General Mechanical

General Mechanical

Outputing a damping Matrix

    • nalin2021
      Subscriber

      Hi,

      I have following APDL code for a Plate supported by COMBIN14 elements I have set the damping coefficient to 1e9 for the element and in addition I have added a constant for structural damping of the plate itself. Yet when I run my code in APDL, the outputted Damping matrix "dfsi.txt" has no non-zero terms. Could anyone help?

      Best Regards,

      Nalin

       

       

      /CLE    ,START  
      /COM,ANSYS RELEASE 2022 R2           BUILD 22.2      UP20220516       12:58:27
      /input,start,ans,'C:\Program Files\ANSYS Inc\ANSYS Student\v222\ANSYS\apdl\'
      /PREP7  
      !!!!Nihilus 
      BLC4, , ,0.4,0.5
      !*  
      KL,4,0.25, ,
      !*  
      KL,4,0.5, , 
      !*  
      KL,4,0.75, ,
      !*  
      KL,2,0.25, ,
      !*  
      KL,2,0.5, , 
      !*  
      KL,2,0.75, ,
      !*  
      KL,1,1/3, , 
      !*  
      KL,1,2/3, , 
      !*  
      KL,3,2/3, , 
      !*  
      KL,3,1/3, , 
      LSTR,      13,      11  
      LSTR,      14,      12  
      LSTR,      10,       5  
      LSTR,       6,       9  
      LSTR,       8,       7  
      ASBL,       1,       5  
      ASBL,       2,       6  
      FLST,2,3,5,ORDE,3   
      FITEM,2,1   
      FITEM,2,3   
      FITEM,2,-4  
      ASBL,P51X,       7  
      FLST,2,3,5,ORDE,3   
      FITEM,2,2   
      FITEM,2,6   
      FITEM,2,8   
      ASBL,P51X,       8  
      FLST,2,3,5,ORDE,3   
      FITEM,2,1   
      FITEM,2,4   
      FITEM,2,10  
      ASBL,P51X,       9  
      !*  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,1,,206000000000  
      MPDATA,PRXY,1,,0.3 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,1,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,1,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,2,,206000000000  
      MPDATA,PRXY,2,,0.3  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,2,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,2,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,3,,206000000000  
      MPDATA,PRXY,3,,0.3  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,3,,7850 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,3,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,4,,206000000000  
      MPDATA,PRXY,4,,0.3  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,4,,7850 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,4,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,5,,206000000000  
      MPDATA,PRXY,5,,0.3  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,5,,7850 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,5,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,6,,206000000000 
      MPDATA,PRXY,6,,0.3 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,6,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,6,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,7,,206000000000  
      MPDATA,PRXY,7,,0.3
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,7,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,7,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,8,,206000000000  
      MPDATA,PRXY,8,,0.3  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,8,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,8,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,9,,206000000000  
      MPDATA,PRXY,9,,0.3 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,9,,7850 
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,9,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,10,,206000000000  
      MPDATA,PRXY,10,,0.3  
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,10,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,10,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,11,,206000000000 
      MPDATA,PRXY,11,,0.3
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,11,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,11,,1000000000

      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,EX,12,,206000000000
      MPDATA,PRXY,12,,0.3
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DENS,12,,7850
      MPTEMP,,,,,,,,  
      MPTEMP,1,0  
      MPDATA,DMPR,12,,1000000000


      !*  
      ET,1,SHELL181   
      !*  
      !*  
      !*  
      ET,81,COMBIN14  
      KEYOPT,81,2,3   
      !*  
      sect,1,shell,,  
      secdata, 0.01,1,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,2,shell,,  
      secdata, 0.01,2,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,3,shell,,  
      secdata, 0.01,3,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,4,shell,,  
      secdata, 0.01,4,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,5,shell,,  
      secdata, 0.01,5,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,6,shell,,  
      secdata, 0.01,6,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,7,shell,,  
      secdata, 0.01,7,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,8,shell,,  
      secdata, 0.01,8,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,9,shell,,  
      secdata, 0.01,9,0.0,3   
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,10,shell,, 
      secdata, 0.01,10,0.0,3  
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,11,shell,, 
      secdata, 0.01,11,0.0,3  
      secoffset,MID   
      seccontrol,,,, , , ,
      sect,12,shell,, 
      secdata, 0.01,12,0.0,3  
      secoffset,MID   
      seccontrol,,,, , , ,
      ESIZE,0.01,0,   
      CM,_Y,AREA  
      ASEL, , , ,       7 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       1, ,   1,       0,   1  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,       9 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       2, ,   1,       0,   2  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,       5 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       3, ,   1,       0,   3  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,      11 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       4, ,   1,       0,   4  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,      12 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       5, ,   1,       0,   5  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,       3 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       6, ,   1,       0,   6  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,      14 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       7, ,   1,       0,   7  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,      15 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       8, ,   1,       0,   8  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,       6 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,       9, ,   1,       0,   9  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,       8 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,      10, ,   1,       0,  10  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,      13 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,      11, ,   1,       0,  11  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      CM,_Y,AREA  
      ASEL, , , ,       2 
      CM,_Y1,AREA 
      CMSEL,S,_Y  
      !*  
      CMSEL,S,_Y1 
      AATT,      12, ,   1,       0,  12  
      CMSEL,S,_Y  
      CMDELE,_Y   
      CMDELE,_Y1  
      !*  
      MSHAPE,0,2D 
      MSHKEY,0
      !*  
      FLST,5,12,5,ORDE,6  
      FITEM,5,2   
      FITEM,5,-3  
      FITEM,5,5   
      FITEM,5,-9  
      FITEM,5,11  
      FITEM,5,-15 
      CM,_Y,AREA  
      ASEL, , , ,P51X 
      CM,_Y1,AREA 
      CHKMSH,'AREA'   
      CMSEL,S,_Y  
      !*  
      AMESH,_Y1   
      !*  
      CMDELE,_Y   
      CMDELE,_Y1  
      CMDELE,_Y2  
      !*  
      N, 3000, 0, 0.0576923076923, 0.02   
      N, 3001, 0.4, 0.0576923076923, 0.02 
      N, 3002, 0, 0.432692307692, 0.02
      N, 3003, 0.4, 0.432692307692, 0.02  
      D, 3000, UZ ,,,,,   
      D, 3001, UZ ,,,,,   
      D, 3002, UZ ,,,,,   
      D, 3003, UZ ,,,,,   
      R,101,0, 0, , , , ,
      R,102,0, 0, , , , ,
      R,103,0, 0, , , , ,
      R,104,0, 0, , , , ,
      RMORE, ,
      !*  
      type, 81
      real, 101   
      en, 3000, 3000, 1053
      type, 81
      real, 102   
      en, 3001, 3001, 22  
      type, 81
      real, 103   
      en, 3002, 3002, 831 
      type, 81
      real, 104   
      en, 3003, 3003, 428 
      !*  
      ET,82,MASS21
      !*  
      KEYOPT,82,1,0   
      KEYOPT,82,2,1   
      KEYOPT,82,3,2   
      !*


