code_aster now knows how to inflate balloons!

6 April 2017

by N. Lauzeral (École Centrale Nantes); T. De Soza (EDF / R&D / ERMES)

As part of Nathan Lauzeral’s internship, a new finite element of membrane was developed in code_aster.

A documented and verified element

The implemented finite element allows the modeling of membranes in large transformations for nonlinear quasi-static simulations. It supports two hyperelastic constitutive laws (Neo-Hookean type or Saint-Venant Kirchhoff), it is used with linear or quadratic elements and is fully compatible with contact-friction.
For more details on its use, see the documentation [U2.02.01] and case studies SSNS115 and SSNS116.


Future developments may concern verification of the element in non-linear dynamics - the mass matrix has been developed but not activated due to the lack of suitable test cases - as well as the taking into account of follower forces in continuation methods.
This last point is useful for the simulations of flexible cylinders for which the application of pressure yields highly non-linear calculations.

Available starting from version 13.2.12