...
An
...
equal
...
constraint
...
is
...
applied
...
to
...
...
such
...
that
...
equal
...
displacement
...
occurs
...
along
...
the
...
translational
...
DOF
...
specified.
...
No
...
coupling
...
occurs
...
between
...
translation
...
and
...
rotation,
...
differentiating
...
an
...
equal
...
constraint
...
from
...
a
...
...
...
.
...
Equal
...
constraints
...
are
...
useful
...
for
...
modeling
...
expansion
...
joints
...
and
...
locations
...
where
...
two
...
elements
...
connect
...
to
...
form
...
a
...
slot-pin
...
connection,
...
as
...
described
...
in
...
the
...
...
...
...
...
...
...
tutorial.
...
To
...
fully
...
connect
...
...
which
...
do
...
not
...
share
...
common
...
joint
...
locations,
...
body
...
constraints
...
should
...
be
...
used,
...
rather
...
than
...
equal
...
constraints.
...
Otherwise,
...
the
...
constraint
...
may
...
restrain
...
the
...
system
...
against
...
certain
...
types
...
of
...
behavior,
...
thus
...
stiffening
...
the
...
model,
...
and
...
generating
...
unrealistic
...
moment
...
values.
...
This
...
will
...
affect
...
analysis
...
and
...
may
...
lead
...
to
...
the
...
reporting
...
of
...
a
...
lack
...
of
...
equilibrium
...
among
...
constraint
...
forces.
...
| Show if | ||
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TO DO: Migrate Body vs. equal constraint Test problem 1 from migration1d to Constraint test problems. Question 1: Why do equal constraints affect analysis when body constraints should be applied? Extended Question 1: The CSI Analysis Reference Manual] (Equal Constraint, page 59) states that equal constraints may unrealistically stiffen the structure when applied between meshes which do not share common joints. Is an explanation and an example available? Answer 1: Please refer to the |