Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures
Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-05-22

Total Pages: 44

ISBN-13: 9781719449342

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Stochastic-based, discrete-event progressive damage simulations of ceramic-matrix composite and polymer matrix composite material structures have been enabled through the development of a unique multiscale modeling tool. This effort involves coupling three independently developed software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/ Life), and (3) the Abaqus finite element analysis (FEA) program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating unit cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC. Abaqus is used at the global scale to model the overall composite structure. An Abaqus user-defined material (UMAT) interface, referred to here as "FEAMAC/CARES," was developed that enables MAC/GMC and CARES/Life to operate seamlessly with the Abaqus FEA code. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events, which incrementally progress and lead to ultimate structural failure. This report describes the FEAMAC/CARES methodology and discusses examples that illustrate the performance of the tool. A comprehensive example problem, simulating the progressive damage of laminated ceramic matrix composites under various off-axis loading conditions and including a double notched tensile specimen geometry, is described in a separate report. Nemeth, Noel N. and Bednarcyk, Brett A. and Pineda, Evan J. and Walton, Owen J. and Arnold, Steven M. Glenn Research Center STOCHASTIC PROCESSES; MICROCRACKS; SIMULATION; CERAMIC MATRIX COMPOSITES; POLYMER MATRIX COMPOSITES; FINITE ELEMENT METHOD; MICROMECHANICS; SOFTWARE DEVELOPMENT TOOLS; SOFTWARE ENGINEERING; DAMAGE; BRITTLE MATERIALS; COMPOSITE STRUCTURES; CRACK INITIATION; CRACK PROPAGATION; FRACTURE MECHANICS; PROBABILITY THEORY; STRESS-STRAIN RELATIONSHIPS; STRUCTURAL ANALYSIS

Practical Micromechanics of Composite Materials
Practical Micromechanics of Composite Materials

Author: Jacob Aboudi

Publisher: Butterworth-Heinemann

Published: 2021-08-31

Total Pages: 418

ISBN-13: 0128206381

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Practical Micromechanics of Composite Materials provides an accessible treatment of micromechanical theories for the analysis and design of multi-phased composites. Written with both students and practitioners in mind and coupled with a fully functional MATLAB code to enable the solution of technologically relevant micromechanics problems, the book features an array of illustrative example problems and exercises highlighting key concepts and integrating the MATLAB code. The MATLAB scripts and functions empower readers to enhance and create new functionality tailored to their needs, and the book and code highly complement one another. The book presents classical lamination theory and then proceeds to describe how to obtain effective anisotropic properties of a unidirectional composite (ply) via micromechanics and multiscale analysis. Calculation of local fields via mechanical and thermal strain concentration tensors is presented in a unified way across several micromechanics theories. The importance of these local fields is demonstrated through the determination of consistent Margins of Safety (MoS) and failure envelopes for thermal and mechanical loading. Finally, micromechanics-based multiscale progressive damage is discussed and implemented in the accompanying MATLAB code. - Emphasizes appropriate application of micromechanics theories to composite behavior - Addresses multiple popular micromechanics theories, which are provided in MATLAB - Discusses stresses and strains resulting from realistic thermal and mechanical loading - Includes availability of solution manual for professors using the book in the classroom

Scientific and Technical Aerospace Reports
Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1995

Total Pages: 602

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Fatigue Life Prediction of Composites and Composite Structures
Fatigue Life Prediction of Composites and Composite Structures

