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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Husseini, Jamal F. Stapleton, Scott E. Carey, Eric J. Pineda, Evan J. Mechanical Engineering University of Massachusetts Lowell LowellMA01854 United States Multiscale and Multiphysics Modeling NASA Glenn Research Center ClevelandOH44135 United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

Fiber reinforced composites are desirable in applications where low weight and high strength are needed, but are susceptible to microscale variability during manufacturing, making failure predictions difficult. The impact microscale variability has on macroscale mechanical response is difficult to predict due to the computational efficiency needed to simulate many, large, high fidelity, microscale models. In this study, a multiscale approach was taken to model 3-point bend, 4-point bend, and tensile experiments of a unidirectional composite from only having microstructure scans of these samples and constituent properties from literature. These scans were sampled with different sized windows, and statistically equivalent microstructures were generated, then simulated for stiffness, strength, and fracture toughness using an efficient micromechanical. Mesoscale models were created where element sizes equaled microstructure size, and properties were assigned through sampling of microscale simulation results. First, this study showed the effect of using Weibull scaling on constituent matrix strength on macroscale response. Then, a comparison was made between different element sizes and experiments. Finally, model dimensions were fixed, and the effect of randomly distributed local properties alone was examined. Results showed that the scatter of strength and stiffness in the experiments could be predicted well using images of the microscale fiber morphologies and that using stochastic properties produced a 3% coefficient of variation of strength for all experiments. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Stochastic systems

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COMPARISON OF MICROMECHANICS THEORIES FOR modeling CHOPPED CARBON FIBER POLYMER MATRIX COMPOSITES 23

COMPARISON OF MICROMECHANICS THEORIES FOR MODELING CHOPPED C...

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23rd International Conference on Composite Materials, ICCM 2023

作者： Pineda, Evan J. Kaleel, Ibrahim Bednarcyk, Brett A. Miller, Sandi G. Multiscale and Multiphysics Modeling Branch NASA Glenn Research Center Cleveland United States NASA Postdoctoral Program Oak Ridge Associated Universities Cleveland United States Ceramic and Polymer Composites Branch NASA Glenn Research Center Cleveland United States

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New Capabilities and Improvements to the High-Order Glenn Flux Reconstruction Code

New Capabilities and Improvements to the High-Order Glenn Fl...

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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Spiegel, Seth C. Yoder, Dennis A. Debonis, James R. Huynh, H.T. Heinlein, Gregory S. Borghi, Michael R. Georgiadis, Nicholas J. Inlets and Nozzles Branch NASA Glenn Research Center ClevelandOH44135 United States Multiscale and Multiphysics Modeling Branch NASA Glenn Research Center ClevelandOH44135 United States Turbomachinery and Turboelectric Systems Branch NASA Glenn Research Center ClevelandOH44135 United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

The Glenn Flux Reconstruction (GFR) code is a computational fluid dynamics (CFD) code under development at NASA Glenn Research Center. GFR is based on the high-order flux reconstruction (FR) method and provides a large-eddy simulation (LES) capability that is both accurate and efficient for complex aeropropulsion flows. Three significant new capabilities have been added to the code that improve its performance and functionality. First, a variety of explicit Runge-Kutta methods, including some with adaptive time stepping, were added to GFR with two methods offering a 33% improvement in time-to-solution. Second, GFR can now utilize fully unstructured, mixed-element meshes to more easily facilitate the grid generation process for complex geometries. Finally, a rotating reference frame capability has been added to GFR for solving rotating turbomachinery problems. A selection of results demonstrating these new capabilities are presented in this work. The Taylor-Green vortex problem is used to verify the new unstructured capability by showing similar accuracy and resolution for all element types. LES of the Turbulent Heat Flux Phase III (THX3) experiment with comparison to another high-order LES code and a popular Reynolds-averaged Navier-Stokes (RANS) code demonstrates the accuracy of the code for complex aeropropulsion flows. Finally, LES of a spacecraft cabin ventilation fan shows the ability of GFR to efficiently establish a fan performance map and identify operating points for further analysis at high orders of accuracy. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Computational fluid dynamics

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Damage Initiation of Continuous Fiber Laminated Thermoplastic Composites 38

Damage Initiation of Continuous Fiber Laminated Thermoplasti...

