FEDEASLab

Geometry > kg_QuadMemb

kg_QuadMemb

Purpose

geometric stiffness matrix for quadrilateral membrane element for different options

Synopsis

kg = kg_QuadMemb (option,xyz,u,pl)

Description

KG_QUADMEMB geometric stiffness matrix for quadrilateral membrane element for different options
  KG = KG_QUADMEMB (OPTION,XYZ,U,PL);
  the function determines the geometric stiffness matrix KG of a quad mebrane element
  with end coordinates in array XYZ (columns correspond to nodes);
  the geometric stiffness matrix depends on the node displacement values in array U (ndm x nen)
  in the global reference system and on the local nodal force vector PL; (nen = number of nodes)
  OPTION is a character variable with value equal to
  'linear' or 'corotational' for linear and corotational geometry, resp.

Cross-Reference Information

This function calls:

  • DefGeom_Quad determines local coordinates and corotational triad of quadrilateral element
  • spinblk determine the spin tensors for a group of vectors
This function is called by:
  • Inel4to9nodeQuad isoparametric 4-9 node quadrilateral element with inelastic material
  • Inel4to9nodeReQuad isoparametric 4-9 node quad element with inelastic material and reinforcing layers
  • LE4nodeQuad isoparametric 4-node quadrilateral element with linear elastic material
  • LE4nodeQuadwIM isoparametric 4-node quad element with linear elastic material and incompatible bending modes
  • LE4to9nodeQuad isoparametric 4-9 node quadrilateral element with linear elastic material
  • LE9nodeQuad isoparametric 9 node quadrilateral element with linear elastic material