Download Runstream - Shell Buckling

IUTIME = control for time increment (0 or 1). IUTIME=h
0 means time increment varies during case
1 means time increment is constant during case.
Please see the examples on pp. P30-P31 and pp. P61-P63.
For most cases (except perhaps those involving creep) you
will want to set IUTIME = 1.
IUTIME = control for time increment (0 or 1). IUTIME=1
1
DTIME = time increment=h
See the discussion on pp. P30-P31. If you have a situation
in which all loads are being increased in proportion, then
it is best to set the time increment equal to the increment
of what you feel to be the most important load component of
the case. (e.g. external pressure increment). For example,
if you think a shell will collapse at about 100 psi, then
you might wish to reach 100 psi in 10-psi increments. The
time increment, DTIME, you would then set equal to 10. For
most cases, DTIME doesn't signify a real time increment; TIME
in BOSOR5 is just a convenient parameter to use for provision
of applied loads that vary nonproportionally during a case. In
cases involving creep, TIME is real time, of course.
DTIME = time increment=1.0
1.000000
TMAX = maximum time to be encountered during this case=h
As with DTIME, you associate TMAX with the most important
load component and set it equal to the largest value of that
load component that could possibly be of any interest at
all. Overestimate here. For example, if you think the
shell you are studying might collapse at 100 psi, use TMAX
of about 10000 or 100000.
TMAX = maximum time to be encountered during this case=100000.
100000.0
Next, specify the various time functions associated with
the loads on the structure. These are the fi(time) to which
the pointers, ISTEP, IDTEMP, etc. point.
NFTIME= number of different functions of time=h
For example, you may have a case involving a temperature
distribution which is constant with time and a pressure
distribution which varies linearly with time. In such a
case, NFTIME = 2, since there are two functions of time,
one function (the temperature) a constant and the other
(the pressure) a varying quantity (See example, p. P30).
NFTIME must be equal to the highest value of any of the