Welcome to Adams/Solver Subroutines - Kxcad.net

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Adams/Solver
npar An integer variable that indicates the number of constants you specify in the
USER parenthetical list. This variable provides the CNFSUB evaluation
subroutine with the number of values stored in the par array.
par A double-precision array of constants taken in order from the
NORMAL_FUNCTION USER parenthetical list of the CONTACT statement.
time A double-precision variable through which Adams/Solver conveys the current
simulation time.
Output Argument
result A double-precision array that returns the value of the normal force.
Extended Definition
The IMPACT and POISSON force types in the CONTACT statement are usually sufficient to define the
contact normal force. However, if you require another force model, you can use a CNFSUB. If the
algorithms use or consist of already-existing FORTRAN-77 subroutines, CNFSUB can be made to call
them.
You can call utility subroutines, such as AKISPL, CUBSPL, SYSARY, and SYSFNC, from CNFSUB,
to obtain information about system variables, user-defined variables, and splines.
The SYSARY and SYSFNC utility subroutines set functional dependencies when the CNFSUB
argument iflag is true. To compute solutions efficiently, Adams/Solver must know the other variables on
which each user-defined variable depends. Adams/Solver determines these functional dependencies at
the beginning of the simulation by calling CNFSUB with the argument iflag set to true. Adams/Solver
does this once for each CONTACT statement with a
NORMAL_FUNCTION=USER() argument.
During each call to CNFSUB, Adams/Solver records which calls you make to SYSARY and SYSFNC.
Adams/Solver assumes that the CONTACT components depend on those Adams/Solver variables that
are accessed through SYSARY and SYSFNC.
Using the dflag variable
Only the first value in the array is used by Adams/Solver.
The use of the dflag variable is optional. Its purpose is to simply let you know that CNFSUB is being
called to evaluate a partial derivative. One of the states on which the CNFSUB depends has been
perturbed very slightly. In many situations, it is likely that major calculations in the CNFSUB are