Skip to content

Home > List of Keywords > *GRNOCONT,NAME=LOADLOCSTIFF

*GRNOCONT,NAME=LOADLOCSTIFF

Data format:

Four lines defined as follows:

NNO
I_1 ... I_NNO
DLLFileName
DLLProcName

Status :

Optional

Restriction :

For dynamic analyses only.

Purpose :

To define loads on a set of nodes updated at every time step from a .dll file. The .dll is called at the beginning of every time step. Inside the time step, the loads are modified by adding to the loads at the entrance of the time step:

  • the stiffness matrix mulitplied by the variation of the nodal position,

  • the damping matrix times the variation of the nodal velocity,

  • the mass matrix times the variation of the nodal acceleration.

Variation is the variation between the value of the quantity while iterating in the time step and the value of the quantity entering the time step. The three matrices are used to help convergence.

Details :

Parameter Description
NNO Number of nodes
I_1 ... I_NNO List of the identification numbers of the NNO nodes
DLLFileName DLL file name
DLLProcName DLL procedure name

Note

Procedure in the DLL exchanges the following information with DeepLines at the beginning of each timestep :

( t, dt, isize, matrot, posglo, vitnode, accnode, fnoload, stiffmat, dampmat, matmat ) where

  • t : time when the dll is called (input)
  • dt : time step (input)
  • isize (=NNO): Number of nodes provided to the .dll (input to .dll)
  • matrot(9x isize ) : rotation matrix of the nodes, first line from 1 to 3, second line from 4 to 6 and third line from 7 to 9 (input) for first node and so on
  • Posglo(3x isize ) : position of the nodes (for first node and so on) in the global frame (input to .dll)
  • vitnode(6x isize ) : velocity of the nodes (for first node and so on) in the global frame (input to .dll)
  • accenode(6x isize ) : acceleration of the nodes (for first node and so on) in the global frame (input to .dll)
  • fnoload(6x isize ) : loads (force and moment) in local frame of the nodes (output from .dll)
  • stiffmat(36x isize ) : stiffness matrix of the nodes, first line of first node from 1 to 6 then second line of first node from 7 to 12, .. (output from .dll)
  • dampmat(36x isize ) : damping matrix of the nodes, first line of first node from 1 to 6 then second line of first node from 7 to 12, .. (output from .dll)
  • matmat(36x isize ) : mass matrix of the nodes, first line of first node from 1 to 6 then second line of first node from 7 to 12, .. (outputfrom .dll)