In general, a distinction is made between the following relative stiffnesses:
- Bending stiffness
- Torsional stiffness
- Shear stiffness
- Strain stiffness
Stiffness Types in RFEM
- Standard (isotropic surface)
- Without membrane tension (like Standard but failure of membrane stiffness under tension)
- Orthotropic (orthotropic surface, different stiffnesses in the x- and y-direction of finite elements)
- Glass (for surfaces made of glass, created by the RF-GLASS add-on module)
- Laminate (laminate theory, created by the RF-LAMINATE add-on module)
- Rigid (surfaces with very high stiffness)
- Membrane (surfaces with membrane stiffnesses only)
- Membrane - Orthotropic (different membrane stiffnesses in the x- and y-direction of finite elements)
- Null (surfaces will be ignored in the calculation, necessary for solids)