Download or read book Thermomechanical Fatigue of a Quasi Isotropic Metal Matrix Composite written by BS. Majumdar and published by . This book was released on 1991 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: In-phase thermomechanical fatigue (TMF) and elevated temperature isothermal fatigue (IF) experiments were conducted on a [0,±45,90]s Ti 15-3/SCS6 composite under load control. A correlation was obtained between the stabilized mechanical strain range and TMF life. TMF life was found to be significantly shorter than IF life when comparisons were made either on a stress-range or a gross mechanical strain-range basis. Damage modes were investigated using optical and scanning electron microscopy. The primary damage mode in IF specimens was transverse microcracking oriented perpendicular to the loading axis. In TMF specimens, although similar damage was observed very close to the fracture surface, the primary damage modes were inter-ply delamination and fiber-matrix debonding. Limited experiments were performed where damage was monitored using a replication technique on the specimen edges. These experiments confirmed delamination and debonding in TMF as well as thermally cycled specimens. Wavelength dispersive spectroscopic (WDS) analysis showed carbon-rich zones along many ply-to-ply interfaces, and these zones may have accelerated delamination cracking. Finite element analysis indicated that the maximum delamination stress occurred at the minimum temperature in the TMF experiments. The fatigue data of Ti 15-3/SCS6 composite, from this and other investigations, were plotted in the form of 0° fiber stress range versus logarithm of fatigue life. This phenomenological plot indicated a similar trend for various data sets, but the exact mechanisms remain to be determined.

Download or read book Behavior of a Quasi isotropic Ply Metal Matrix Composite Under Thermo mechanical and Isothermal Fatigue Loading written by Karl A. Hart (CAPT, USAF.) and published by . This book was released on 1992 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies on the Mechanism of Blood Coagulation and the Mode of Action of Vitamin K written by Bertus Marinus Bas and published by . This book was released on 1979 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of the Thermo Mechanical Fatigue Response of Metal Matrix Composite Laminates with Interfacial Normal and Shear Failure written by S. Mall and published by . This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, an analysis of the thermo-mechanical fatigue (TMF) behavior of titanium-based metal matrix composites (MMCs) is accomplished by employing a modified method of cells micromechanics model coupled with a fiber/matrix interfacial failure scheme and the Bodner-Partom unified constitutive theory. Interfacial failure is based on a probabilistic failure criterion which considers the equivalent interfacial compliance to be a function of the interfacial stress. In this approach, the effects of both normal and shear failure of the interface have been included. MMC laminates with angle-ply and quasi-isotropic layups are analyzed for monotonic, cyclic, and thermo-mechanical fatigue loads, and where it is appropriate, comparisons with experimental data are made.

Download or read book Thermomechanical fatigue behavior of materials written by Michael J. Verrilli and published by ASTM International. This book was released on 1996 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermomechanical Behavior of Advanced Structural Materials written by American Society of Mechanical Engineers. Winter Annual Meeting and published by . This book was released on 1993 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Role of Oxidation on the Thermo mechanical Fatigue of Timetal 21S Matrix Composites written by WS. Johnson and published by . This book was released on 2000 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Isothermal fatigue tests were performed on unnotched quasi-isotropic SCS-6/Timetal 21S (Ti-15Mo-2.6Nb-3Al-0.2Si) composites at room temperature, 400°C and 500°C with various hold times (0, 1 and 10 seconds). The specimen tested at 500°C showed significant oxidation, especially along the grain boundaries. In addition, there were changes in various physical properties of the composites at elevated temperatures: oxidation, phase transformation, viscoplastic flow of matrix, and interface reaction. The measurement of oxide thickness of both with and without load indicated that the oxidation of the matrix material was more severe with applied load than without load for the same amount of exposure time. Simple spectrum loading tests were conducted to examine the effect of test temperature on the formation of oxidation and its influence on the damage accumulation in the composites. Different numbers of applied cycles per block were used: n1 and n2 = 10, 100, and 1000 cycles. The change in temperature along with stress acted as thermal cycle that further introduced damages into the composites and reduced their life. As the number of applied cycles increased, the failure life of the composites was increased. The small number of cycles per block showed a shorter life due to more frequent changes in temperature level.

