Listagem por temas:
Escolhendo um título você terá acesso ao arquivo original em Post-Script.
COB96 UMA TEORIA SIMPLES PARA O CÁLCULO DE TENSÕES EM VIGAS INELÁSTICAS SUBMETIDAS A CARREGAMENTOS COMPLEXOS / A SIMPLE THEORY TO PERFORM AN APPROXIMATE COMPUTATION OF THE STRESSES IN SLENDER INELASTIC MEMBERS SUBJECTED TO VARIABLE TRANSVERSE AND AXIAL LOADING
Marcio Assimos de Almeida, Heraldo S. Costtos e Marcelo Magalhães Valente
PGMEC - Depto. de Engenharia Mecânica - Universidade Federal Fluminense
Rua Passo da Pátria, 156 - Niterói/RJ CEP:24210-240
The present paper presents a simple theory to perform an approximate computation of the stresses in slender elasto-plastic and elasto-viscoplastic members subjected to variable transverse and axial loading. Theories for inelastic beams found in the literature are restricted to very simple hardening rules (generally a perfectly plastic behavior) which are not adequate to model cyclic loadings. Although the proposed theory is adequate for any kind of elasto-plastic and elasto-viscoplastic constitutive equations with internal variables , a particular set of constitutive equations which accounts for the isotropic and kinematic hardening induced by plastic deformations is considered in the presentation. No matter the non-linearity of the evolution laws adopted for the kinematic and isotropic hardening variables, simple expressions are obtained connecting the stress components with the bending moment, the shear force, the normal force and the plastic strains. The theory allows a low cost analysis of the stresses and strains in many structural elements used in industrial applications. The usefulness of the proposed theory is checked through the simulation of a combination of axial and transversal loading in 316 L stainless steel bars at 600oC
Keywords: Theory of beams, Plasticity, Viscoplasticity, Internal Variables/Teoria de vigas, Plasticidade, Viscoplasticidade, Variáveis internas.
COB449 DESCRIPTION OF THE SHAPE MEMORY EFFECT IN THE SETTING OF STANDARD GENERALIZED MATERIALS : A THREE-DIMENSIONAL MODEL
Angela C. de Souza1 , Nestor Zouain1 & Edgar Mamiya2
1 Programa de Engenharia Mecânica, Universidade Federal do Rio de Janeiro
21945-970 Rio de Janeiro, RJ - E-mail: nestor@serv.com.ufrj.br
2 Departamento de Engenharia Mecânica, FT - Universidade de Brasília
70910-900 Brasília, DF - E-mail: mamiya@enm.unb.br
A phenomenological model describing the mechanical behavior of solids undergoing stress-induced phase transformations is presented in the setting of three-dimensional media. Pseudoelasticity as well as shape memory effect can be described by the model at hand. Numerical results are presented so as to illustrate the capabilities of the three-dimensional constitutive model.
Keywords: Plasticity, pseudoelasticity, shape memory effect, martensitic transformation, constitutive model.
Fernando P. Duda & Luiz C. Martins
Programa de Engenharia Mecânica, Universidade Federal do Rio de Janeiro
21945-970 Rio de Janeiro, RJ - E-mail: duda@dserv.com.ufrj.br
A complete characterization of plane deformations with constant stretches, as well a constructive method to obtain them, is presented. With these results at hand we arrive at an important kinematical characterization of the Singh-Pipkin family of deformations. Finally, we provide a complet treatement of universal deformations with constant stretches for the Bell's elastic materials.
Keywords: Deformations with constant stretches, universal deformations, the Singh-Pipkin solution, Bell's constraint.