subroutine rsurfu(h,p,tgt,dnds,x1,time,u,ciname,slname,msname,
     1                  noel,node,lclose)
		include 'aba_param.inc'
c
		character*80 ciname,slname,msname
		dimension p(3),tgt(3,2),dnds(3,2),x1(3,2),time(2)
		parameter(zero=0.d0,one=1.d0)  
c		get cylinder radius
		stime=time(2)
		if(msname(1:5)=='INNER')then
			ri=0.4d0
			drdt=one
			if(stime<=one)then
				radius=ri+drdt*stime
			elseif(stime<=2.d0)then
				radius=ri+drdt*(2.d0-stime)
			else				
				radius=ri
			endif
		else
			ri=1.8d0
			drdt=-one
			if(stime>=3.05d0)then
				radius=ri+drdt*(stime-3.05d0)
			else				
				radius=ri
			endif
		endif
c 		initialize variables 
		do k1=1,2
			do k2=1,3
				tgt(k2,k1)  = zero
				dnds(k2,k1) = zero
				p(k2)       = zero
			enddo
		enddo
c 		coordinates of point on deforming body
		x = x1(1,1)
		y = x1(2,1)
		z = x1(3,1)
c		get point on rigid cylinder		
		x2=x1(1,1)+x1(1,3)
		y2=x1(2,1)+x1(2,3)
		z2=x1(3,1)+x1(3,3)
		dx=x2-x
		dy=y2-y
		dr=sqrt(dx*dx+dy*dy)
		D=x*y2-x2*y
		disc=radius*radius*dr*dr-D*D
		if(disc==zero)then
			xcor=D*dy/(dr*dr)
			ycor=-D*dx/(dr*dr)
		elseif(disc<zero)then
			xcor=1.e6
			ycor=1.e6
			print *,'warning - perpendicular slave master normals'
		else
			x1cor=(d*dy+sign(one,dy)*dx*disc)/(dr*dr)
			x2cor=(d*dy-sign(one,dy)*dx*disc)/(dr*dr)
			y1cor=(-d*dx+abs(dy)*disc)/(dr*dr)
			y2cor=(-d*dx-abs(dy)*disc)/(dr*dr)	
			dx1=x1cor-x
			dx2=x2cor-x2
			dy1=y1cor-y
			dy2=y2cor-y2
			d1=sqrt(dx1*dx1+dy1*dy1)
			d2=sqrt(dx2*dx2+dy2*dy2)
			z1cor=x1(3,3)*d1+z
			z2cor=x1(3,3)*d2+z
			dz1=z1cor-z
			dz2=z2cor-z2
			dist1=sqrt(dx1*dx1+dy1*dy1+dz1*dz1)
			dist2=sqrt(dx2*dx2+dy2*dy2+dz2*dz2)
			if(dist1<dist2)then
			    p(1) = x1cor
				p(2) = y1cor
				p(3) = z1cor
			else
			    p(1) = x2cor
				p(2) = y2cor
				p(3) = z2cor			
			endif
		endif	
c 		project point onto unit radius cylinder
        r = ( x*x + y*y )**(0.5d0)
        x = p(1)/radius
        y = p(2)/radius
c		get unit tangents		
        tgt(1,1)  = -y
        tgt(2,1)  =  x
        tgt(3,2)  =  one
c		get local curvatures		
        dnds(1,1) = -y / radius
        dnds(2,1) =  x / radius
c		get surface penetration depth	
		if(msname(1:5)=='INNER')then
			h = radius - r
		else
			h = r - radius
		endif
      return
      end