MSC Nastran; Patran Tutorial - Direct Transient Response; Solids and Cylindrical

in this video I will be performing a
direct transient response analysis using
solid elements and cylindrical
coordinates full details of this
exercise from on page four 10 of the PDF
linked in the video description below
offers start a new patron session the
units for this exercise are in inches
pounds in psi I'll be defining a new
cylindrical coin and system like after I
create my patron file called prop 19
click OK here and I'll jump to the
geometry tab to create my coordinate
system here we're using cylindrical the
origin would be 0 0 0 the point on the
axis 3 will be 0 1 0 and then the point
on the 1/3 plane will be 1 0 0 there's
my new coordinate system I'll create a
surface using the XYZ method from point
six zero zero I'll make a surface that
goes six inches in the X 8 inches and
the wine zero on the Z so hit enter or
apply there's my new surface I'll then
go ahead and mesh this so I go to the
meshing tab create a uniform seed I'll
be giving a requirement of eight
elements for these two edges here and
note that I've selected the etch icon
here so allows me to select the edges of
the surface for the top and bottom
surface or edges I give it a requirement
of six elements and I simply drag and
select and since I have auto execute on
automatically give it the mesh seed I
could then use the surface measure here
select this surface here make sure the
cursor is here
surface one has been selected hit apply
now it's been mashed now to make this
three-dimensional we want to go ahead
and sweep it up about the Y so here on
your FEM actions that can select sweep
when we rotate this about the Y we want
it to create three elements we want it
to use this coordinate system 0 here X Y
Z 1 we wanted to rotate about the why
right now porn in system 0 3 means that
this will be rotated like that and we
don't want that and Sorbo Taylor or be
swept like that I want them to be
rotated about the Y so here I can simply
delete the 392 alternatively have these
icons here so I can simply select the
frame Direction 3 2 or 1 and it will
automatically change it to 3 2 or 1
whichever one I've selected here but
here I know I want to
so after I select the frame Direction 2
and select this coordinate system I get
0.2 my sweep angle is 30 degrees I do
want the quad 4 elements to be deleted
after I sweep this my base entity list
will be all of these elements so I can
simply hit pick all after I click apply
you'll notice my new mesh here so now I
can continue with an example or actually
before that I have to make sure that all
the nodes are in the right coordinate
system so right now if I do a quick
examination of the finite elements so I
go to action show no location I pick a
few nodes right now I swim this one and
that one my reference analysis queerness
number the rectangular one I actually
want to use the cylindrical coordinate
system here so what I have to do is go
to action modify I want to modify my
notes and I'm on to edit as a method
Chuck analysis and reference simply drop
your cursor in here and simply select
these this coordinate system we want
this cell pi it's at every node so
simply pick all so all 252 nodes at
apply now we have the feedback a moment
ago that uh 252 notes I've been modified
so we can continue now so under
properties I can define my material call
this one matte under input properties
give it a Young's modulus of 36 psi and
Poisson ratio of 0 my density is point
zero zero zero seven to $4.99 click OK
and apply here under 3d properties
select solid call this prop under input
properties I want to use this solid or
this material and I wish to apply it to
all these elements so here I'll select
the solid element so that if I have a
wedge or hex element so I'll select and
no matter what it is so here I'll pick
all or you can individually pick the
ones you want like at ok and apply so
now the material has been applied to the
these finite elements I can now move on
to my load and be sees offers creative
field so here under LBC fields click on
non-spatial ok we'll just call it a load
or load history our load history is time
dependent so make sure that's checked on
your input data we what we want to do
here is model this load history here so
at 0 at 0 at 3:00 at 0 at 4 seconds it
actually goes up by one and up to 10
that's why
so here that that's what I'll be
entering so at 0 and at 3 e to the
negative six and this is a my or 3e to
negative six at three microseconds the
next one would be four microseconds and
these are actually in seconds we know at
zero is plane zero we know that the next
one it's zero we know at four it's one
and we know it's one at the end click OK
and here you'll notice that the apply
button out there if I move this around
here somewhere I play with it you'll you
should be able to see the apply button
if not what you can do is just put the
cursor in here and hit enter and you'll
notice I hear the feedback is the load
history has been created one thing I
have to do is create a new load case or
modify my current load case so it's a
time dependent right now my my default
load case like in every example I've
done the type is static we have to make
this time dependent so instead of
creating a new one and switching it to
time dependent
I'll just modify this one so here so
like modify select this default sub case
can minimize this I'm gonna make this
