CrisfieldTrussElement
From KratosWiki
General description
The Crisfield Truss Element is a truss element in 3D space.(Currently it is only applied in 2D, but we can change it also for 3D). For this element, both geometrial nonlinearity and material nonlinearity are considered here.
Element formulation
Element position vectors:
- current configuraton:
- reference configuraton:
Element displacement vector:
Element lengths:
- current configuraton:
- reference configuraton:
- with
, 
is a second-order unity tensor.
- with
Green-Lagrange strain:
2nd-Piola-Kirchhoff stress:
- St. Venant model:
- Scalar damage model:
Residual force vector:
-
- external force vector:
- internal force vector:
- external force vector:
Tangent stiffness matrix:
-
- material stiffness matrix:
![\mathbf{{K}^{e}_{m}}(\mathbf{u^{e}})= \tfrac{\mathrm{E}A}{L^3} \big[\mathbf{A}\cdot(\mathbf{X^{e}}+\mathbf{u^{e}})\big]\big[(\mathbf{X^{e}}+\mathbf{u^{e}})\cdot\mathbf{A}\big]](/images/math/1/6/4/16494c1432c6606312c2a21d666f994f.png)
- geomatrical stiffness matrix:
- material stiffness matrix:
How to use this element
The CrisfieldTrussElement is part of the KratosStructuralApplication and can be generated in the .elem input file using the name CrisfieldTrussElement3D2N.
