FEDEASLab

General > Create_Damping

Create_Damping

Purpose

setup damping matrix of structural model

Synopsis

C = Create_Damping (type,Kf,Ml,zeta,mode)

Description

CREATE_DAMPING setup damping matrix of structural model
  C = CREATE_DAMPING (TYPE,KF,ML,ZETA,MODE)
  function sets up damping matrix C according to character variable TYPE
  for a structure with free dof stiffness matrix KF and free dof lumped mass vector ML;
  the damping matrix is calibrated so that the mode numbers in row vector MODE have
  damping ratios as specified in row vector ZETA;
  the character variable TYPE should be either 'StifProp', 'Caughey' or 'Modal'
  Note: Caughey with one mode reduces to a mass proportional damping matrix and
        with two modes reduces to Rayleigh damping;
        for more than 2 modes Caughey damping works only if Ml is fully populated;
        Modal damping refers to the method of superposing modal damping matrices by
        Wilson/Penzien; reference: Chopra, Dynamics of Structures, 2nd edition, pp. 455-463

Cross-Reference Information

This function calls:

  • EigenMode determines eigenfrequencies and eigenmodes of structural model
This function is called by:
  • Add_Damping2State setup damping matrix of structural model as field of data structure STATE