- Frame Elements:
This element is based on Euler-Bernoulli formulation. The formulation assumes that a cross section plane orthogonal to the axis of undeformed beam will remain plane and also orthogonal to the axis in deformed configuration. This assumption is valid for thin beams where axial strains (due to the axial forces and also bending moments) are dominant. For short (or thick) beams this formulation is not recommended while it can not reproduce the shear strain of the section.
This element in Kratos is designed for small strain and in this range produce accurate results. The element does not accept any constitutive law and cannot be used for non linear materials.