Time-Dependent Deformation of Titanium Metal Matrix Composites Final Report C.A. Bigelow Et Al, Analytical Services and Materials, January 1995

Time-Dependent Deformation of Titanium Metal Matrix Composites Final Report C.A. Bigelow Et Al, Analytical Services and Materials, January 1995 PDF Author:
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Languages : en
Pages :

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Time-Dependent Deformation of Titanium Metal Matrix Composites

Time-Dependent Deformation of Titanium Metal Matrix Composites PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722907068
Category :
Languages : en
Pages : 36

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A three-dimensional finite element program called VISCOPAC was developed and used to conduct a micromechanics analysis of titanium metal matrix composites. The VISCOPAC program uses a modified Eisenberg-Yen thermo-viscoplastic constitutive model to predict matrix behavior under thermomechanical fatigue loading. The analysis incorporated temperature-dependent elastic properties in the fiber and temperature-dependent viscoplastic properties in the matrix. The material model was described and the necessary material constants were determined experimentally. Fiber-matrix interfacial behavior was analyzed using a discrete fiber-matrix model. The thermal residual stresses due to the fabrication cycle were predicted with a failed interface, The failed interface resulted in lower thermal residual stresses in the matrix and fiber. Stresses due to a uniform transverse load were calculated at two temperatures, room temperature and an elevated temperature of 650 C. At both temperatures, a large stress concentration was calculated when the interface had failed. The results indicate the importance of accuracy accounting for fiber-matrix interface failure and the need for a micromechanics-based analytical technique to understand and predict the behavior of titanium metal matrix composites. Bigelow, C. A. and Bahei-El-din, Y. A. and Mirdamadi, M. Unspecified Center NAS1-19708; RTOP 505-63-50-04...

Time-dependent Deformation of Titanium Metal Matrix Composites

Time-dependent Deformation of Titanium Metal Matrix Composites PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 36

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Life Prediction Methodology for Titanium Matrix Composites

Life Prediction Methodology for Titanium Matrix Composites PDF Author: W. Steven Johnson
Publisher: ASTM International
ISBN: 0803120397
Category : Metallic composites
Languages : en
Pages : 625

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Book Description
Papers presented at the March 1994 symposium are organized into five sections that progress from basic understanding of mechanical damage mechanisms and environmental effects to life prediction methodology. Five papers discuss the interplay between interfacial strength, residual thermal stresses, an

Titanium Matrix Composites

Titanium Matrix Composites PDF Author: Shankar Mall
Publisher: CRC Press
ISBN: 9781566765671
Category : Technology & Engineering
Languages : en
Pages : 482

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Book Description
A review and summary of advancements related to mechanical behavior and related mechanics issues of titanium matrix composites (TMCs), a class of high-temperature materials useful in the propulsion and airframe components in advanced aerospace systems. After an introduction to TMCs, different authors discuss the following topics: monotonic response, micromechanical theories, fiber-matrix interface, fatigue failure mechanisms, fatigue and thermomechanical fatigue life prediction, creep behavior, fatigue crack growth, notch strength, and micromechanical analysis and modeling. Annotation copyrighted by Book News, Inc., Portland, OR

Metal Matrix Composites

Metal Matrix Composites PDF Author: W. Steven Johnson
Publisher: ASTM International
ISBN: 080311270X
Category : Fracture mechanics
Languages : en
Pages : 289

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Book Description
Fourteen peer-reviewed papers on testing techniques, analysis approaches, and descriptions of various failure processes. From the Symposium on [title] held at Sparks, NV, April 1988. Annotation copyright Book News, Inc. Portland, Or.

Analysis of Thermomechanical Fatigue of Unidirectional Titanium Metal Matrix Composites

Analysis of Thermomechanical Fatigue of Unidirectional Titanium Metal Matrix Composites PDF Author: YA. Bahei-El-Din
Publisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 17

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Thermomechanical fatigue (TMF) data have been generated for a Ti-15V-3Cr-3Al-3Sn (Ti-15-3) material reinforced with SCS-6 silicon carbide fibers for both in-phase and out-of-phase testing. Significant differences in failure mechanisms and fatigue life are noted for the in-phase and out-of-phase testing. The purpose of the research reported in this paper is to apply a micromechanics model to analysis of the data. The analysis predicts the stresses in the fiber and in the matrix material during the thermal and mechanical cycling by calculating both the thermal and mechanical stresses and their time-dependent behavior. The rate-dependent behavior of the matrix was characterized and was used to calculate the constituent stresses in the composite. The predicted 0° fiber stress range was used to explain the composite failure. It was found that for a given condition, temperature, loading frequency, and time at temperature, the 0° fiber stress range may control the fatigue life of the unidirectional composite.