Author: Anastasios P. Vassilopoulos

Publisher: Woodhead Publishing

Published: 2019-10-08

Total Pages: 766

ISBN-13: 0081025769

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Fatigue Life Prediction of Composites and Composite Structures, Second Edition, is a comprehensive review of fatigue damage and fatigue life modeling and prediction methodologies for composites and their use in practice. In this new edition, existing chapters are fully updated, while new chapters are introduced to cover the most recent developments in the field. The use of composites is growing in structural applications in many industries, including aerospace, marine, wind turbine and civil engineering. However, there are uncertainties about their long-term performance, including performance issues relating to cyclic fatigue loading that hinder the adoption of a commonly accepted credible fatigue design methodology for the life prediction of composite engineering structures. With its distinguished editor and international team of contributors, this book is a standard reference for industry professionals and researchers alike. - Examines past, present and future trends associated with the fatigue life prediction of composite materials and structures - Assesses novel computational methods for fatigue life modeling and prediction of composite materials under constant amplitude loading - Covers a wide range of techniques for predicting fatigue, including their theoretical background and practical applications - Addresses new topics and covers contemporary research developments in the field

A New Time
A New Time

Author: Sue Mydliak

Publisher: Next Chapter

Published: 2022-02-02

Total Pages: 179

ISBN-13:

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With her home empty and her father missing, Elspeth's life is in shambles. A few days later, the villagers come for her and her mother, for practicing witchcraft. Held in the tollbooth in Dornoch, Scotland, Elspeth must find a way to escape and protect herself, and to go to the only place she knows for help... Arabels. With danger at their doorstep, can Elspeth discover the way to freedom and safety, or will danger find her again?

Multiscale Modeling and Simulation of Composite Materials and Structures
Multiscale Modeling and Simulation of Composite Materials and Structures

Author: Young Kwon

Publisher: Springer Science & Business Media

Published: 2007-12-04

Total Pages: 634

ISBN-13: 0387363181

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This book presents the state-of-the-art in multiscale modeling and simulation techniques for composite materials and structures. It focuses on the structural and functional properties of engineering composites and the sustainable high performance of components and structures. The multiscale techniques can be also applied to nanocomposites which are important application areas in nanotechnology. There are few books available on this topic.

Defects and Damage in Composite Materials and Structures
Defects and Damage in Composite Materials and Structures

Author: Rikard Benton Heslehurst

Publisher: CRC Press

Published: 2014-04-21

Total Pages: 216

ISBN-13: 146658047X

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The advantages of composite materials include a high specific strength and stiffness, formability, and a comparative resistance to fatigue cracking and corrosion. However, not forsaking these advantages, composite materials are prone to a wide range of defects and damage that can significantly reduce the residual strength and stiffness of a structure or result in unfavorable load paths. Emphasizing defect identification and restitution, Defects and Damage in Composite Materials and Structures explains how defects and damage in composite materials and structures impact composite component performance. Providing ready access to an extensive, descriptive list of defects and damage types, this must-have reference: Examines defect criticality in composite structures Recommends repair actions to restore structural integrity Discusses failure modes and mechanisms of composites due to defects Reviews NDI processes for finding and identifying defects in composite materials Relating defect detection methods to defect type, the author merges his experience in the field of in-service activities for composite airframe maintenance and repair with indispensable reports and articles on defects and damage in advanced composite materials from the last 50 years.

High-Performance Structural Fibers for Advanced Polymer Matrix Composites
High-Performance Structural Fibers for Advanced Polymer Matrix Composites

Author: National Research Council

Publisher: National Academies Press

Published: 2005-05-09

Total Pages: 70

ISBN-13: 0309181836

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Military use of advanced polymer matrix composites (PMC)â€"consisting of a resin matrix reinforced by high-performance carbon or organic fibersâ€"while extensive, accounts for less that 10 percent of the domestic market. Nevertheless, advanced composites are expected to play an even greater role in future military systems, and DOD will continue to require access to reliable sources of affordable, high-performance fibers including commercial materials and manufacturing processes. As a result of these forecasts, DOD requested the NRC to assess the challenges and opportunities associated with advanced PMCs with emphasis on high-performance fibers. This report provides an assessment of fiber technology and industries, a discussion of R&D opportunities for DOD, and recommendations about accelerating technology transition, reducing costs, and improving understanding of design methodology and promising technologies.