subroutine forcdt(u,v,a,dp,du,time,dtime,ndag,node,
     1x4,xord,ncrv,iacflg,inc,ipass)
c
c CONTACT: ap@marc.de
c      
c* * * * * *
c
c     input of time dependent loading functions and boundary
c     conditions.
c
c     u            array of total displacements
c     v            array of total velocities
c     a            array of total accellerations
c     dp           array of incremental point loads
c     du           array of incremental displacements
c     time         time
c     dtime        time increment
c     ndag         number of degrees of freedom per node
c     node         node number
c     xord         orriginal coordinates
c     ncrv         number of coordinates
c     iacflg   acceleration flag - set to 1 if accelerations given
c     inc          increment number
c     ipass        pass number for thermo-mechanically coupled
c
c* * * * * *
      implicit real*8 (a-h,o-z)                                               dp
      dimension u(ndeg),v(ndeg),a(ndeg),dp(ndeg),du(ndeg)
      dimension xord(ncrd)
c
      include '../common/space'
      include '../common/dimen'
      include '../common/strvar'
c
      if (ipass.eq.2) return
c
      n1 = node
c
c... ints(inpbs+i-1)  = node number of BC i in BC-list
c... ints(infixs+i-1) = is the d.o.f. (1 for heat transfer)
c... ints(ionbcs+i-1) = status: 1=on; 0=off
c
c... search for this node in the BC-list.
      do 100, i1=1,numbcs
       if (ints(inpbs+i1-1).eq.n1) then
c
c... idof = degree of freedom of this BC.
        idof = ints(infixs+i1-1)
c
c... iact=1: BC is active; iact=0: BC is not active.
        iact = ints(ionbcs+i1-1)
c
c... decide if this BC remains active or not
c... the statement below switches off the BC permanently.
        dist = -5d0
        ypos = xord(2) + u(2)
        if (ypos.le.dist) ints(inpbs+i1-1) = 0
c
c       write(0,'(3i6,e15.5)') n1,idof,iact,t(idof)
       endif
 100  continue
c
      return
      end