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38th Technical Conference of the American Society for Composites, ASC 2023

作者： Buenrostro, Javier Miller, Sandi G. Ricks, Trenton M. Periera, J. Michael Universities Space Research Association ClevelandOH44135 United States Ceramic and Polymer Composites Branch NASA Glenn Research Center ClevelandOH44135 United States Multiscale and Multiphysics Modeling Branch NASA Glenn Research Center ClevelandOH44135 United States Structural Dynamics Branch NASA Glenn Research Center ClevelandOH44135 United States

ISBN: (纸本)9781605956916

The use of advanced thermoplastic composites (TPC) for structural applications in the aerospace and automotive industries has grown increasingly popular due to their high performance, high manufactured part output, and sustainability. Advanced manufacturing processes of thermoplastic composites allow for the building of complex optimized structural geometries with both continuous and discontinuous fibers. With more complex parts and processes comes the need for established qualification methodologies. Characterization of damage evolution from different manufacturing processes needs to be further explored to better understand the behavior of TPC for aerospace environments. Investigation into the differences in the damage behavior of continuous and discontinuous laminated TPC in tension and compression is important for aerospace applications where impact and crush damage is likely. Experiments using continuous fiber laminated IM7/PEKK TPC, [±45]4s specimens loaded in tension and [90/0]3s specimens loaded in compression, are performed to obtain stress vs strain curves with Digital Image Correlation (DIC) and acoustic emission (AE) transducers to monitor damage initiation and evolution. Next, interrupted low-cycle mechanical tests are performed on [±45]4s laminates with optical microscopy in between cycles to support characterization and understanding of the relevant damage mechanisms needed for material models. The damage mechanisms in laminated composites are of interest to better understand the effects of different fiber architectures on the laminate scale behavior, which can be used to calibrate continuum damage mechanics models. © 2023 by DEStech Publications, Inc. and American Society for Composites. All rights reserved.

关键词： Laminated composites

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multiscale failure analysis of a 3D woven composite containing manufacturing induced voids and disbonds

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Composites Part A: Applied Science and Manufacturing 2022年 156卷

作者： Pineda, Evan J. Bednarcyk, Brett A. Ricks, Trenton M. Farrokh, Babak Jackson, Wade Multiscale and Multiphysics Modeling Branch NASA Glenn Research Center ClevelandOH44135 United States Mechanical Systems Analysis and Simulation Branch NASA Goddard Space Flight Center GreenbeltMD20771 United States Damage Tolerance and Reliability Branch NASA Langley Research Center HamptonVA23681 United States

multiscale failure simulations of a three-dimensional woven composite repeating unit cell considering six scales, spanning the woven composite mesoscale to the sub-microscale voids, have been performed. The multiscale recursive micromechanics approach, which enables recursive integration of general micromechanics theories over an arbitrary number of length scales, has been employed within the NASA multiscale Analysis Tool. The multiscale model uses both the generalized method of cells and Mori-Tanaka micromechanics theories and considers failure in the constituent materials using a simple damage model. Baseline results, from a model of a composite containing distributed voids, are compared to uniaxial experimental data for an AS4 carbon fiber/ RTM6 epoxy matrix orthogonal three-dimensional woven composite with good agreement in terms of global stiffness and global failure stress. The multiscale model is then used to examine the nonlinear response of the material to other loading conditions. Case studies, motivated by X-ray computed tomography data, are presented on the effects of manufacturing induced voids and cracks. © 2022

关键词： Computerized tomography

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Determination of the Thermal Conductivity of Gas-Hydrate-Containing Porous Media using Discrete Geometric Analogues

Determination of the Thermal Conductivity of Gas-Hydrate-Con...

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2022 IEEE International Multi-Conference on Engineering, Computer and Information Sciences, SIBIRCON 2022

作者： Markov, Sergey I. Shurina, Ella P. Itkina, Natalya B. Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Lab. of Math. Modeling of Multiphysics Phenomena in Native and Artif. Multiscale Heterogeneous Media Department of Computer Technologies Novosibirsk State Technical University Novosibirsk Russia Laboratory of Analysis and Optimization of Nonlinear Systems Institute of Computational Technologies Novosibirsk State Technical University SB RAS Department of Computer Technologies Novosibirsk Russia

