Composite materials, characterization

Grediac M. (2004) The use of full-field measurement methods in composite material characterization Interest and limitations, Composites-Part A Applied Science and Manufacturing, 35(7-8), 751-761. 

J. L. Rose, A. Pilarski, and Y. Huang, Surface Wave Utility in Composite Material Characterization, Res. Non-Destr. Eval., Vol. 1, pp. 247-265, Springer-Verlag, New York (1990). 

O Brien, T.K., Characterization of Delamination Onset and Growth in a Composite Laminate in Damage in Composite Materials, ASTM STP 775, p. 140-167,1982 Poursartip, A. Ashby, M. F., Beaumont P.W.R., The Fatigue Damage Mechanics of Fibrous Laminates in Proceedings of the European Workshop on Nondestructive Evaluation of Polymers and Polymer Matrix Composites, Polymer NDE (edited by Khg. Ashbee), Technomic Publishing, p. 250-260, 1984... 

Based upon a piezoelectric 1-3-composite material, air-bome ultrasonic probes for frequencies up to 2 MHz were developped. These probes are characterized by a bandwidth larger than 50 % as well as a signal-to-noise ratio higher than 100 dB. Applications are the thickness measurement of thin powder layers, the inspection of sandwich structures, the detection of surface near cracks in metals or ceramics by generation/reception of Rayleigh waves and the inspection of plates by Lamb waves. 

The increased use of composite materials in aireraft industry the last years has impliedagrowing need for efficient methods for nondestructive characterization of composite materials. One example is determination of porosity contents in composite specimens during manufacturing. Results have been reported [1], showing that the porosity contents can be estimated with good aceuracy by utilizing a linear relation between the frequeney dependenee of the attenuation, i.e., P = +1, where P is the porosity content, K and I are constants and where is the slope... 

As we have mentioned, the particular characterization task considered in this work is to determine attenuation in composite materials. At our hand we have a data acquisition system that can provide us with data from both PE and TT testing. The approach is to treat the attenuation problem as a multivariable regression problem where our target values, y , are the measured attenuation values (at different locations n) and where our input data are the (preprocessed) PE data vectors, u . The problem is to find a function iy = /(ii ), such that i), za jy, based on measured data, the so called training data. 

We have already discussed a number of applications of the SEM to materials characterization topographical (SE) imaging, Energy-Dispersive X-Ray analysis (EDS) and the use of backscattering measurements to determine the composition of binary alloy systems. We now shall briefly discuss applications that are, in part, spe-... 

Among the most important parameters for materials characterization are the compositions of binary Gej Sij ) alloys, ternary Ai B C (e.g.,... 

Rutherford back-scattering spectroscopy (RBS) is one of the most frequently used techniques for quantitative analysis of composition, thickness, and depth profiles of thin solid films or solid samples near the surface region. It has been in use since the nineteen-sixties and has since evolved into a major materials-characterization technique. The number and range of applications are enormous. Because of its quantitative feature, RBS often serves as a standard for other techniques. 

Manufacturing efficiency embodies a wide variety of topics far beyond the scope of this book. However, a materials utilization factor will be defined and characterized for composite materials and metals as a... 

Stnjcturai Design Guide for Advanced Composite Applications, Vol. 1, Material Characterization, 2nd edition. Advanced Composites Division, Air Force Materials Laboratory, January 1971. 

J. M. Whitney, N. J. Pagano, and R. B. Pipes, Design and Fabrication of Tubuiar Specimens for Composite Characterization, in Composite Materials Testing and Design (Second Conference), H. T. Corten (Chairman), Anaheim, Caiifomia, 20-22 April 1971, ASTM STP 497, American Society for Testing and Materials, 1972, pp. 52-67. 

Max E. Waddoups, Characterization and Design of Composite Materials, in Composite Materials Workshop, S. W. Tsai, J. C. Halpin, and Nicholas J. Pagano (Editors), St. Louis, Missouri, 13-21 July 1967, Technomic. Westporl, Connecticut, 1968, pp. 254-308. 

Because of the many types of damage and damage growth in composite materials, the initial state of the material is difficult, if not impossible, to characterize. Moreover, it is much more difficult to formulate a boundary-value problem to describe crack propagation in composite materials than in metals. 

The fundamental objective in this section is to describe the factors and procedures to select the right material for a specific structural application. The right stuff for a material, as for a fighter pilot or an astronaut, is a complex combination of characteristics. To select the proper material requires being able to characterize and evaluate various composite materials (or metalsl) and to compare their attractive characteristics with the behavioral features required for a particular structure. Finally, a materials selection example of a space truss design problem will be addressed. 

The type of interaction along the interface will exert a great influence on the various properties of the composite materials. Therefore, to improve the performance of a composite material, it is absolutely necessary to characterize the structures of the interface. Some of the methods for analysis of the interface are ESCA, AES, IR-FTIR, SIMS, and SEM, etc. At present, ESCA is widely used in the surface analysis of elements and the qualitative analysis of functional groups. Figure 11 shows the ESCA spectrum of polyethylene treated with... 

The data presented in Figure 8 graphically illustrate the tremendous and rapid growth in interest in FOSS chemistry, especially for patented applications. This looks set to continue with current applications in areas as diverse as dendrimers, composite materials, polymers, optical materials, liquid crystal materials, atom scavengers, and cosmetics, and, no doubt, many new areas to come. These many applications derive from the symmetrical nature of the FOSS cores which comprise relatively rigid, near-tetrahedral vertices connected by more flexible siloxane bonds. The compounds are usually thermally and chemically stable and can be modified by conventional synthetic methods and are amenable to the usual characterization techniques. The recent commercial availability of a wide range of simple monomers on a multigram scale will help to advance research in the area more rapidly. 

J. Gotz, N. Eisenreich, A. GeiSler, E. GeiSler 2002, (Characterization of the structure in highly filled composite materials by means of MRI), /. Propell., Explos., Pyrotechn. 27 (6), 1-6. 

Determination of Compositional Sequences. In the copolymerization of MMA and MAA or TBTM, compositional dyads and triads are generated. These sequences are determined by the relative concentration of monomers as well as by their relative reactivity. These compositional sequences characterize the material and allow predictions of activity based on structure by comparison with field tested polymers. 

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