Download or read book Analysis of Thermomechanical Fatigue of Unidirectional Titanium Metal Matrix Composites written by and published by . This book was released on 1991 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Composite Materials written by T. Kevin O'Brien and published by ASTM International. This book was released on 1991 with total page 831 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Methodologies for Predicting the Thermomechanical Fatigue Life of Unidirectional Metal Matrix Composites written by RW. Neu and published by . This book was released on 1996 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parameters and models to correlate the cycles to failure of a unidirectional metal matrix composite (SCS-6/Timetal 21S) undergoing thermal and mechanical loading are examined. Three different cycle types are considered: out-of-phase thermomechanical fatigue (TMF), in-phase TMF, and isothermal fatigue. A single parameter based on either the fiber or matrix behavior is shown not to correlate the cycles to failure of all the data. Two prediction methods are presented that assume that life may be dependent on at least two fatigue damage mechanisms and therefore consist of two terms. The first method, the linear life fraction model, shows that by using the response of the constituents, the life of these different cycle types are better correlated using two simple empirical relationships: one describing the fatigue damage in the matrix and the other fiber-dominated damage. The second method, the dominant damage model, is more complex but additionally brings in the effect of the environment. This latter method improves the predictions of the effects of the maximum temperature, temperature range, and frequency, especially under out-of-phase TMF and isothermal fatigue. The steady-state response of the constituents is determined using a 1-D micromechanics model with viscoplasticity. The residual stresses due to the CTE mismatch between the fiber and matrix during processing are included in the analysis.

Download or read book An Investigation Into Thermomechanical Fatigue of Metal Matrix Composites written by Metin Karayaka and published by . This book was released on 1992 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental and theoretical approaches are used to characterize the thermomechanical deformation behavior of metal matrix composites. Experiments on unreinforced and SiC particulate reinforced Al 2xxx-T4 have been conducted under several mechanical strain-temperature phasing conditions. Based on stress range, substantial improvements in fatigue life have been observed. However, based on strain range, the effect of reinforcement on fatigue lives differs depending on the mechanical strain-temperature phasing, temperature, and strain rate. Several deformation mechanisms of unreinforced and reinforced Al 2xxx-T4 have been identified, including void formation, crack initiation, intergranular/transgranular crack growth, oxide penetration at the crack tips, crack deflection due to particle interference, and mean stress effects. Theoretical approaches include the development of a general micromechanistic constitutive equation, based on Eshelby's equivalent inclusion theory, and a life prediction methodology for metal matrix composites. Synergistic effects of particulate reinforcement on high temperature thermomechanical behavior are studied. The constitutive model provides insight into the internal stress-strain behavior, including effective and hydrostatic stresses, of both the matrix and the reinforcement developed during cyclic loading conditions. The deformation behavior of the constituents is used to develop an experimentally based micromechanistic life prediction model. The damage caused by internal stresses, oxidation, creep, and fatigue mechanisms as a function of reinforcement volume fraction is quantified for wide range of loading conditions.

Download or read book Thermomechanical and Isothermal Fatigue Behavior of a 90 sub 8 Titanium Matrix Composite written by and published by . This book was released on 1993 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Titanium Matrix Composites written by Shankar Mall and published by CRC Press. This book was released on 2020-01-29 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 review and summarise the advancements related to mechanical behavior and related mechanics issues of TMCs.

Download or read book Advances in Fatigue Lifetime Predictive Techniques written by Michael R. Mitchell and published by ASTM International. This book was released on 1996 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proposed Framework for Thermomechanical Life Modeling of Metal Matrix Composites written by Gary R. Halford and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermo mechanical Fatigue Behavior of Materials written by Huseyin Sehitoglu and published by ASTM International. This book was released on 2000 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IUTAM Symposium on Transformation Problems in Composite and Active Materials written by Yehia A. Bahei-El-Din and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of composite materials has seen substantial development in the past decade, New composite systems are being continually developed for various applications. Among such systems are metal, intermetallic, and superalloy matrix composites, carbon-carbon composites as well as polymer matrix composites. At the same time, a new discipline has emerged of active or smart materials, which are often constructed as composite or heterogeneous media and structures. One unifying theme in these diverse systems is the influence that uncoupled and coupled eigenfields or transformation fields exert on the various types of overall response, as well as on the respective phase responses. Problems of this kind are currently considered by different groups which may not always appreciate the similarities of the problems involved. The purpose of the IUTAM Symposium on Transformation Problems in Composite and Active Materials held in Cairo, Egypt from March 10 to 12, 1997 was to bring together representatives of the different groups so that they may interact and explore common aspects of these seemingly different problem areas. New directions in micromechanics research in both composite and active materials were also explored in the symposium. Specifically, invited lectures in the areas of inelastic behavior of composite materials, shape memory effects, functionally graded materials, transformation problems in composite structures, and adaptive structures were delivered and discussed during the three-day meeting. This book contains the printed contributions to the IUTAM Symposium.