ISBN: (纸本)9781665464802

This work deals with the problem of reconstructing the thermal conductivity coefficient of ice-gas-hydrate rocks. It is proposed to use the results of direct mathematical simulation of heat transfer processes in a heterogeneous porous medium with different phase composition, and the principles of energy conservation law. The results of high-resolution X-ray tomography are applied to construct a digital model of the gas-hydrate-containing medium using machine learning procedure and special thresholding methods. A discrete geometrical model of the digital model is constructed by methods based on adapted symplectic partitions. In contrast to existing solutions to the above problem, our approach is not based on the application of phenomenological reduced models. We apply continuum models of the medium under study, and the heat transfer process. This approach makes it possible to obtain physically relevant results for determining the thermal conductivity coefficient of a heterogeneous medium using its digital analogue. The influence of the phase composition and contrast of the thermal characteristics on the value of thermal conductivity coefficient of ice-gas-hydrate-containing samples is presented. © 2022 IEEE.

关键词： Porous materials

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Multi-Scale Experimental Characterization for LS-DYNA MAT213 modeling of Composite Structures under High Strain Rate

arXiv

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arXiv 2024年

作者： Black, Jackob Premo, Ryan Goldberg, Robert K. Asce, F. Ricks, Trenton M. Lyons, Troy Kim, Han-Gyu Mississippi State University Department of Aerospace Engineering Mississippi StateMS39762 United States NASA Glenn Research Center Ceramic and Polymer Composites Branch ClevelandOH44135 United States NASA Glenn Research Center Multiscale and Multiphysics Modeling Branch ClevelandOH44135 United States NASA Glenn Research Center Structural Dynamics Branch ClevelandOH44135 United States

Aerospace structures often experience high strain rate events such as ballistic impact, crash, or crush. A material model has been developed that enhances the capability to simulate the dynamic response of composite materials under these loading conditions. The material model has been implemented into the commercially available transient dynamic finite element code LS-DYNA as MAT213. The model can simulate the nonlinear deformation, damage, and failure that takes place in a composite under dynamic loading conditions. The specific goal of this work is to characterize the MAT213 input for the representative material. The specific composite material being examined consists of T700G unidirectional carbon fibers and a low-melt PolyArylEtherKetone (LMPAEK) thermoplastic resin system. It is formally referred to as Toray TC1225 LMPAEK T700G. As the initial part of this work, this paper is focused on characterizing the material parameters for the MAT213 deformation model based on results obtained from multi-scale experimentation. The effort concentrated on characterizing the in-plane material response suitable for use with thin shell elements. For shell elements within MAT213, tabulated stress-strain results from tension and compression tests in the longitudinal and transverse directions and in-plane shear tests are required. Due to the difficulty of measuring small strains in the transverse direction, a multi-scale testing method was developed. Macro-scale testing is performed per the typical ASTM methods while micro-scale testing uses a microscope along with smaller coupon sizes to obtain the smaller strains in the transverse direction of each test. For both testing methods, a VIC-2D camera and software for DIC (Digital Image Correlation) analysis are used. Using the DIC combined with each test fixture, reliable stress and strain data are collected. This material was characterized based on this data. Single-element simulations are then executed to validate that the results

关键词： Dynamic response

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Hybrid experimental and numerical characterization of the 3D response of woven polymer matrix composites 36

Hybrid experimental and numerical characterization of the 3D...

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36th Technical Conference of the American Society for Composites 2021: Composites Ingenuity Taking on Challenges in Environment-Energy-Economy, ASC 2021

作者： Buenrostro, Javier Kim, Hyonny Goldberg, Robert K. Ricks, Trenton M. Department of Structural Engineering University of California San Diego 9500 Gilman Drive La Jolla CA92093 United States Ceramic and Polymer Composites Branch NASA Glenn Research Center ClevelandOH44135 United States Multiscale and Multiphysics Modeling Branch NASA Glenn Research Center ClevelandOH44135 United States

