3.2.16 The ELEMENT USES Data Cards

The ELEMENT USES indicator card is used to specify the names and types of the nonlinear element functions. The element types may be selected from among those defined in the ELEMENT TYPE section. Associations are made between the problem variables and the elemental variables for the elements used and parameter values are assigned. The syntax for data following this indicator card is given in Figure 3.17.

Figure 3.17: Possible data cards for ELEMENT USES

There are three sorts of data cards in the ELEMENT USES section. For cards of the second and third kinds, the string elmnt-name in data field 2 gives the name, or an array of names, of a nonlinear element function. This name may be up to ten characters long and each nonlinear element name must be unique. On array cards (those prefixed by X or Z), the expanded element array name in field 2 must be valid and the integer indices must have been defined in a parameter assignment (see Section 3.2.3).

The first kind of cards, identified by the characters T or XT in field 1, give the name, or an array of names, of an element and its type. On such cards, the string $$$$$$$$$$ in field 2 is used for two purposes.

• It may contain the name, or an array of names, of a nonlinear element function whose type is to be defined. This name may be up to ten characters long and each nonlinear element name must be unique. On XT cards the expanded element array name in field 2 must be valid and the integer indices must have been defined in a parameter assignment (see Section 3.2.3).

• It may be used to assign a default type to all the nonlinear element functions. In this case field 2 must contain the string `DEFAULT'. Any element not explicitly typed is assumed to belong to a default type. If a default is to be used, it must be specified on a card and such a card may only appear before the first T or XT card in the ELEMENT USES section. The string etype-name in data field 3 gives the name of the element type to be used. This name may be up to ten characters long and must have appeared in the ELEMENT TYPE section.

The second kind of data card, identified by the characters V or ZV in field 1, is used to assign problem variables to the elemental variables appropriate for the element type. On this data card, the string ev-nam in data field 3 gives the name of one of the elemental variables for the given element type. This name must have been set in the ELEMENT TYPE section and be a valid Fortran name (see Section 3.1.2). The string varbl-name in data field 5 then gives the name of the problem variable that is to be assigned to the specified elemental variable. The name of this variable may have been set in the VARIABLES/COLUMNS section or may be a new variable (often known as a nonlinear variable) introduced here and can be up to ten characters long. On a ZV card, the name of the variable must be an element of an array of variables, with a valid name and index.

The last kind of data card, identified by the characters P, XP or ZP in field 1, is used to assign numerical values to the parameters for the element functions (P) or array of element functions (XP and ZP). On this data card, the string ep-nam in data field 3 (and, for P and XP cards, optionally 5) must give the name of a parameter. This name must have been set in the ELEMENT TYPE section and be a valid Fortran name, see Section 3.1.2. On P and XP cards, the strings numerical-vl in data fields 4 and (optionally) 6 contain the numerical value of the parameter. These values may each occupy up to 12 locations within their field. On ZP cards, the string r-p-a-name in data field 5 gives a real parameter array name. This name must have been previously defined and its associated value then gives the numerical value of the parameter.