...
The
...
purpose
...
of
...
this
...
page
...
is
...
to
...
explain
...
the
...
warning
...
message
...
"Eigenvalue
...
was
...
found
...
out
...
of
...
sequence".
...
Modes
...
are
...
found
...
in
...
order
...
of
...
increasing
...
distance
...
of
...
frequency
...
from
...
the
...
shift.
...
If
...
lower
...
frequency
...
is
...
found
...
after
...
a
...
larger
...
frequency,
...
the
...
program
...
display
...
the
...
"out
...
of
...
sequence"
...
warning.
...
Please
...
note
...
that
...
this
...
is
...
a
...
warning,
...
not
...
an
...
error,
...
and
...
may
...
occur
...
if
...
the
...
structure
...
is
...
sensitive
...
to
...
instabilities.
...
A
...
structure
...
that
...
is
...
unstable
...
when
...
unloaded
...
will
...
have
...
some
...
modes
...
with
...
zero
...
frequency.
...
These
...
modes
...
may
...
correspond
...
to
...
rigid-
...
body
...
motion
...
of
...
an
...
inadequately
...
supported
...
structure,
...
or
...
to
...
mechanisms
...
that
...
may
...
be
...
present
...
within
...
the
...
structure.
...
It
...
is
...
not
...
possible
...
to
...
compute
...
the
...
static
...
response
...
of
...
such
...
a
...
structure.
...
However,
...
by
...
using
...
a
...
small
...
negative
...
shift,
...
the
...
lowest-
...
frequency
...
vibration
...
modes
...
of
...
the
...
structure,
...
including
...
the
...
zero-
...
frequency
...
in
...
stability
...
modes,
...
can
...
be
...
found.
...