shape3l.f File Reference

Go to the source code of this file.

Functions/Subroutines
subroutine	shape3l (xi, xl, xsj, xs, shp, iflag)

Function/Subroutine Documentation

shape3l()

subroutine shape3l	(	real*8, intent(in)	xi,
		real*8, dimension(3,3), intent(in)	xl,
		real*8, dimension(3), intent(out)	xsj,
		real*8, dimension(3,7), intent(out)	xs,
		real*8, dimension(7,3), intent(out)	shp,
		integer, intent(in)	iflag
	)

!
!     shape functions and derivatives for a 3-node quadratic
!     isoparametric 1-D element. -1<=xi<=1
!
!     iflag=2: calculate the value of the shape functions,
!              their derivatives w.r.t. the local coordinates
!              and the Jacobian (size of tangent vector to the
!              curved line)
!
      implicit none
!
      integer i,k,iflag
!
      real*8 shp(7,3),xs(3,7),xsi(2,3),xl(3,3),sh(3),xsj(3),xi
!
      intent(in) xi,xl,iflag
!
      intent(out) xsj,xs,shp
!
!     shape functions and their glocal derivatives for an element
!     described with two local parameters and three global ones.
!
!     local derivatives of the shape functions: xi-derivative
!
      shp(1,1)=xi-0.5d0
      shp(1,2)=-2.d0*xi
      shp(1,3)=xi+0.5d0
!
!     shape functions
!
      shp(4,1)=xi*(xi-1.d0)/2.d0
      shp(4,2)=(1.d0-xi)*(1.d0+xi)
      shp(4,3)=xi*(xi+1.d0)/2.d0
!
!     computation of the local derivative of the global coordinates
!     (xs)
!
      do i=1,3
         xs(i,1)=0.d0
         do k=1,3
            xs(i,1)=xs(i,1)+xl(i,k)*shp(1,k)
         enddo
      enddo
!
!     computation of the jacobian vector
!
      xsj(1)=dsqrt(xs(1,1)**2+xs(2,1)**2+xs(3,1)**2)
!     
      return