anchor.diff:  ! This subroutine calculates elemetal internal forces
   !------------------------------------------------------------
   
  -   REAL(ReKi),     INTENT(IN   ):: Nuu0(:) ! Nodal initial position for each element !bjj: not used
      REAL(ReKi),     INTENT(IN   ):: Nuuu(:) ! Nodal displacement of Mass 1 for each element
  -   REAL(ReKi),     INTENT(IN   ):: Nrr0(:) ! Nodal rotation parameters for initial position !bjj: not used
      REAL(ReKi),     INTENT(IN   ):: Nrrr(:) ! Nodal rotation parameters for displacement of Mass 1
      REAL(ReKi),     INTENT(IN   ):: Nvvv(:) ! Nodal velocity of Mass 1: m/s for each element
      REAL(ReKi),     INTENT(IN   ):: EStif0_GL(:,:,:) ! Nodal material properties for each element
  
positive.code: 
  END SUBROUTINE BD_GenerateDynamicElementAcc
  !-----------------------------------------------------------------------------------------------------------------------------------
  SUBROUTINE BD_ElementMatrixAcc(Nuu0,Nuuu,Nrr0,Nrrr,Nvvv,&
                                 EStif0_GL,EMass0_GL,gravity,DistrLoad_GL,&
                                 ngp,gw,hhx,hpx,Jaco,uu0,E10,   &
                                 node_elem,dof_node,damp_flag,beta,&
  
negative.code:        mEta(3)      =  EMass0_GL(1,5,igp)
         rho(1:3,1:3) = EMass0_GL(4:6,4:6,igp)
         CALL BD_GaussPointDataMass(hhx(:,igp),hpx(:,igp),Jaco(igp),Nvvv,temp_Naaa,RR0,&
               node_elem,dof_node, vvv,temp_aaa,vvp,mEta,rho,ErrStat2,ErrMsg2)
            CALL SetErrStat( ErrStat2, ErrMsg2, ErrStat, ErrMsg, RoutineName )
         CALL BD_ElasticForce(E1,RR0,kapa,Stif,cet,fact,Fc,Fd,Oe,Pe,Qe,ErrStat2,ErrMsg2)
            CALL SetErrStat( ErrStat2, ErrMsg2, ErrStat, ErrMsg, RoutineName )
  