Aspects of High Temperature Damage in Fiber Reinforced Titanium Metal Matrix Composites

Aspects of High Temperature Damage in Fiber Reinforced Titanium Metal Matrix Composites PDF Author:
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ISBN:
Category :
Languages : en
Pages : 154

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Aspects associated with high temperature damage in fiber reinforced Metal Matrix Composites were investigated and are presented in this report in the form of five separate sections. In the first section, the fatigue and fatigue crack growth characteristics in neat laminates made of Timetal 21S were studied in relation to both temperature and loading frequency effects. The second section deals with the evolution of the thermal residual stresses in the composite when cooling from consolidation temperature or subjecting the composite to then-nal cycles. A new mechanical simulation method capable of measuring the induced residual stress on real; time basis has been developed in this study. The third section extends this issue to the time-dependent internal stress and strain states of MMCs under the thermomechanical loading conditions. Here, a new micromechanical model employing the four-phase concentric cylinder configuration has been proposed. Based on this model, the time-dependent behavior of continuous fiber reinforced metal matrix composites has been evaluated for the SCS-6/Timetal 21S composite. These results are presented in the fourth section. The last section of this report deals with the high temperature fatigue crack growth characteristics of the continuous fiber reinforced titanium metal matrix composite sigma l240/Timetal 12IS. The time- dependent features of the crack growth was examined in relation to the variation of both testing temperature and loading frequency. the principal damage mechanism of this composite under the load condition employed was identified to be the crack bridging and fiber/matrix debonding confined to regions near the crack surfaces ... Bridging, Fiber pullout length, Viscoplasticity, Composite interface.

A New Local Debonding Model with Application to the Transverse Tensile and Creep Behavior of Continuously Reinforced Titanium Composites

A New Local Debonding Model with Application to the Transverse Tensile and Creep Behavior of Continuously Reinforced Titanium Composites PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781726154420
Category :
Languages : en
Pages : 40

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A new, widely applicable model for local interfacial debonding in composite materials is presented. Unlike its direct predecessors, the new model allows debonding to progress via unloading of interfacial stresses even as global loading of the composite continues. Previous debonding models employed for analysis of titanium matrix composites are surpassed by the accuracy, simplicity, and efficiency demonstrated by the new model. The new model was designed to operate seamlessly within NASA Glenn's Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), which was employed to simulate the time- and rate-dependent (viscoplastic) transverse tensile and creep behavior of SiC/Ti composites. MAC/GMC's ability to simulate the transverse behavior of titanium matrix composites has been significantly improved by the new debonding model. Further, results indicate the need for a more accurate constitutive representation of the titanium matrix behavior in order to enable predictions of the composite transverse response, without resorting to recalibration of the debonding model parameters.Bednarcyk, Brett A. and Arnold, Steven M.Glenn Research CenterDEBONDING (MATERIALS); METAL MATRIX COMPOSITES; CREEP ANALYSIS; DEFORMATION; MODELS; TITANIUM; VISCOPLASTICITY...

Inelastic Deformation of Metal Matrix Composites

Inelastic Deformation of Metal Matrix Composites PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781724253149
Category :
Languages : en
Pages : 210

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Book Description
A theoretical model capable of predicting the thermomechanical response of continuously reinforced metal matrix composite laminates subjected to multiaxial loading was developed. A micromechanical model is used in conjunction with nonlinear lamination theory to determine inelastic laminae response. Matrix viscoplasticity, residual stresses, and damage to the fiber/matrix interfacial zone are explicitly included in the model. The representative cell of the micromechanical model is considered to be in a state of generalized plane strain, enabling a quasi two-dimensional analysis to be performed. Constant strain finite elements are formulated with elastic-viscoplastic constitutive equations. Interfacial debonding is incorporated into the model through interface elements based on the interfacial debonding theory originally presented by Needleman, and modified by Tvergaard. Nonlinear interfacial constitutive equations relate interfacial tractions to displacement discontinuities at the interface. Theoretical predictions are compared with the results of an experimental program conducted on silicon carbide/titanium (SiC/Ti) unidirectional, (O4), and angle-ply, (+34)(sub s), tubular specimens. Multiaxial loading included increments of axial tension, compression, torque, and internal pressure. Loadings were chosen in an effort to distinguish inelastic deformation due to damage from matrix plasticity and separate time-dependent effects from time-independent effects. Results show that fiber/matrix debonding is nonuniform throughout the composite and is a major factor in the effective response. Also, significant creep behavior occurs at relatively low applied stress levels at room temperature. Lissenden, C. J. and Herakovich, C. T. and Pindera, M-J. Unspecified Center NASA-CR-191522, AM-93-03, NAS 1.26:191522 NAG1-745; RTOP 506-73-43-03...