Program: Columns
By: Ben Axelrod

   This program will find the displacements and reactions at the support of an 
axially loaded member.  This is the first program of a set of finite element modeling 
programs.  This program is great for classes like Statics, Strength of Materials, any 
Finite Element Modeling class, and other similar engineering classes.  It can even do 
statically indeterminate members.  To use, follow the main menu.  First select 
materials, then nodes, then elements, and so on.  Detailed instructions are below.

MATERIALS:
   First enter the number of different materials you have.  A material is anything 
with a different cross-section, or modulus of elasticity.  If you have a member with 
two materials in parallel (like concrete with steel rebar in it,) enter each one 
individually, as its own material.  This will be covered in more detail below.  Then 
just enter the materials modulus of elasticity and cross-sectional area.  It is 
important to remember the numbering of you materials, you will need this information 
later in the program.

NODES:
   First enter the number of nodes you have.  You should put a node every where you 
have a force acting on the column, a support, at the ends of the column, or a change in
cross section.  You should not put more than one node at the same location.  Then you 
will have to enter the coordinates of each node.  Since this program only deals with 
axial force members, the points should all be in a line.  Therefore, it only asks you 
for one coordinate of the nodes.  It is important to remember how you numbered your 
nodes.

ELEMENTS:
   The program will now ask you how many elements you have between each node.  Most 
of the time this will just be 1.  But in the example above with the concrete with rebar
in it, you now have two elements between the two nodes.  So enter 2.  Then the program 
will ask for which materials are between the two nodes.  Enter the proper material 
numbers.  

FORCES:
   First enter the number of forces you have acting on the member.  Then enter at 
which node the force acts, and in what direction.  You should enter the force as 
negative if it is compressive.  

CONSTRAINTS:
   First enter the number of constraints you have.  This program can even do 
statically indeterminate members.  Enter the node that the constraint is at and then 
enter the amount that that node can move.  Most of the time this will be 0 for a fixed 
support.  But if you have some problem where the end of the column can only move a 
specified amount, enter it there.  

SOLVE:
   Once you have completed all of the steps above, this will solve the problem.  The 
nodal displacements are saved in the list DISPL and the reactions at the supports are 
saved in the list REACT.  To access these lists, press [2nd], [STAT].  The 
displacements and reactions are listed in the order of the node numbering.  (node1, 
node2, node3, )  After the solution is complete, the program exits.  The matrices used
for the program are not deleted.  This way you can reenter the program, change some 
parameters, and re-solve the system.  There are instructions below on reentering data.

EXIT:
   You can either choose to SAVE AND EXIT, or to CLEAR AND EXIT, or to go back to the 
main menu.  Clear and exit deletes matrices A through G and deletes the DISPL and REACT
lists.  Save and exit, quits the program without clearing the matrices used by the 
program.  Important, if you quit the program and wish to reenter it to solve the system
later.  You must not save any values to the real numbers (A through Z).  This might 
cause the program to screw up.

NOTE:
   All numberings in this program start with the number 1.  (You cant have a node 0) 
If you mess up entering your data, you can always go back and reenter it.  However, if 
you have moved on to the next entry in the main menu, you should redo that one too.  
(If you messed up with your nodes, and have already moved on to elements and forces.  
You should redo nodes, elements and forces.)   

If you have any questions or comments, please email me at: bmaxelro@syr.edu
