Editing Finite Element Modelling (section)

===Construct the Final AIM File===

====For Regular Sawbone AIM Construction====

Here, we will add the bone that is close to the screw with the rest of the bone and then add the screw to make the final construct.

*Use "add_aims" to add the outside bone to the closer bone to construct the complete bone.
*Use "cl_rank_extract" to clean up any lose pieces.
*Use "write" to write the complete bone to file.
*Use "set_value" to set the value of the screw (to 90 in my case) and then do it again to set the value of the bone construct (to 127 in my case).
*Use "add_aims" to add the screw and the complete bone together.
*Use "write" to write the construct to file for viewing.

To close IPL and finish the script do the following (shown below is the last command and how to close IPL and finish the script):

<pre>
!
  /write
    -name             construct
    -filename         "construct_file
    -compress-type    bin
    -version_020      true
!
..
$!
$  write sys$output "Finished."
$  exit
[END OF FILE]
</pre>

The ".." closes IPL and the rest is just finishing the script.


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====For Position Analysis Only====

Before we actually construct the bone and screw, we need to exit IPL (using .. as shown directly above) and find the positions and dimensions of the screw and bone. Below is how it is done:

<pre>
$!                          PART II : FINDING SCREW AND BONE DIMENSIONS AND POSITION
$! ---------------------------------------------------------------------------------------------------
$!
$   aix == "$UT:D3_IO_EXAMINE.EXE"
$   PIPE AIX 'sawbone_file' | SEARCH SYS$PIPE "!> Dim"| (READ SYS$INPUT LINE ; DEFINE/JOB LINE_LOG &LINE)
$   line_sym = f$trnlnm("line_log")
$   dimxbone = f$extract(37,3,line_sym)
$   dimybone = f$extract(45,3,line_sym)
$   dimzbone = f$extract(53,3,line_sym)
$   pipe aix 'screw_file' | search sys$pipe "!> Dim"| (read sys$input line ; define/job line_log &line)
$   line_sym = f$trnlnm("line_log")
$   dimxscrew = f$extract(38,2,line_sym)
$   dimyscrew = f$extract(46,2,line_sym)
$   dimzscrew = f$extract(53,3,line_sym)
$   xpos = dimxbone/2 - dimxscrew/2 + changex
$   ypos = dimybone/2 - dimyscrew/2
$   zpos = 60
$!
</pre>

AIX is a VMS command that shows the dimensions of a file. What this section does, is look for where "!> Dim" is in the AIX file and extract a certain number of characters starting at a certain character. For example, dimxbone takes 3 characters starting from the 37th character in that line.

Then the x-, y-, and z-positions are found by looking at the dimensions of the bone and placing the screw somewhere in the x-y plane and raising a bit in the z plane.

Now start up IPL again (using $ipl_batch).

*Use "read" to read in the screw file that was created earlier.
*Use "read" to read in the bone file that was created earlier.
*Use "header" to position the screw at (xpos, ypos, zpos).
*Use "header" to position the screw at (0, 0, 0).
*Use "write" to write the new screw variable to file.
*Use "copy" to make copy of the bone file you just read.
*Use "gobj" to mask the copy of the bone file with the new screw file you just wrote. This creates bone in the shape of the screw.
*Use "subtract" to subtract the screw-shaped bone from the original bone file you read in just above. This essentially creates a sample of bone that has a hole drilled in it. 
*Use "set" on the screw and the drilled bone to set the value of the screw and bone.
*Use "add" to add the screw to the drilled bone.
*Use "write" to write the construct to file.

Then close IPL and end the file, as shown in the previous section.


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====For Angle Analysis Only====
Before we actually construct the bone and screw, we need to exit IPL (using .. as shown directly above) and find the positions and dimensions of the screw and bone. Below is how it is done:

<pre>
$!                          PART II : FINDING SCREW AND BONE DIMENSIONS AND POSITION
$! ---------------------------------------------------------------------------------------------------
$!
$   aix == "$UT:D3_IO_EXAMINE.EXE"
$   PIPE AIX 'sawbone_file' | SEARCH SYS$PIPE "!> Dim"| (READ SYS$INPUT LINE ; DEFINE/JOB LINE_LOG &LINE)
$   line_sym = f$trnlnm("line_log")
$   dimxbone = f$extract(37,3,line_sym)
$   dimybone = f$extract(45,3,line_sym)
$   dimzbone = f$extract(53,3,line_sym)
$   pipe aix 'screw_file' | search sys$pipe "!> Dim"| (read sys$input line ; define/job line_log &line)
$   line_sym = f$trnlnm("line_log")
$   dimxscrew = f$extract(38,2,line_sym)
$   dimyscrew = f$extract(46,2,line_sym)
$   dimzscrew = f$extract(53,3,line_sym)
$   xpos = dimxbone/2 - dimxscrew/2
$   ypos = dimybone/2 - dimyscrew/2 + changey
$   zpos = 122 + changez
$!
</pre>

AIX is a VMS command that shows the dimensions of a file. What this section does, is look for where "!> Dim" is in the AIX file and extract a certain number of characters starting at a certain character. For example, dimxbone takes 3 characters starting from the 37th character in that line.

Then the x-, y-, and z-positions are found so that no matter what the angle of insertion of the screw, the same point on the screw always intersect the top of the bone in the centre of the x-y plane.

Now start up IPL again (using $ipl_batch).

*Use "read" to read in the screw file that was created earlier.
*Use "read" to read in the bone file that was created earlier.
*Use "header" to position the screw at (xpos, ypos, zpos).
*Use "header" to position the screw at (0, 0, 0).
*Use "turn_3d" to rotate the screw in the y-z plane.
*Use "write" to write the rotated screw variable to file.
*Use "copy" to make copy of the bone file you just read. 
*Use "gobj" to mask the copy of the bone file with the rotated screw file you just wrote. This creates bone in the shape of the rotated screw.
*Use "subtract" to subtract the screw-shaped bone from the original bone file you read in just above. This essentially creates a sample of bone that has a hole drilled in it at an angle. 
*Use "set" on the screw and the drilled bone to set the value of the screw and bone.
*Use "add" to add the screw to the drilled bone.
*Use "write" to write the construct to file.

Then close IPL and end the file, as shown in the previous section.


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