Large deformation rheology

Large Deformation Rheological Testing of Milk Fat and Butter... 

Genovese, D. B., Acquarone, V. M., Youn, K.-S., and Rao, M. A. 2004. Influence of fructose and sucrose on small and large deformation rheological behavior of heated Amioca starch dispersions. Food Sci. Technol. Int. 10(1) 51-57. 

Pugnaloni, L.A., Ettelaie, R., and Dickinson, E. Computer simulation of interfacial structure and large-deformation rheology during competitive adsorption of proteins and surfactants. Food Colloids Interactions, Microstructure and Processing, E. Dickinson, ed.. Royal Society of Chemistry, Cambridge, U.K., 2005a, p. 131. 

The systems discussed here also have a yield stress unfortunately, results on large deformation rheology of the systems seem to be lacking. 

During penetration of the cone assembly, the cone sinks into the fat sample until the stress exerted by the increasing contact surface of the cone is balanced by the hardness of the fat (deMan, 1983). In the process, the crystal aggregate network is partially and irreversibly destroyed (Lefebvre, 1983). Cone penetrometry is a large-deformation rheological method. 

Large deformation tests, in which a solid sample is strained to well beyond its linear limit, and often to fracture, are designed to obtain a quantitative measure of a product s functionality in end use. Many large deformation tests are empirical or imitative, and do not yield fundamental rheological or fracture data. However, such tests can, with some materials, be set up and performed in such a way that fundamental information is obtained (McCarthy, 1987). 

Static and dynamic linear viscoelastic measurements are used to gain insights into the relationships between cheese structure and rheological behavior. Non-linear viscoelastic measurements have been used to a relatively small degree to measure the response of cheese to large deformations. 

Rohm, H. 1993a. Rheological behaviour of butter at large deformations. J. Text. Stud. 4, 139-155. 

For full evaluation of the flow behaviour (rheology) of structured pesticide suspension concentrates and their settling characteristics, it is necessary to carry out measurements at small and large deformations. Such investigations provide valuable information on the viscoelastic properties of the suspension and if sufficiently analysed may be... 

Chapter 3. In-plant measurement of flow behavior of fluid Foods. Using a vane-in-a-cup as a concentric cylinder system. The vane yield stress test can be used to obtain data at small- and large-deformations. Critical stress/strain from the non-linear range of a dynamic test. Relationships among rheological parameters. First normal stress difference and its prediction. 

Fig. 1 A schematic comparison between polymer melt rheology and colloid rheology, (a) In a polymer melt, atypical chain (dashed curve) is constrained by many (in reality, 10 ) other chains, here represented by small circles. This gives rise to the fruitful mean-field concept of a tube in which the chain has to move, (b) In a concentrated colloidal suspension, a typical particle (hatched) is surrounded (in 3D) by 10 neighbours. This number is too small for mean-field averaging to be meaningful, (c) Large deformations in polymer melts, such as the process (i) -(ii), involves breaking covalent bonds, and so do not ordinarily occur, (d) There are no covalent constraints on order unity deformations, such as (i)—>(ii), in a colloidal suspension...

Mechanical properties are essential attributes of soft solids, and this concerns primarily consistency during handling or eating. Moreover, physical stability often depends on these properties. Basic aspects of rheology are discussed in Section 5.1.3. This section is primarily about large deformation, including the phenomena of yielding and fracture. 

For gas-filled systems, theory has been developed for various rheological properties. The main variable is the relative density, about equal to one minus the volume fraction of gas. In most systems, the modulus roughly scales with the density squared. What occurs at large deformation depends on the properties of the cell walls buckling if they are rubberlike, yielding if they are plastic solids, and fracturing if they are rigid solids. 

Concentrated suspensions commonly display viscoelatic behavior. The viscoelastic properties can be measured by oscillatory tests (26). Comparing with steady shear measurements, oscillatory measurements are made under small deformations, at which the suspension structure is only slightly perturbed. Hence, oscillatory measurements are suitable for correlating rheological behavior with structural data and interparticle potentials, even for strongly flocculated systems that show irreversible changes when subjected to large deformations. 

Tschoegl, N. W., Rinde, J. A., and Smith, T. L. (1970a). Rheological properties of wheat flour doughs. I. Method for determining the large deformation and rupture properties in simple tension. J. Sci. Agric. 21, 65-70. 

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