Welcome to Adams/Solver Subroutines - Kxcad.net

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Adams/Solver
to the system variables have been pre-computed and stored in the program for use in the system Jacobian
when the particular constraint is involved.
When you write a UCOSUB, equations of motion are added to the set of equations Adams/Solver
generates for the standard constraint statements. You must provide the first and second derivatives of the
constraint relationship with respect to the set of variables. You must code the constraint relationship in
the implicit form. For information on implicit forms, see DIFF statement (C++ or FORTRAN).
Caution: • When selecting the displacements or the velocities of the part principal axes for the
constraint, remember that the part principal axes are not always identical to those
of the part center-of-mass marker (CM). The following list summarizes the
circumstances in which the part principal axes may differ from those of the part
center-of-mass marker.
Structure
• When the PART statement does not include the CM argument, the principal
axes default to the body coordinate system.
• Whenever the center-of-mass marker z-axis is parallel to the z-axis of the
ground reference frame at time zero, Adams/Solver permutes the internal
representation of the principal axes by 90-degree rotations to avoid an Euler
matrix singularity.
• If the IP argument in the PART statement includes products of inertia,
Adams/Solver computes the inertial representation of the principal axes so that
the products of inertia become zero.
• When specifying an IM marker, Adams/Solver computes the principal axes,
which may or may not be the axes of the CM marker.
• When the iflag argument is true, Adams sets q to zero. When you execute
Adams/Solver, computations that divide by these values result in fatal errors.
Before dividing by q values, you should check for nonzero values or ensure the
iflag argument is false.
A sample structure for UCOSUB is shown next. The comments explain how the subroutine works.
SUBROUTINE UCOSUB (ID, TIME, Q, PAR, NPAR,
& IDRSEL, IFLAG, SCALAR, ARRAY,
& XMATRX)
C
C === Type and dimension statements ===================
C
C - External variable definitions ---------
C
INTEGER ID
DOUBLE PRECISION TIME
DOUBLE PRECISION Q( 30 )
DOUBLE PRECISION PAR( * )
INTEGER NPAR