Finite Element Input Files

FINITE ELEMENT INPUT FILES

ALADDIN supports the specification and solution of problems involving matrix and finite element computations. Finite element problems require the development of an input file having the following five-part format:

    /*
     *  ========================================================
     *  A description of the finite element problem goes here...
     *  ========================================================
     */

     ... Part [1] : Problem specification parameters.

     StartMesh();

     ... Part [2] : Generate finite element mesh. Specify section and
         material properties, external loads, and boundary conditions.

     EndMesh();

     ... Part [3] : Describe solution procedure for finite element
         problem.

     ... Part [4] : If applicable, check performance of structure
         against design rules.

     ... Part [5] : If applicable, generate arrays of output that are
         suitable for plotting (e.g. with MATLAB).

     quit;

Every ALADDIN input file should begin with a description of the file's purpose, and who wrote it.

Part 1 : The problem specification parameters allow an engineer to state whether a finite element problem will be two- or three- dimensional, the maximum number of degree of freedom per node, and the maximum number of nodes per element.

Part 2 : ALADDIN statements are written for the finite element mesh generation, for the section and material properties, the specification of external loads, boundary conditions, and for linking finite element d.o.f.

Mesh generation begins and ends with the function calls:

StartMesh() Allocates the working memory for the finite element data structures.

EndMesh() Loads the information provided in Part [2] into the finite element database.

Part 3 : The problem solving procedure usually begins with the assembly of the global stiffness matrix, external load vectors, and if applicable, assembly of a global mass matrix. The details of a numerical algorithm (e.g. newmark integration. modal analysis. optimization procedures) can be inserted here to solve a specific linear/nonlinear static/dynamic finite element problem.

Part 4 : Check performance of structure against design rules.

Part 5 : Generate arrays of formatted output suitable for plotting, for example, with MATLAB.

As always, the ALADDIN input should be terminated with the command quit .

StartMesh()	Allocates the working memory for the finite element data structures.
EndMesh()	Loads the information provided in Part [2] into the finite element database.