Control values

The FEAP [title] record is typically the first line in an input file. After the control word FEAP one can provide an optional text string to define the title of the problem, which is subsequently used in the output file. On the record after the keyword one defines the parameters of the problem:

1. numnp - number of nodal points (optional, FEAP will compute for you if input as zero)
2. numel - number of elements (optional, FEAP will compute for you if input as zero)
3. nummat - number of material property sets (optional, FEAP will compute for you if input as zero)
4. ndm - space dimension of the mesh (required, is arbitrary)
5. ndf - maximum number of degrees of freedom on any single node in the mesh (required, is arbitrary)
6. nen - maximum number of nodes on any single element in the mesh (required, is arbitrary)
7. nad - requested increase in element array sizes to ndf x nen + nad (optional, defaults to zero)
8. npd - requested size of material property array d(*) in elements (optional, defaults to 350 in version 8.6)
9. nud - requested size of user material property array ud(*) for user materials (optional, defaults to 150 in version 8.6)

When specifying the control values there are two options. Option one is just to list the numbers in order on the line after FEAP [title], and if you want FEAP to compute the optional values/use defaults, then you can use zeros, or if the optional values are at the end of the line just leave them off as FEAP will assume zeros and then use defaults. For example in a mesh in 3D space with 3 dofs per node and 6 nodes per element and 200 user material parameters, one could use

FEAP * * Test problem * *
0 0 0 3 3 6 0 0 200

An alternate is to use keyword pairs

FEAP * * Test problem * *
ndm = 3
ndf = 3
nen = 6
nud = 200

In this format, any unspecified control values are assumed to be zero, leading to the use of default values. Each keyword has two options (in version 8.6) as follows:

• numnp or node
• numel or elem
• numma or mate
• ndm or dime
• ndf or dofs
• nen or elno
• nad or add
• npd or prop
• nud or upro

If you use the optional version of the keywords then letters after the 4th letter are ignored so NODE and NODEs are the same as are DIME and DIMEnsions, et cetera.