Inelasticity and Micromechanics of Metal Matrix Composites

Inelasticity and Micromechanics of Metal Matrix Composites
Author: George Voyiadjis
Publisher: Elsevier
Total Pages: 358
Release: 2017-05-04
Genre: Technology & Engineering
ISBN: 1483290441

This book contains fifteen papers based on the presentations made at the symposium on "Inelasticity and Micromechanics of Metal Matrix Composites" held at the University of Washington, USA, in mid-1994. The papers represent the most recent work conducted on inelasticity and micromechanics of metal matrix composites. The book is divided into two parts: Part I deals with the study of inelastic deformation in metal matrix composites, while Part II tackles the micromechanical aspects of metal matrix composites. The articles discuss different aspects of these two topics ranging from purely theoretical treatments to extensive experimental investigations. Many of the papers are by prominent researchers working in this area.

Inelastic Deformation of Metal Matrix Composites

Inelastic Deformation of Metal Matrix Composites
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 210
Release: 2018-07-25
Genre:
ISBN: 9781724253149

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...

Local Stresses in Metal Matrix Composites Subjected to Thermal and Mechanical Loading

Local Stresses in Metal Matrix Composites Subjected to Thermal and Mechanical Loading
Author: AL. Highsmith
Publisher:
Total Pages: 17
Release: 1990
Genre: Ceramic-matrix composites
ISBN:

One of the important damage mechanisms in metal matrix composites is fiber/matrix separation. The interfacial region between the fiber and matrix is typically brittle and relatively weak, and therefore failure in this region may precede failure of the fiber and matrix. An elasticity solution has been used to analyze matrix stresses near the fiber/matrix interface in continuous fiber reinforced metal matrix composites. This micromechanics model consists of a cylindrical fiber and cylindrical sheath of matrix embedded in an orthotropic media representing the composite. The micromechanics model is used to predict thermal and mechanical properties for a lamina. These properties are then used in a laminate analysis to determine ply level stresses caused by a thermomechanical loading of the laminate. Finally, for a given ply, the ply level stresses and thermal loading are used in the micromechanics model in order to predict local stresses near the fiber/matrix interface.

Metal Matrix Composites

Metal Matrix Composites
Author: Minoru Taya
Publisher: Elsevier
Total Pages: 275
Release: 2016-01-11
Genre: Technology & Engineering
ISBN: 1483191133

Metal Matrix Composites: Thermomechanical Behavior discusses metal matrix composites, elaborating on that consists of two phases—fiber as reinforcement and metal as matrix. This book focuses on polymer matrix composites, including topics in metal matrix composites ranging from processing to fracture mechanics. The three basic types of composite materials—dispersion-strengthened, particle-reinforced, and fiber (whisker)-reinforced, are also described in detail. Dispersion-strengthened is characterized by a microstructure consisting of an elemental matrix within which fine particles are uniformly dispersed, while particle-reinforced is indicated by dispersed particles of greater than 1.0 μm diameter with a volume fraction of 5 to 40%. Fiber (whisker)-reinforced provides a distinguishing microstructural feature of fiber-reinforced materials, such as that the reinforcing fiber has one long dimension, while the reinforcing particles of the other two types do not. This publication serves as a reference data book to students and researchers aiming to acquire knowledge of the thermomechanical behavior of metal matrix composites.

A Comparison of Analysis Tools for Predicting the Inelastic Cyclic Response of Cross-Ply Titanium Matrix Composites

A Comparison of Analysis Tools for Predicting the Inelastic Cyclic Response of Cross-Ply Titanium Matrix Composites
Author: D. Coker
Publisher:
Total Pages: 31
Release: 1996
Genre: Cross-ply composites
ISBN:

Several micromechanical models that are currently being used for predicting the thermal and mechanical behavior of a cross-ply, [0/90], titanium matrix composite are evaluated. Six computer programs or methods are compared: (1) VISCOPLY; (2) METCAN; (3) FIDEP, an enhanced concentric cylinder model; (4) LISOL, a modified method of cells approach; (5) an elementary approach where the [90] ply is assumed to have the same properties as the matrix; and (6) a finite element method. Comparisons are made for the thermal residual stresses at room temperature resulting from processing, as well as for stresses and strains in two isothermal and two thermomechanical fatigue test cases. For each case, the laminate response of the models is compared to experimental behavior, while the responses of the constituents are compared among the models. The capability of each model to predict frequency effects, inelastic cyclic strain (hysteresis) behavior, and strain ratchetting with cycling is shown. The basis of formulation for the micromechanical models, the constitutive relationships used for the matrix and fiber, and the modeling technique of the [90] ply are all found to be important factors for determining the accurate behavior of the [0/90] composite.

Influence of Fiber Architecture on the Elastic an D Inelastic Response of Metal Matrix Composites

Influence of Fiber Architecture on the Elastic an D Inelastic Response of Metal Matrix Composites
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 72
Release: 2018-07-08
Genre:
ISBN: 9781722490706

This three part paper focuses on the effect of fiber architecture (i.e., shape and distribution) on the elastic and inelastic response of metal matrix composites. The first part provides an annotative survey of the literature, presented as a historical perspective, dealing with the effects of fiber shape and distribution on the response of advanced polymeric matrix and metal matrix composites. Previous investigations dealing with both continuously and discontinuously reinforced composites are included. A summary of the state-of-the-art will assist in defining new directions in this quickly reviving area of research. The second part outlines a recently developed analytical micromechanics model that is particularly well suited for studying the influence of these effects on the response of metal matrix composites. This micromechanics model, referred to as the generalized method of cells (GMC), is capable of predicting the overall, inelastic behavior of unidirectional, multi-phased composites given the properties of the constituents. In particular, the model is sufficiently general to predict the response of unidirectional composites reinforced by either continuous or discontinuous fibers with different inclusion shapes and spatial arrangements in the presence of either perfect or imperfect interfaces and/or interfacial layers. Recent developments regarding this promising model, as well as directions for future enhancements of the model's predictive capability, are included. Finally, the third pan provides qualitative results generated using GMC for a representative titanium matix composite system, SCS-6/TlMETAL 21S. Results are presented that correctly demonstrate the relative effects of fiber arrangement and shape on the longitudinal and transverse stress-strain and creep response, with both strong and weak fiber/matrix interfacial bonds. The fiber arrangements include square, square diagonal, hexagonal and rectangular periodic arrays, as well as a random array. The f...

Thermomechanical Response of Shape Memory Alloy Hybrid Composites

Thermomechanical Response of Shape Memory Alloy Hybrid Composites
Author: Travis L. Turner
Publisher: DIANE Publishing
Total Pages: 239
Release: 2001
Genre: Actuators
ISBN: 1428996133

This study examines the use of embedded shape memory alloy (SMA) actuators for adaptive control of the thermomechanical response of composite structures. A nonlinear thermomechanical model is presented for analyzing shape memory alloy hybrid composite (SMAHC) structures exposed to steady-state thermal and dynamic mechanical loads. Also presented are (1) fabrication procedures for SMAHC specimens, (2) characterization of constituent materials for model quantification, (3) development of the test apparatus for conducting static and dynamic experiments on specimens with and without SMA, (4) discussion of the experimental results, and (5) validation of the analytical and numerical tools developed in the study. Excellent agreement is achieved between the predicted and measured SAMHC responses including thermal buckling, thermal post-buckling and dynamic response due to inertial loading.