Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781719393836
Category :
Languages : en
Pages : 46
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Book Description
This document provides an overview of recent accomplishments and lessons learned in the development of general progressive damage analysis methods for predicting the residual strength and life of composite structures. These developments are described within their State-of-the-Art (SoA) context and the associated technology barriers. The emphasis of the authors is on developing these analysis tools for application at the structural level. Hence, modeling of damage progression is undertaken at the mesoscale, where the plies of a laminate are represented as a homogenous orthotropic continuum. The aim of the present effort is establish the ranges of validity of available models, to identify technology barriers, and to establish the foundations of the future investigation efforts. Such are the necessary steps towards accurate and robust simulations that can replace some of the expensive and time-consuming "building block" tests that are currently required for the design and certification of aerospace structures. Rose, Cheryl A. and Davila, Carlos G. and Leone, Frank A. Langley Research Center COMPOSITE STRUCTURES; AIRCRAFT STRUCTURES; DAMAGE ASSESSMENT; RESIDUAL STRENGTH; STRUCTURAL ANALYSIS; MATHEMATICAL MODELS; LESSONS LEARNED; MESOSCALE PHENOMENA; LAMINATES; CONTINUUMS; PREDICTIONS
Author: Cheryl A. Rose
Publisher:
ISBN:
Category :
Languages : en
Pages : 41
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Book Description
Author: Pengfei Liu
Publisher: Elsevier
ISBN: 0128209631
Category : Technology & Engineering
Languages : en
Pages : 396
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Book Description
Damage Modeling of Composite Structures: Strength, Fracture, and Finite Element Analysis provides readers with a fundamental overview of the mechanics of composite materials, along with an outline of an array of modeling and numerical techniques used to analyze damage, failure mechanisms and safety tolerance. Strength prediction and finite element analysis of laminated composite structures are both covered, as are modeling techniques for delaminated composites under compression and shear. Viscoelastic cohesive/friction coupled model and finite element analysis for delamination analysis of composites under shear and for laminates under low-velocity impact are all covered at length. A concluding chapter discusses multiscale damage models and finite element analysis of composite structures. Integrates intralaminar damage and interlaminar delamination under different load patterns, covering intralaminar damage constitutive models, failure criteria, damage evolution laws, and virtual crack closure techniques Discusses numerical techniques for progressive failure analysis and modeling, as well as numerical convergence and mesh sensitivity, thus allowing for more accurate modeling Features models and methods that can be seamlessly extended to analyze failure mechanisms and safety tolerance of composites under more complex loads, and in more extreme environments Demonstrates applications of damage models and numerical methods
Author: Pengfei Liu
Publisher: Elsevier
ISBN: 0323853536
Category : Technology & Engineering
Languages : en
Pages : 398
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Book Description
Damage Modeling of Composite Structures: Strength, Fracture, and Finite Element Analysis provides readers with a fundamental overview of the mechanics of composite materials, along with an outline of an array of modeling and numerical techniques used to analyze damage, failure mechanisms and safety tolerance. Strength prediction and finite element analysis of laminated composite structures are both covered, as are modeling techniques for delaminated composites under compression and shear. Viscoelastic cohesive/friction coupled model and finite element analysis for delamination analysis of composites under shear and for laminates under low-velocity impact are all covered at length. A concluding chapter discusses multiscale damage models and finite element analysis of composite structures. - Integrates intralaminar damage and interlaminar delamination under different load patterns, covering intralaminar damage constitutive models, failure criteria, damage evolution laws, and virtual crack closure techniques - Discusses numerical techniques for progressive failure analysis and modeling, as well as numerical convergence and mesh sensitivity, thus allowing for more accurate modeling - Features models and methods that can be seamlessly extended to analyze failure mechanisms and safety tolerance of composites under more complex loads, and in more extreme environments - Demonstrates applications of damage models and numerical methods
Author: René de Borst
Publisher: John Wiley & Sons
ISBN: 1118376013
Category : Technology & Engineering
Languages : en
Pages : 481
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Book Description
Built upon the two original books by Mike Crisfield and their own lecture notes, renowned scientist René de Borst and his team offer a thoroughly updated yet condensed edition that retains and builds upon the excellent reputation and appeal amongst students and engineers alike for which Crisfield's first edition is acclaimed. Together with numerous additions and updates, the new authors have retained the core content of the original publication, while bringing an improved focus on new developments and ideas. This edition offers the latest insights in non-linear finite element technology, including non-linear solution strategies, computational plasticity, damage mechanics, time-dependent effects, hyperelasticity and large-strain elasto-plasticity. The authors' integrated and consistent style and unrivalled engineering approach assures this book's unique position within the computational mechanics literature. Key features: Combines the two previous volumes into one heavily revised text with obsolete material removed, an improved layout and updated references and notations Extensive new material on more recent developments in computational mechanics Easily readable, engineering oriented, with no more details in the main text than necessary to understand the concepts. Pseudo-code throughout makes the link between theory and algorithms, and the actual implementation. Accompanied by a website (www.wiley.com/go/deborst) with a Python code, based on the pseudo-code within the book and suitable for solving small-size problems. Non-linear Finite Element Analysis of Solids and Structures, 2nd Edition is an essential reference for practising engineers and researchers that can also be used as a text for undergraduate and graduate students within computational mechanics.
