Plastic flow equations for the local strain approach in the multiaxial case

This paper presents a system of plastic flow equations which uses and generalizes to the multiaxial case a number of concepts commonly employed in the so-called Local Strain Approach to low cycle fatigue. Everything is built upon the idea of distance between stress points. It is believed that this w...

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Detalhes bibliográficos
Autores: Madrigal Sánchez, Carmen, Navarro Pintado, Carlos, Vallellano Martín, Carpóforo
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:España
Recursos:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/98118
Acesso em linha:https://hdl.handle.net/11441/98118
https://doi.org/10.3221/IGF-ESIS.37.02
Access Level:acceso abierto
Palavra-chave:Low cycle fatigue
Plastic Flow Rule
Kinematic Hardening
Non-proportional Loading
Multiaxial Fatigue
Descrição
Resumo:This paper presents a system of plastic flow equations which uses and generalizes to the multiaxial case a number of concepts commonly employed in the so-called Local Strain Approach to low cycle fatigue. Everything is built upon the idea of distance between stress points. It is believed that this will ease the generalization to the multiaxial case of the intuitive methods used in low cycle fatigue calculations, based on hysteresis loops, Ramberg?Osgood equations, Neuber or ESED rule, etc. It is proposed that the stress space is endowed with a quadratic metric whose structure is embedded in the yield criterion. Considerations of initial isotropy of the material and of the null influence of the hydrostatic stress upon yielding leads to the realization of the simplest metric, which is associated with the von Mises yield criterion. The use of the strain?hardening hypothesis leads in natural way to a normal flow rule and this establishes a linear relationship between the plastic strain increment and the stress increment.