Engineering science material deformation

From strength of materials one can move two ways. On the one hand, mechanical and civil engineers and applied mathematicians shift towards more elaborate situations, such as plastic shakedown in elaborate roof trusses here some transient plastic deformation is planned for. Other problems involve very complex elastic situations. This kind of continuum mechanics is a huge field with a large literature of its own (an example is the celebrated book by Timoshenko 1934), and it has essentially nothing to do with materials science or engineering because it is not specific to any material or even family of materials. 

Figure 6.28 Schematic illustration of the piezoelectric effect that occurs in (a) an unstressed and (b) stressed piezoelectric material. Mechanical deformation can also occur when (c) a voltage is applied to a piezoelectric material. From K. M. Ralls, T. H. Courtney, and J. Wulff, Introduction to Materials Science and Engineering. Copyright 1976 by John Wiley Sons, Inc. This material is used by permission John Wiley Sons, Inc.

Yin, H., and Wei, R. P., Deformation and Subcritical Crack Growth under Static Loding, Materials Science and Engineering, A119 (1989), 51-58. 

Simultaneously, processes of plastic deformation, fracture and interactions with the environment, and counterbody can occur. The latter ones have been studied by mechanical engineers and tribologists, but the processes of phase transformations at the sharp contact have been investigated for only a few materials (primarily, semiconductors) and the data obtained so far can only be considered preliminary. One of the reasons for the lack of information may be the fact that the problem is at the interface between at least three scientific fields, that is, materials science, mechanics, and solid state physics. Thus, an interdisciplinary approach is required to solve this problem and understand how and why a nonhydrostatic (shear) stress in the two-body contact can drive phase transformations in materials. 

H. Suematsu, J. J. Petrovic and T. E. Mitchell, Plastic deformation of silicon nitride single crystals Materials Science and Engineering, A 209, 1996, 97-102. 

The purpose of this book is to present a coherent picture of the inelastic deformation and fracture of polymers from a mechanistic point of view, addressed to graduate students of material science and mechanical engineering and to professional practitioners in the field. 

This initial microcrack formation is reflected in a stress-strain curve by the deviation from the linear range of the elastic constants. In fact, the failure is analogous to the microcracks that form between spherulites when a semi-crystalline polymer is deformed. (Source Osswald, T.A. and G. Menges, Material Science of Polymers for Engineers, Hanser Publishers, New York, 1996). Refer also to Vulcanization, Peroxides, Peroxide Cross-Linking, Sulfur Vulcanization, and Vulcanizing Agents. 

Moire interferometry is used to measure tiny deformations of solid bodies, caused by mechanical forces, temperature changes, or other environmental changes [20]. It has been appUed for studies of composite materials, polycrystalline materials, layered materials, piezoelectric materials, ffacmre mechanics, biomechanics, stmctural elements and stractural joints. It is practiced extensively in the microelectronics industry to measure thermally induced deformation of electronic packages. Moire interferometry combines the simplicity of geometrical moire with the high sensitivity of optical interferometry, measuring in-plane displacements (Fig. 12.12). It is characterised by a list of excellent qualities. Moire interferometry has a proven record of applications in engineering and science. 

Fig. 1-13. Yield stress vs deformation ratio for various materials. (From Polymer Engineering and Science, 14 (10) Oct. 1974)...

Dasari, A. Rohrmann, J. Misra R.D.K. (2003). Microstructural aspects of surface deformation processes and fracture of tensile strained high isotactic polypropylene. Materials Science and Engineering A, Vol.358, (October 2003), pp. 372-383, ISSN 0921-... 

Knowledge of the deformation micromechanisms of polymers is an important aspect of the fields of materials science and engineering. Indeed, precise investigations of the processes of deformation and fracture have contributed a great deal to the construction of materials with tailored properties [87-89]. 

Lee, S.W., Choi, H.J., Kim, Y., Bae, D.H., 2007. Deformation behaviour of nanoparticle/fibre-reinforced nanocrystalline Al-matrix composites. Materials Science and Engineering 449-451, 782-785. 

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