Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Volumetric locking

Please login with a confirmed email address before reporting spam

Hi all,

I have a question regrading the volumetric locking in using FEM with COMSOL

I plan to use linear elasticity in COMSOL for the nearly in-compressible material (ex. poisson's ratio, nu=0.49). We all know that this will result in the volumetric locking of the element without any special treatment.

As I know, ANSYS uses "Extra shape function technique" and "Reduced integration technique" in SOLID45 and SOLID185 solvers respectively to overcome the locking.

I would like to know how COMSOL treats the volumetric locking for the incompressible materials

Best wishes,

2 Replies Last Post Jun 10, 2014, 9:36 a.m. EDT
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 10, 2014, 6:50 a.m. EDT
Hi,

You select the 'Nearly incompressible material' checkbox to enable the mixed ('hybrid'; 'u-p') formulation.

Regards,
Henrik
Hi, You select the 'Nearly incompressible material' checkbox to enable the mixed ('hybrid'; 'u-p') formulation. Regards, Henrik

Nagi Elabbasi Facebook Reality Labs

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 10, 2014, 9:36 a.m. EDT
Hi Jichul,

To be precise ANSYS element SOLID45 overcomes volumetric locking via Reduced Integration not the Enhanced Strains … those are for shear locking. Reduced integration goes hand in hand with Hourglass Control. SOLID185 overcomes volumetric locking via a Mixed u-p formulation which is much more robust. That is pretty much the same approach that COMSOL uses as Henrik pointed out.

Nagi Elabbasi
Veryst Engineering
Hi Jichul, To be precise ANSYS element SOLID45 overcomes volumetric locking via Reduced Integration not the Enhanced Strains … those are for shear locking. Reduced integration goes hand in hand with Hourglass Control. SOLID185 overcomes volumetric locking via a Mixed u-p formulation which is much more robust. That is pretty much the same approach that COMSOL uses as Henrik pointed out. Nagi Elabbasi Veryst Engineering

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.