رساله
خطيرة في الايتابس ومش عارف اعملها اية ارجوا الافادة
* * * w a r n i n g * * *
the structure is unstable or ill-conditioned !!
Check the structure carefully for:
- inadequate support conditions, or
- one or more internal mechanisms, or
- zero or negative stiffness properties, or
- extremely large stiffness properties, or
- buckling under p-delta loads (if any), or
- an eigen shift (if any) onto a natural frequency