MSC Nastran; Patran Tutorial - Rainflow Cycle Counting Video Lecture | Nastran: Basic Tutorial for Students - Design Softwares

example will be performing the stress
life analysis using rain flow cycle
counting you'll find instructions and
details about this example and the video
description below
this is actually a continuation from the
previous example of the keyhole specimen
so a lot of walls show you right now is
essentially the same let's go ahead and
start Patran or even before that in the
video description you'll find a link to
zip file make sure you have a zip file
available and extract it somewhere to
save your desktop inside of the zipper
or two files an ashtray an import file a
DAT file and add ak5 you'll be needing
these as we do the examples so here we
have Pat Ryan open let's go ahead and
create in your pattern database in the
same folder as those two files so here
it's a two RF count beam
I don't simply call this one model once
pattern is up I'll import the national
model
I get a summer house before then I see
the model here in the back if we turn on
the model cream essentially everything's
the same if we open up the materials or
rather if we open up and show the
properties for the only material we have
we see that there's a linear elastic and
a stress life constitutive model defined
if we inspect the values here we'll
notice there's one value that's off and
that is the stress range intercept
you'll notice it's missing an 8 in the
front so let's go ahead and cancel that
and actually modify that so we correct
that mistake if you recall in the
previous example we actually have to
type in every value here manually but
here it's already been done for us for
the most part so once you correct this
issue click OK and click apply to remedy
it
it's done let's jump over to our
analysis tab and click on tire model
here add an extra one year so then it
becomes RF Calvi 1 under solution type
select leaner static under solution
parameters under fatigue properties make
sure we select its stress life and as
before everything's uh left as defaults
again make sure you check on run SN
analysis click ok here under results
output format check on op2 and click all
these open forums next let's open the
sub cases here we're not interested in
the default sub case we're just
interested in untitled SC one sub case
once you select that it should have
automatically selected this load case to
click upper results and then scroll down
click fatigue life to put it here in the
output results if you wanted to lead it
click delete and just click on anyone's
even might want to add but here we just
focus on the stress on the fatigue hit
ok and click apply to confirm the change
ask me if I want to if I'm sure I want
to confirm the overwrite and click yes
the overwrite happens click Council on
your sub case select make sure we've
gone ahead and selected untitled SC one
and click default one to remove it from
the list here click on define forty load
sequences and here's what we create our
one event select the sub case on title
SC one and here at the dock file that we
had an original folder that's where you
were selected at this point a load
magnitude per the instructions or is ten
thousand and hit enter to make sure it
gets entered into this cell add a new
load sequence where this load sequence
add a new event and select this event
one which we've just created here select
event one hit apply and now we see a new
event here hit OK here ok here and go
ahead and apply to run this analysis
once done we'll go ahead and attach our
Opie to file
soin under the analysis tab click attach
output to before we we just went ahead
and manually pointed to the resolve but
since we're working in the same folder
it knows by default to fine
dopey tube with the same job name so we
can easily click apply you know
automatically find the op2 with this job
name let's jump over to results and
click on cursor window result Potts and
here click RF County one and so on
click on log of damage for now here
let's select a scalar cursor scalar and
hit apply a rather that's not the one I
actually wanted to select what I wanted
to select was marker action object
marker and notice that uh I don't
believe markers let's set up here it's
one of those few ones that has tucked
away here in the pulldown menu so create
marker vector instead of vector let's
use scalar or I've count log of damage
and hit apply notice there's a lot of
information here let's this let's turn
some of this information off right now
we've jumped into this hole known as
select results as jump into the hole
known as display attributes here's where
we could change the marker from these
triangles to actual hole or rather dots
head applying you see the update if you
want to change the size under scalar
factory change that to say point three
or point zero three I notice they're a
lot smaller right now every point of
data has a scalar value or scalar label
you can uncheck that and hit apply and
here you have it a cleaner view all the
results and right now I'll zoom into
this particular location because I know
that
or rather let me select the right result
and here I've select the log of life
repeats us a cracked on and now once I
selected this result case and the scalar
result I see that the lowest value is
five point two eight and that's if I
look at the entire model you know that
it's approximately thirty everywhere
else but the smallest life is here at
the end no to whine essentially and if
we jump back to all the results zoom in
here we see that a node element one grid
ID one we see that we have a log life of
repeats of five point two seven five
four five point three and that's what we
have here back in patran and that's how
you would go ahead and perform this
example in Patra