Experimental stress analysis techniques

Handhook of Experimental Stress Analysis , J. Wiley, NY (1950), p 982 (Fairly comprehensive description of y-ravs technique is given) 11) K. Siegbahm, "Beta and Gamma Ray Spectroscopy , Interscience, NY (1955) 12)W.J. Price, "Nuclear Radiation Detection ,... 

The stress distribution in HOD films was studied in Ref. [353] by polarized confocal micro-Raman spectroscopy using a 514.5-nm Ar ion laser. The process conditions for the HOD films are listed in Table H.4, and the SEM image is shown in Figure 11.44. This paper is so comprehensive, and includes a number of relevant references so that the readers are recommended to read it to know the details of the experimental and analysis techniques. The results obtained are listed below ... 

Common techniques for experimental stress analysis are as follows, in descending order of the resolution and quantity of data they yield ... 

Strain birefringence - bi-ri- frin-j9n(t)s n. Double refraction in a transparent material subjected to stress and accompanying strain. One of the techniques of experimental stress analysis is based on this phenomenon. 

Peters WH, Ranson WF (1982) Digital imaging techniques in experimental stress analysis. Opt Eng... 

The photoelastic method for experimental stress analysis is very popular among design engineers and failure analysts and has proved to be an extremely versatile, yet simple, technique. 

Table 10.32 is a shortlist of the characteristics of the ideal polymer/additive analysis technique. It is hoped that the ideal method of the future will be a reliable, cost-effective, qualitative and quantitative, in-polymer additive analysis technique. It may be useful to briefly compare the two general approaches to additive analysis, namely conventional and in-polymer methods. The classical methods range from inexpensive to expensive in terms of equipment they are well established and subject to continuous evolution and their strengths and deficiencies are well documented. We stressed the hyphenated methods for qualitative analysis and the dissolution methods for quantitative analysis. Lattimer and Harris [130] concluded in 1989 that there was no clear advantage for direct analysis (of rubbers) over extract analysis. Despite many instrumental advances in the last decade, this conclusion still largely holds true today. Direct analysis is experimentally somewhat faster and easier, but tends to require greater interpretative difficulties. Direct analysis avoids such common extraction difficulties as ... 

The aim of the present book is to offer a comprehensive, up-to-date survey of the numerous facets of the subject. As it falls in the Applied Physics series, the book focuses especially on basic chemical and physical concepts. We have, as much as possible, stressed clarity over completeness, even avoiding some obscuring aspects that, although important, might be too specialized and discourage the reader. In that case, of course, the references help the reader who needs more detailed information to find it easily. On the other hand, all the experimental aspects, original techniques, and specific methods of synthesis, measurement, control, and analysis have been developed thoroughly. 

Chemical mixture experiments have distinct characteristics that can preclude the use of traditional statistical analysis techniques. Mixture experimentation often poses unique exploratory questions that can be answered efficiently and economically with non-traditional statistical techniques. General statistical guidelines stress the importance of design, preliminary studies, action levels of variables, graphics, and appropriate statistical testing. Fractional ctorial and Simplex designs are just two of many statistical tools that are useful for analyses of mixture experiments. 

The role of structural engineers is to determine stresses and stress distributions within members that are subjected to well-defined loads. This may be accomplished by experimental testing techniques and/or by theoretical and mathematical stress analyses. These topics are treated in traditional texts on stress analysis and strength of materials. 

Emphasis has already been placed on the different experimental methodologies, for instance by Hume-Rothery et al. (1953) who stressed the need to use different complementary techniques in the definition of ternary or more complex systems. The necessity of combining thermal analysis with microscopic techniques was especially highlighted, for example, in the determination of solid liquid equilibria. 

The compaction properties of pharmaceutical formulations can be studied experimentally using a variety of techniques, ranging from instrumented production presses to compaction simulators, and methods of analysis. The results are usually plotted as porosity-axial stress functions, which is of interest to compare different materials. However, there are some drawbacks on this type of evaluation. As mentioned by Cunningham et al. [20], this approach is deficient once it considers only the average stress along the direction of compaction, ignoring radial stress transmission and friction. 

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