When loaded in simple shear deformation, polymeric materials may develop so-called normal stresses: stresses perpendicular to the direction of the applied shear. These normal stresses are intrinsically nonlinear: basic symmetry considerations dictate they may only enter at O(γ(2)), with γ the dimensionless shear strain. There is no fundamental restriction on their sign, and normal stresses may ...

Formulations for a general theory of thermoelasticity to generate accurate thermal stresses for structural members of aeronautical vehicles were developed in 1954 by Boley. The formulation also provides three normal stresses and a shear stress along the entire length of the beam. The Poisson effect of the lateral and transverse normal stresses on a thermally loaded beam is taken into account in...

A simple Rouse-type model, generalized to incorporate the effects of chemical cross-links, is used to obtain a theoretical prediction for the critical behavior of the normal-stress coefficients Psi(1) and Psi(2) in polymeric liquids when approaching the gelation transition from the sol side. While the exact calculation shows Psi(2) identical with 0, a typical result for these types of models, a...

background the purpose of this study was to compare the mental health and daily stress in periodontal diseases and normal group. material and methods a causal comparative method was carried out. using the screening sampling method, the sample subjects were selected from 20 patients with periodontal diseases and 20 attendants of patient as normal group. the two groups were matched from age, sex,...