Author: Rikard Benton Heslehurst
Publisher: CRC Press
ISBN: 146658047X
Category : Technology & Engineering
Languages : en
Pages : 216
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Book Description
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.
Author: Christos Kassapoglou
Publisher: John Wiley & Sons
ISBN: 1119013240
Category : Technology & Engineering
Languages : en
Pages : 252
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Book Description
Comprehensively covers new and existing methods for the design and analysis of composites structures with damage present Provides efficient and accurate approaches for analysing structures with holes and impact damage Introduces a new methodology for fatigue analysis of composites Provides design guidelines, and step by step descriptions of how to apply the methods, along with evaluation of their accuracy and applicability Includes problems and exercises Accompanied by a website hosting lecture slides and solutions
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722016609
Category :
Languages : en
Pages : 46
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Book Description
The translaminate fracture behavior of carbon/epoxy structural laminates with through-penetration notches was investigated to develop a residual strength prediction methodology for composite structures. An experimental characterization of several composite materials systems revealed a fracture resistance behavior that was very similar to the R-curve behavior exhibited by ductile metals. Fractographic examinations led to the postulate that the damage growth resistance was primarily due to fractured fibers in the principal load-carrying plies being bridged by intact fibers of the adjacent plies. The load transfer associated with this bridging mechanism suggests that a progressive damage analysis methodology will be appropriate for predicting the residual strength of laminates with through-penetration notches. A progressive damage methodology developed by the authors was used to predict the initiation and growth of matrix cracks and fiber fracture. Most of the residual strength predictions for different panel widths, notch lengths, and material systems were within about 10% of the experimental failure loads. Coats, Timothy W. and Harris, Charles E. Langley Research Center RTOP 538-13-11-05...
Author: Brandon M. Reynante
Publisher:
ISBN:
Category :
Languages : en
Pages : 285
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Book Description
The effects and importance of incorporating probabilistic aspects of the progression of damage in the analysis of composite structures are assessed. Two specific cases of graphite/epoxy with centrally-located holes are considered: a [0/90/±45], laminate subjected to equal biaxial tension, and a [±15/0],, laminate subjected to uniaxial tension. The variation in the basic composite material strength values are used with the maximum stress criteria to assess the probability of occurrence of various damage modes by evaluating the cumulative distribution functions of the corresponding material strength parameters at various locations in the structure for a given state of damage and applied load. An average stress approach is used in assessing the occurrence of both in-plane damage and delamination. Two-dimensional and threedimensional finite element models are used to obtain stress fields. In-plane damage is simulated by setting in-plane elastic constants of damaged elements effectively to zero. Out-of-plane damage is simulated by setting out-of-plane elastic constants of elements in adjacent plies effectively to zero. The results demonstrate that consideration of probabilistic characteristics of damage progression allows for the possibility of many different damage progression scenarios for a single laminate configuration, including the possibility of damage initiation and propagation via different damage modes (both in-plane and out-of-plane, as well as coupling between the two) and in numerous different geometric locations. Four key items that affect the probabilistic progressive damage behavior of the structure are identified: the particular details of the material strength distributions, the redistribution of stresses caused by the occurrence of damage, the damage history of the laminate including the modes and locations of all previous damage, and the nonlinear nature of failure probability as a function of stress. Recommendations are given to address some key issues in expanding the work. These include nonsymmetry of damage initiation and progression, use of strain energy release rate in assessing delamination, use of various material property degradation models to simulate damage, and consideration of probabilistic aspects of other material properties.
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720666653
Category :
Languages : en
Pages : 92
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Book Description
A progressive failure analysis method has been developed for predicting the failure of laminated composite structures under geometrically nonlinear deformations. The progressive failure analysis uses C(exp 1) shell elements based on classical lamination theory to calculate the in-plane stresses. Several failure criteria, including the maximum strain criterion, Hashin's criterion, and Christensen's criterion, are used to predict the failure mechanisms and several options are available to degrade the material properties after failures. The progressive failure analysis method is implemented in the COMET finite element analysis code and can predict the damage and response of laminated composite structures from initial loading to final failure. The different failure criteria and material degradation methods are compared and assessed by performing analyses of several laminated composite structures. Results from the progressive failure method indicate good correlation with the existing test data except in structural applications where interlaminar stresses are important which may cause failure mechanisms such as debonding or delaminations.Sleight, David W.Langley Research CenterLAMINATES; FAILURE ANALYSIS; INTERLAMINAR STRESS; STRUCTURAL DESIGN; DEFORMATION; COMPOSITE STRUCTURES; DAMAGE; PREDICTIONS; NONLINEARITY; DELAMINATING; DEBONDING (MATERIALS)
