Stress definitions

Actually, several possibilities exist formulating the wall friction force. The natural boundary layer shear stress definition to use is the one deduced from the fundamental equilibrium boundary layer analysis. The wall shear stress is thus defined as —Om =... 

The veloeity gradient is essential in analyzing path dependent materials such as plastic deformation of cold-compression programmed SMP. It is also useful in determining the energetically conjugate stress and strain, as will be demonstrated in the section on stress definition. 

In strength of materials text, it is weU known that Cauchy stress, small strain because the area in the undeformed body and deformed body is almost the same. For a large strain, however, we generally do not know the area of the deformed configuration. Thus we need to define a stress measure that we can use in the reference configuration. However, it is noted that Cauchy stress is still the most used stress definition or tme stress because the equilibrium is about the deformed body but not the undeformed body. Therefore, other definitions of stress are for convenience of mathematical operation. Stress is generally reported as the Cauchy stress. This shows a distinct departure from the strain definitions. 

Stress Definition in Solid Mechanics Multiplicative Decomposition of Deformation Gradient Constitutive Modeling of Cold-Compression Programmed Thermosetting SMP... 

An additional difficulty arises when one tries to define the stress in tube models. Indeed, since the forces were not defined in the equation of motion, one carmot use the miaoscopic stress definition (eqn [ 1 ]). Thus, one has to make an additional assumption about the stress tensor expression as a function of the tube coordinates. The tube theory routinely uses an expression... 

Figure 19 Different stress definitions used in two tube models pure reptation and reputation + CLF for Z= 16. Two limiting cases are considered ...

Stress Stress definition Sources of stress Mean stress, maximum stress, minimum stress, constant load/constant strain, strain rate, plane stress/plane strain, modes 1, II, III, biaxial, cyclic frequency, wave shape Intentional, residual, produced by reacted products, thermal cycling... 

Although normal and shear stresses are the same in both tensorial and engineering stress definitions, for strains, the tensorial shear strain components ,7, where i j, represent half of the corresponding engineering strains (6,7 =... 

Two concepts are necessary to describe the stress factor (1) the stress definition with all its components and (2) the origin of the stresses, which can he external or internal, such as the wedge action of corrosion products. 

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