      !*  
      R,105,0.031,
      !*   
      TYPE,  82   
      REAL,     105   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     810

      !*  
      R,106,0.031,
      !*  
      TYPE,  82   
      REAL,     106   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     796

      !*  
      R,107,0.031,
      !*  
      TYPE,  82   
      REAL,     107   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     434


      !*  
      R,108,0.031,
      !*  
      TYPE,  82   
      REAL,     108   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*    
      E,     421

      !*  
      R,109,0.031,
      !*  
      TYPE,  82   
      REAL,     109   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*    
      E,     824

      !*  
      R,110,0.031,
      !*  
      TYPE,  82   
      REAL,     110 
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*    
      E,     797

      !*  
      R,111,0.031,
      !*  
      TYPE,  82   
      REAL,     111  
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*    
      E,     225

      !*  
      R,112,0.031,
      !*   
      TYPE,  82   
      REAL,     112   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     212

      !*  
      R,113,0.031,
      !*   
      TYPE,  82   
      REAL,     113   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1411 

      !*  
      R,114,0.031,
      !*   
      TYPE,  82   
      REAL,     114
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1398  

      !*  
      R,115,0.031,
      !*   
      TYPE,  82   
      REAL,     115   
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     239

      !*  
      R,116,0.031,
      !*   
      TYPE,  82   
      REAL,     116
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     211

      !*  
      R,117,0.031,
      !*   
      TYPE,  82   
      REAL,     117
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1034 

      !*  
      R,118,0.031,
      !*   
      TYPE,  82   
      REAL,     118  
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1021

      !*  
      R,119,0.031,
      !*   
      TYPE,  82   
      REAL,     119 
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     29

      !*  
      R,120,0.031,
      !*   
      TYPE,  82   
      REAL,     120
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     16

      !*  
      R,121,0.031,
      !*   
      TYPE,  82   
      REAL,     121 
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1006

      !*  
      R,122,0.031,
      !*   
      TYPE,  82   
      REAL,     122 
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1007

      !*  
      R,123,0.031,
      !*   
      TYPE,  82   
      REAL,     123
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     2 

      !*  
      R,124,0.031,
      !*   
      TYPE,  82   
      REAL,     124
      ESYS,       0   
      SECNUM, ,   
      TSHAP,LINE  
      !*  
      E,     1

      /UI,MESH,OFF
      FINISH  
      /SOL

      !*  
      ANTYPE,2
      !*  
      !*  
      MODOPT,QRDAMP,15  
      EQSLV,SPAR  
      MXPAND,0, , ,0  
      LUMPM,0 
      PSTRES,0
      !*  
      MODOPT,QRDAMP,15,0,1000, ,OFF 
      /STATUS,SOLU
      SOLVE   
      FINISH  

      *SMAT,KS,D,IMPORT,FULL,file.full,STIFF
      *export, KS, mmf, kfsi.txt

      *SMAT,MS,D,IMPORT,FULL,file.full,MASS
      *export, MS, mmf, mfsi.txt

      *SMAT,DS,D,IMPORT,FULL,file.full,DAMP
      *export, DS, mmf, dfsi.txt

      *VEC,MapForward,I,IMPORT,FULL,file.full,FORWARD
      *PRINT,MapForward,MF.txt

      *VEC,NOD,D,IMPORT,FULL,file.full,NOD2SOLV
      *PRINT,NOD,nod.txt

    • Mike Rife
      Ansys Employee

       

      Hi Nalin2021 the MAPDL Theory Guide gives the details but the QRDamp solver does not create the damping matrix per se.  It first solves the undamped system then does a correction.  Anyway you can use wrfull,1 to stop the solve process after writing the full file along with changing to the DAMP solver via the modopt command.  Then change back to the qrdamp, and turn solving back on with wrfull,0 and perform the full solve.

      Mike

       

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