SD: Remove the misleading CBMod input

docs/source/user/subdyn/input_files.rst

@@ -229,13 +229,6 @@ static gravity and buoyancy loads, and high-frequency loads transferred
 from the turbine. Recommended to set to True.
 
 
-**GuyanLoadCorrection** is a flag to specify whether the extra moment due to 
-the lever arm from the Guyan deflection of the structure is to be added to the loads
-passed to SubDyn, and, whether the FEM representation should be expressed in the rotating 
-frame in the floating case (the rotation is induced by the rigid body Guyan modes).
-See section :numref:`SD_Loads` for details. Recommended to set to True.
-
-
 FEA and Craig-Bampton Parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -257,12 +250,11 @@ recommend using **NDiv** > 1 when modeling tapered members.
 should be carried out by the module. If FALSE, then the full
 finite-element model is retained and **Nmodes** is ignored.
 
-**Nmodes** sets the number of internal C-B modal DOFs to retain in the
+**Nmodes** sets the number of internal C-B modal DOF to retain in the
 C-B reduction. **Nmodes** = 0 corresponds to a Guyan (static)
-reduction. **Nmodes** is ignored if **CBMod** is set to FALSE,
-meaning the full finite-element model is retained by keeping all modes
-(i.e. a modal analysis is still done, and all the modes are used as DOFs)  .
-
+reduction. With **Nmodes** < 0 (equivalent to **CBMod** set to FALSE 
+in previous versions), SubDyn will retain all C-B modes, leading to the 
+same number of DOF as the full finite-element model.
 
 **JDampings** specifies value(s) of damping coefficients as a
 percentage of critical damping for the retained C-B modes. Distinct

docs/source/user/subdyn/theory.rst

@@ -1780,7 +1780,7 @@ Corrections to the baseline formulation ("GuyanLoadCorrection")
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The baseline FEM implementation needs to be corrected to account for the fact that loads are provided to SubDyn at the displaced positions, and to account for the rigid body motions in the floating case.
-The corrections are activated by setting the parameter **GuyanLoadCorrection** to True.
+In previous versions of SubDyn, the corrections are activated by setting the parameter **GuyanLoadCorrection** to True. This input parameter has been removed from the SubDyn primary input file, and the load corrections will always be used in current and future versions of SubDyn.
 
 
 

modules/subdyn/src/SubDyn.f90

@@ -1015,21 +1015,22 @@ SUBROUTINE SD_Input(SDInputFile, Init, p, ErrStat,ErrMsg)
 CALL ReadCom  ( UnIn, SDInputFile, ' FEA and CRAIG-BAMPTON PARAMETERS ', ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
 CALL ReadIVar ( UnIn, SDInputFile, Init%FEMMod, 'FEMMod', 'FEM analysis mode'             ,ErrStat2, ErrMsg2, UnEc ); if(Failed()) return ! 0= Euler-Bernoulli(E-B); 1=Tapered E-B; 2= Timoshenko; 3= tapered Timoshenko
 CALL ReadIVar ( UnIn, SDInputFile, Init%NDiv  , 'NDiv'  , 'Number of divisions per member',ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
-CALL ReadLVar ( UnIn, SDInputFile, Init%CBMod , 'CBMod' , 'C-B mod flag'                  ,ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
 
 IF (Check( (p%IntMethod < 1) .OR.(p%IntMethod > 4)     , 'IntMethod must be 1 through 4.')) return
 IF (Check( (Init%FEMMod < 0 ) .OR. ( Init%FEMMod > 4 ) , 'FEMMod must be 0, 1, 2, or 3.')) return
 IF (Check( Init%NDiv < 1                               , 'NDiv must be a positive integer')) return
 IF (Check( Init%FEMMod==2  , 'FEMMod = 2 (tapered Euler-Bernoulli) not implemented')) return
 IF (Check( Init%FEMMod==4  , 'FEMMod = 4 (tapered Timoshenko) not implemented')) return
 
+! Nmodes - Number of internal modes to retain. Retain all modes if Nmodes<0.
+CALL ReadIVar ( UnIn, SDInputFile, p%nDOFM, 'Nmodes', 'Number of internal modes',ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
+IF ( p%nDOFM >= 0 ) THEN
+   Init%CBMod = .TRUE.
+ELSE
+   Init%CBMod = .FALSE.
+ENDIF
 IF (Init%CBMod) THEN
-   ! Nmodes - Number of interal modes to retain.
-   CALL ReadIVar ( UnIn, SDInputFile, p%nDOFM, 'Nmodes', 'Number of internal modes',ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
-
-   IF (Check( p%nDOFM < 0 , 'Nmodes must be a non-negative integer.')) return
-
-   if ( p%nDOFM > 0 ) THEN
+   IF ( p%nDOFM > 0 ) THEN
       ! Damping ratios for retained modes
       CALL AllocAry(Init%JDampings, p%nDOFM, 'JDamping', ErrStat2, ErrMsg2) ; if(Failed()) return
       Init%JDampings=WrongNo !Initialize
@@ -1054,12 +1055,9 @@ SUBROUTINE SD_Input(SDInputFile, Init, p, ErrStat,ErrMsg)
    ELSE
       CALL ReadCom( UnIn, SDInputFile, 'JDamping', ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
    END IF
-
 ELSE   !CBMOD=FALSE  : all modes are retained, not sure how many they are yet
    !note at this stage I do not know nDOFL yet; Nmodes will be updated later for the FULL FEM CASE. 
    p%nDOFM = -1
-   !Ignore next line
-   CALL ReadCom( UnIn, SDInputFile, 'Nmodes', ErrStat2, ErrMsg2, UnEc ); if(Failed()) return
    !Read 1 damping value for all modes
    CALL AllocAry(Init%JDampings, 1, 'JDamping', ErrStat2, ErrMsg2) ; if(Failed()) return
    CALL ReadVar ( UnIn, SDInputFile, Init%JDampings(1), 'JDampings', 'Damping ratio',ErrStat2, ErrMsg2, UnEc ); if(Failed()) return