Stress resultant based elasto-viscoplastic thick shell model

Article type: Research Article

Authors: Woelke, Pawel | Chan, Ka-Kin | Daddazio, Raymond | Abboud, Najib

Affiliations: Weidlinger Associates, New York, NY, USA

Note: [] Corresponding author. Tel.: +1 212 367 2983, ext: 3000; Fax: +1 212 497 2483; E-mail: woelke@wai.com; chan@wai.com

Abstract: The current paper presents enhancement introduced to the elasto-viscoplastic shell formulation, which serves as a theoretical base for the finite element code EPSA (Elasto-Plastic Shell Analysis) [1–3]. The shell equations used in EPSA are modified to account for transverse shear deformation, which is important in the analysis of thick plates and shells, as well as composite laminates. Transverse shear forces calculated from transverse shear strains are introduced into a rate-dependent yield function, which is similar to Iliushin's yield surface expressed in terms of stress resultants and stress couples [12]. The hardening rule defined by Bieniek and Funaro [4], which allows for representation of the Bauschinger effect on a moment-curvature plane, was previously adopted in EPSA and is used here in the same form. Viscoplastic strain rates are calculated, taking into account the transverse shears. Only non-layered shells are considered in this work.

Keywords: Thick plates and shells, transverse shear deformation, elasto-viscoplastic analysis, rate dependent response

DOI: 10.3233/SAV-2011-0644

Journal: Shock and Vibration, vol. 19, no. 3, pp. 477-492, 2012