Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Essential boundary conditions in meshfree methods via a modified variational principle: Applications to shell computations

Skatulla S., Sansour C.

Computer Assisted Mechanics and Engineering Sciences

2008

Vol. 15, No. 2

123-142

It has been recognized by many authors that the enforcement of the essential boundary conditions is not an easy task, when it comes to moving least square (MLS)-based meshfree methods. In particular, the modelling of non-linear problems requires high approximation accuracy in order to obtain a solution. This paper addresses the boundary approximation accuracy of MLS-based meshfree methods and shows more specifically its significance with respect to the imposition of essential boundary conditions by the penalty, the Lagrange multiplier method and their combination which results in a modified variational principle. The later is augmented by a stabilization term which uses individual stabilization parameters determined for each numerical integration point by an iteration procedure. This methodology is demonstrated on shell deformations in non-linear structural mechanics involving the Green strain tensor and two different hyper-elastic material laws.

A theory of the elstic-viscoplastic Cosserat continuum

Sansour C.

Archives of Mechanics

1998

Vol. 50, nr 3

577-597

Based on the multiplicative decomposition of the stretch tensor and the additive decomposition of the second Cosserat deformation tensor into elastic and inelastic parts, a theory of the elastic-viscoplastic Cosserat continuum is formulated. It is stressed that the rotation field is to be treated as a kinematical variable which can not be decomposed into elastic and inelastic parts. A thorough discussion of the configuration space by relying on basic concepts of Lie groups is provided and the field equations are derived from a variational statement. The flow rules are specified by means of the postulate of maximum dissipation paralleling some developments of the classical theory.