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Book Effects of Cyclic Loading on Fibre Reinforced Titanium Metal Matrix Composites

Download or read book Effects of Cyclic Loading on Fibre Reinforced Titanium Metal Matrix Composites written by Silvia Zamperini and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Life Prediction Methodology for Titanium Matrix Composites

Download or read book Life Prediction Methodology for Titanium Matrix Composites written by W. Steven Johnson and published by ASTM International. This book was released on 1996 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Book Monitoring Damage Growth in Titanium Matrix Composites Using Acoustic Emission

Download or read book Monitoring Damage Growth in Titanium Matrix Composites Using Acoustic Emission written by and published by . This book was released on 1993 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Prediction of Damage Evolution in Continuous Fiber Metal Matrix Composites Subjected to Fatigue Loading

Download or read book Prediction of Damage Evolution in Continuous Fiber Metal Matrix Composites Subjected to Fatigue Loading written by and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A life prediction model is being developed by the authors for application to metal matrix composites (MMC's). The systems under study are continuous silicon carbide fibers imbedded in titanium matrix. The model utilizes a computationally based framework based on thermodynamics and continuum mechanics, and accounts for matrix inelasticity, damage evolution, and environmental degradation due to oxidation. The computational model utilizes the finite element method, and an evolutionary analysis of a unit cell is accomplished via a time stepping algorithm. The computational scheme accounts for damage growth such as fiber-matrix debonding, surface cracking, and matrix cracking via the inclusion of cohesive zone elements in the unit cell. These elements are located based on experimental evidence also obtained by the authors. The current paper outlines the formulation utilized by the authors to solve this problem, and recent results are discussed. Specifically, results are given for a four-ply unidirectional composite subjected to cyclic fatigue loading at 650°C both in air and inert gas. The effects of oxidation on the life of the composite are predicted with the model, and the results are compared to limited experimental results.

Book Time dependent Deformation of Titanium Metal Matrix Composites

Download or read book Time dependent Deformation of Titanium Metal Matrix Composites written by and published by . This book was released on 1995 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Damage Modeling of a Transversely Loaded Titanium Matrix Composite Under Cyclic Conditions

Download or read book Damage Modeling of a Transversely Loaded Titanium Matrix Composite Under Cyclic Conditions written by RW. Neu and published by . This book was released on 1999 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The life-limiting loading configuration of weakly bonded unidirectional titanium matrix composites is often transverse cyclic loading. Most fatigue tests under this loading configuration have been conducted at maximum stress levels above the monotonic proportional limit. However, the fatigue behavior at maximum stress levels below the monotonic proportional limit is often of interest, yet little work has been performed to identify this region on the fatigue life diagram. This investigation examined the behavior of a 16-ply SCS-9/Timetal 21S composite loaded transversely under generally low amplitude fatigue conditions. The fatigue limit under this loading configuration was found to be about one half the proportional limit. Residual strength tests were then conducted to determine the state of damage through measuring the change in stiffness using a number of unloading and reloading events. A damage mechanics methodology was demonstrated as a means to quantify the effects of the fatigue damage on the mechanical performance.

Book Time Dependent Deformation of Titanium Metal Matrix Composites

Download or read book Time Dependent Deformation of Titanium Metal Matrix Composites written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-15 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Book Durability and Damage Tolerance of High Temperature Advanced Titanium Metal Matrix Composites

Download or read book Durability and Damage Tolerance of High Temperature Advanced Titanium Metal Matrix Composites written by and published by . This book was released on 2000 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bridging fatigue crack growth damage mechanisms in a unidirectional SiC/Ti MMC include matrix cracking, fiber/matrix interface debonding and sliding along bridging fibers and fracture of these fibers. The basic components of these mechanisms are examined in this program. The evolution features of residual stresses indicated that stress relaxation occurred in the Ti matrix phase of the composite following post-fabrication cool down to 600 00. Parametric study of the SiC fiber coating materials showed that the effective residual stress component has an inverse relationship with the thickness of the fiber reaction zone. The debonding shear strength of the composite is determined by the localized shear stress distribution along the fiber/matrix interface at the onset of debonding. An interphase debonding model, which combine fracture mechanics with FE results on interphase shear stress and bridging fiber traction range, is proposed to establish a distribution of debonding lengths along a fiber-bridged matrix crack length as a function of temperature. The driving force for the interface debond crack, however, has an inverse relationship with the test temperature. The concurrent damage events of fiber stress evolution and continuous fiber strength degradation were postulated into a fiber fracture criterion to describe the fracture process of a bridging fiber. Furthermore, the fiber crack density has been correlated with the density of crack initiation sites observed in the interphase region along the reinforcing fibers in a SCS-6/Ti-21S composite.