Welcome to Adams/Solver Subroutines - Kxcad.net

170
Adams/Solver
Input Arguments
id An integer variable that provides the identifier of the GFORCE statement
requesting information from GFOSUB. From the identifier,
Adams/Solver automatically recognizes other information (such as the
par argument) that is available in the corresponding statement.
time A double-precision variable containing the current simulation time.
par A double-precision array of constants taken in order from the USER
parenthetical list of the GFORCE statement.
npar An integer variable that indicates the number of constants you specify in
the USER parenthetical list. This variable provides the GFOSUB
evaluation subroutine with the number of values stored in the par array.
dflag A logical variable that Adams/Solver sets to true when it calls GFOSUB
to evaluate the partial derivatives of the specified functions. Otherwise,
Adams/Solver sets the dflag argument to false.
iflag A logical variable that Adams/Solver sets to true when it needs the
functional dependency information from GFOSUB. Functional
dependencies are established with the same calls to SYSARY, and
SYSFNC that are later used to compute the values of the GFORCE
components. If the iflag argument is false, the values of the user-defined
expressions are computed.
Output Argument
result A double-precision array that returns the six values of the GFORCE
components.
Extended Definition
The GFORCE statement with a function expression is usually adequate for defining functions that
represent the three translational and three rotational vector components of a force at a point. However, if
the force and torque expressions become lengthy and awkward, you can use a GFOSUB.
You can call utility subroutines, such as AKISPL, CUBSPL, SYSARY, and SYSFNC, from GFOSUB,
to obtain information about system variables, user-defined variables, and splines.
The SYSARY and SYSFNC utility subroutines set up functional dependencies when the GFOSUB
argument iflag is true. In order for Adams/Solver to compute solutions efficiently, it must know the
Solver states on which the GFORCES depend. Adams/Solver determines these functional dependencies
at the beginning of the simulation by calling GFOSUB with the argument iflag set to true. Adams/Solver
does this once for each GFORCE statement with a FUNCTION=USER() argument. During each call to
GFOSUB, Adams/Solver records the calls you make to SYSARY and SYSFNC. Adams/Solver assumes
that the GFORCE components depend on those Adams/Solver states that are accessed through SYSARY
and SYSFNC.