate the electronic structure, atomic bonding, solvation effect, and the role of hydrogen bonding on the cohesion, stability, and functionality of this complex hybrid system using density functional calculation. The large interface model is strategically constructed using a stepwise procedure followed by ab initio molecular dynamics to obtain the optimal conformation. The calculated data on the electronic structure and bonding are analyzed in terms of three structural parts: aragonite, peptide, and water. Next, we focus on the binding between aragonite (001) surface and the peptide mediated by water. Finally, specific interatomic bonding between the amino acids in peptide and the (001) surface of aragonite is quantified. A single quantum mechanical metric, the total bond order density (TBOD), infers the dynamic interplay of different competing interactions. Four amino acids HIS1, ARG6, MET7, and TRP11 in the peptide sequence have strong interfacial Ca–O bonding and O···H hydrogen bonding between aragonite and peptide. The calculated Young’s modulus 33.37 GPa is in line with the measured value for nacre. Our approach for interfacial study between aragonite and a calcium carbonate binding peptide offers a broad perspective for probing complex interactions between the biomimetic interfaces. Finally, TBOD can be used as an effective parameter in ranking the efficacy of peptide–surface interactions and in providing a programmable design for bio-inspired material interfaces based on computational means.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Synthesis of Poly(ionic Liquid)s-block-poly(methyl Methacrylate) Copolymer-Grafted Silica Particle Brushes with Enhanced CO 2 Permeability and Mechanical Performance

Poly(ionic liquid) (PIL)-based block copolymers are of particular interest as they combine the specific properties of PILs with the self-assembling behaviors of block copolymers, broadening the range of potential applications for PIL-based materials. In this work, three particle brushes: SiO 2 -g-poly(methyl methacrylate) (PMMA), SiO 2 -g-PIL, and SiO 2 -g-PMMA-b-PIL were prepared through surface-initiated atom transfer radical polymerization. Unlike the homogeneous homopolymer particle brushes, the block copolymer particle brush SiO 2 -g-PMMA-b-PIL exhibited a bimodal chain architecture and unique phase-separated morphology, which were confirmed by size-exclusion chromatography and transmission electron microscopy. In addition, the influence of the introduction of the PMMA segment on the gas separation and mechanical performance of the PIL-containing block copolymer particle brushes were investigated. A significant improvement of Young’s modulus was observed in the SiO 2 -g-PMMA-b-PIL compared to the SiO 2 -g-PIL bulk films; meanwhile, their gas separation performances (CO 2 permeability and CO 2 /N 2 selectivity) were the same, which demonstrates the possibility of improving the mechanical properties of PIL-based particle brushes without compromising their gas separation performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