Membrane

Try the following flow chart to find the best membrane element to use.

1. Is the geometry regular or irregular?

   • regular --- use quadrilateral elements

   • irregular --- use triangular elements

Triangular Elements

1. Is drilling DoF required?

   • yes --- Allman

   • no --- go to Q2

2. Prefer speed or accuracy?

   • speed --- CP3

   • accuracy --- CP6

Noting that CP3 element is very rigid and often requires a very dense mesh to get relatively accurate result, it is not recommended for most applications.

Quadrilateral Elements

1. Is drilling DoF required?

   • yes --- go to Q2

   • no --- go to Q3

2. Is consistent material stiffness available?

   • yes --- go to Q6

   • no --- GQ12

3. Used in elastoplastic applications?

   • yes --- normally mixed formulation is better, go to Q4, alternatively displacement based formulation, go to Q5

   • no --- go to Q5

4. Prefer speed or accuracy?

   • speed --- PS

   • accuracy --- QE2

5. Prefer speed or accuracy?

   • speed --- CP4I or second option CP4

   • accuracy --- CP8R or second option CP8

6. Need faster analysis?

   • yes --- SGCMQ

   • no --- GCMQ