A triangular finite element with local remeshing for the large strain analysis of axisymmetric solids

CASTELLÓ WALTER; FLORES FERNANDO G.

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2008 vol. 198 p. 332 - 343

0045-7825

In this work a three-node triangular finite element with two degrees offreedom per node for the large strain elasto-plastic analysis ofaxisymmetric solids is presented. The formulation resorts to the adjacentelements to obtain a quadratic interpolation of the geometry over a patch offour elements from which an average deformation gradient is defined. Thusthe element formulation falls within the framework of assumed strainelements or more precisely of F-bar type formulations. The in-planebehavior of the element is similar to the linear strain triangle, butwithout the drawbacks of the quadratic triangle, e.g. contact or distortionsensitivity. The element does not suffer of volumetric locking in problemswith isochoric plastic flow and the implementation is simple. It has beenimplemented in a finite element code with explicit time integration of themomentum equations and tools that allow the simulation of industrialprocesses. The widely accepted multiplicative decomposition of thedeformation gradient in elastic and plastic components is adopted here. Anisotropic material with non-linear isotropic hardening has been considered.Two versions of the element have been implemented based on a Total and anUpdated Lagrangian Formulation respectively. Some approximations have beenconsidered in the latter formulation aimed to reduce the number ofoperations in order to increase numerical efficiency. To consider bulkforming, with large geometric changes, an automatic local remeshing strategyhas been developed. Several examples are considered to assess the elementperformance with and without remeshing.