ISBN: (纸本)9781713837596

The need for advanced material models to simulate the deformation, damage, and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased usage in the aerospace and automotive industries. The purpose of this work is to characterize carbon epoxy fabrics for composite material models that rely on a large number of input parameters to define their nonlinear and 3D response;e.g. elastic continuum damage mechanics models or plasticity damage models [1, 2]. It is challenging to obtain large sets of experimental stress-strain curves, therefore, careful selection of physical experiments that exhibit nonlinear behavior is done to significantly reduce the cost of generating three-dimensional material databases. For this work, plain weave carbon fabrics with 3k and 12k tows are manufactured by VARTM. Testing is done using MTS hydraulic test frames and 2D digital image correlation (DIC) to obtain experimental stress-strain curves for in-plane tension and shear as well as transverse shear. For cases where actual experimental data is either not available or difficult to obtain, the required model input is virtually generated using the NASA Glenn developed Micromechanics Analysis Method/Generalized Method of Cells (MAC/GMC) code. A viscoplastic polymer model is calibrated and utilized to model the matrix constituent within a repeating unit cell (RUC) of a plain weave carbon fiber fabric. Verification and validation of this approach is done using MAT213, a tabulated orthotropic material model in the finite element code LS-DYNA, which relies on 12 input stress-strain curves in various coordinate directions [2]. Based on the model input generated by the micromechanics analyses in combination with available experimental data, a series of coupon level verification and validation analyses are carried out using the MAT 213 composite model. © 2021 36th Technical Conference of the American Society for Composites 2021: Composit

关键词： Stress-strain curves

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multiscale failure analysis of a 3D woven unit cell containing defects 35

Multiscale failure analysis of a 3D woven unit cell containi...

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35th Annual American Society for Composites Technical Conference, ASC 2020

作者： Pineda, Evan J. Bednarcyk, Brett A. Ricks, Trent M. Farrokh, Babak Jackson, Wade Multiphysics and Multiscale Modeling NASA Glenn Research Center ClevelandOH44135 United States Mechanical Systems Analysis and Simulation Branch NASA Goddard Space Flight Center GreenbeltMD20771 United States Durability Damage Tolerance Reliability Branch NASA Langley Research Center HamptonVA23681 United States

ISBN: (纸本)9781605956657

multiscale failure simulations have been performed for a Three-dimensional woven composite unit cell considering five, or more, length scales spanning the woven composite mesoscale to the sub-microscale voids. The multiscale recursive micromechanics approach, which enables recursive integration of general micromechanics theories over an arbitrary number of length scales, has been employed within the NASA multiscale Analysis Tool. The multiscale model uses both the generalized method of cells and Mori-Tanaka micromechanics theories, and considers failure in the constituent materials using a simple damage model. Baseline results, containing distributed voids, are compared to uniaxial experimental data for an AS4 carbon fiber/ RTM6 epoxy matrix 3D orthogonal woven composite with good agreement in terms of global stiffness and global failure stress. The simulations demonstrate that the 3D woven composite exhibits damage tolerance through sustaining increasing axial load far beyond the first initiation of damage. The multiscale model is used to examine the nonlinear response of the material to other loading conditions. Case studies, motivated by X-ray computed tomography data, are presented on the effects of manufacturing induced voids and cracks. © ASC 2020.

关键词： NASA

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Determination of the Thermal Conductivity of Gas-Hydrate-Containing Porous Media using Discrete Geometric Analogues

Determination of the Thermal Conductivity of Gas-Hydrate-Con...

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IEEE Region 8 International Conference on Computational Technologies in Electrical and Electronics Engineering, SIBIRCON

作者： Sergey I. Markov Ella P. Shurina Natalya B. Itkina Department of Computer Technologies Novosibirsk State Technical University Laboratory of Mathematical Modeling of Multiphysics Phenomena in Native and Artificial Multiscale Heterogeneous Media Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Novosibirsk Russia SB RAS Department of Computer Technologies Laboratory of Analysis and Optimization of Nonlinear Systems Institute of Computational Technologies Novosibirsk State Technical University Novosibirsk Russia

ISBN: (纸本)9781665464819

This work deals with the problem of reconstructing the thermal conductivity coefficient of ice-gas- hydrate rocks. It is proposed to use the results of direct mathematical simulation of heat transfer processes in a heterogeneous porous medium with different phase composition, and the principles of energy conservation law. The results of high-resolution X-ray tomography are applied to construct a digital model of the gas-hydrate-containing medium using machine learning procedure and special thresholding methods. A discrete geometrical model of the digital model is constructed by methods based on adapted symplectic partitions. In contrast to existing solutions to the above problem, our approach is not based on the application of phenomenological reduced models. We apply continuum models of the medium under study, and the heat transfer process. This approach makes it possible to obtain physically relevant results for determining the thermal conductivity coefficient of a heterogeneous medium using its digital analogue. The influence of the phase composition and contrast of the thermal characteristics on the value of thermal conductivity coefficient of ice-gas-hydrate-containing samples is presented.

关键词： Adaptation models Computational modeling Thermal engineering Conductivity X-ray tomography Rocks Mathematical models

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