How to creat pressure load in Feap 7.5

 Please guide me if you know how to create pressure (following load) in Feap 7.5. I use BLOCk command to creat a mesh for a 1/4tube (commands below). Now I would like to introduce internal pressure but it seem to be difficult because manual of Feap for this content is brief.

Thank you in advance.

NH Nguyen.

PARAmeter

  ri = 4 ! Elements along 0X

  si = 4 ! Elements along 0Y

  ti = 6 ! Layer of elements

  Ra = 1.1  !Outer Radius

  a  = 0.71 !inner radius

  p  = atan(1.)  ! Pi/4

  Rs  = Ra*sin(0.5*p)

  Rc  = Ra*cos(0.5*p)

  as  = a*sin(0.5*p)

  ac  = a*cos(0.5*p)

  th  = 2 !thickness

      ! Blank termination record



BLOCk 1

  CARTesian  ri,si,ti ,1 ,1 ,1,10

  1  a        0.0       0.0

  2  Ra       0.0       0.0

  3  0.701*Ra 0.701*Ra  0.0

  4  0.701*a  0.701*a   0.0

  5  a        0.0       th

  6  Ra       0.0       th

  7  0.701*Ra 0.701*Ra  th

  8  0.701*a  0.701*a   th

  14 Rc       Rs        0.0  

  16 ac       as        0.0  

  19 Rc       Rs        th

  21 ac       as        th   

     ! Blank termination record



BLOCk 2

  CARTesian ri,si,ti , , ,1,10!

  1 0.701*a  0.701*a   0.0

  2 0.701*Ra 0.701*Ra  0.0

  3 0.0      Ra        0.0

  4 0.0      a         0.0

  5 0.701*a  0.701*a   th

  6 0.701*Ra 0.701*Ra  th

  7 0.0      Ra        th

  8 0.0      a         th

  14 Rs      Rc        0.0  

  16 as      ac        0.0  

  19 Rs      Rc        th

  21 as      ac        th