current let's switch this to time
dependent and click apply so now I can
define my loads that are time dependent
so let me first go ahead and define my
eye pressure since it's time dependent
and I'll use the load history we just
created click pressure here call this
pressure for our target element type
these are three DS so just leave a 3d or
under input data
happen when not 110 psi under load
history simply click this field we
created a few moments ago click OK
for your application region
I'll be applying this to the femme in
here where you can do is a go one by one
and so like the various phases and we're
only selecting these ones by the way and
I might get it a little bit too tedious
there are a few ways you can do this and
I'll show you how to do that
may not be obvious at first so one way
is like this let me turn on the shading
so you can see we have direct vo this
here and this is the left side view what
I can do is select visible entities only
you'll get a message here you can read
it on your own so then all I have to do
is drag window and select these faces
and add and now the convenience of this
is that when I do this it does not
select anything on the back so you see
it's still on but have this off and I
did the same thing again it would select
the faces on the back too and everything
in between and we don't want that so
just to demonstrate that again turn this
on and get a message drag and select and
select these internal ones another way
is if you go to auto select this tools
convenient for when you have various
faces are really odd here I can select
or just a demo something real quick
I can select this face here over right
and I'll select everything here based on
the defaults can add it here and do the
same for the next one over right Council
add auto select again it's like this one
override it Council and dad so now I've
done the same operation it's tedious
here but you can use this for when you
have models with a very difficult to the
pieces to select and now that I've
selected those I can click OK and click
apply to apply your pressure now I can
define my boundaries or my displacement
constraints so the first one I will call
it hoop symmetry
your input data you want to restrain
motion in the hoop direction so here one
is left blank 2 as a 0 & 3 as a blank
and one thing I forgot to do there is
use the cylindrical coordinate system so
make sure this is chord 1 click OK your
application region we want to apply this
to the nodes here and here so what we
can do here is go back to the left side
view automatically or drag a window and
select these nodes at it rotate this so
you get eyes and view of these nodes you
notice I did not select this one we add
it again and the reason is because I
still have visible entities only on so
it's only selected the ones that were
immediately visible to me let me turn
that off and we do this so now you see
it's like that these nodes add it rotate
this a little bit more select these
nodes add it now you see how both sides
selected you can see if i zoom up the
hoop Direction is constrained and you'll
know that I'm using coordinate system
one which is this one let me actually
turn on the model trace hook and turn
off these uh boundary conditions now
I've to define my axial condition here
so let's make a new one called axial
symmetry under EMPA data
well restrain motion in the third
direction will use the cylindrical
coordinate system one from application
region we want to select stop nudes add
it and these bottom notes add it ok and
apply so now we have that now we can go
ahead and run our analysis move over to
this tab click entire model under
solution type that's so like
response using the direct formulation
click ok let's modify this default sub
case by going to sub cases selecting
this default sub case and select sub
case parameters here we'll define our
time steps we want 750 steps and their
Delta T's are 1 e to negative 6 so
that's a 1 microsecond
click OK here click OK here click apply
here cancel and click apply it to submit
this for analysis once this is done I'll
go ahead and hi my model tree I'll
import my results here the results tab
and I'll first make a graph using this
tool here here I'll click this icon here
to display all the results so select
this first result scroll all the way
down hold the shift key and select this
last result one thing I want to watch
are my translational displacements and I
want to view this for a few select notes
so pick any three nodes basically so
I'll select this one the one in the
middle here and this last one so once
that's good to go I'll hit apply
and I'm just select the X component
actually you'll notice that the results
are not the way they are supposed to be
so let me quickly review the model
around the model tree
I suspect it's pressure that is actually
correct let me inspect the load case
modify this
that is correct
maybe the field is not correct that is
correct now I'm wondering what may be
wrong with this
if I go back to the results that is
correct
scroll down this and I've got this a
little bit further under solution type I
have transient response that is correct
your sub cases this may not be cracked
it's when e to the negative six hit
enter click ok ok here click apply here
yes counsel and resubmit this
here it seems increments were too small
or too big let me import the results let
me look at the graph again and I view my
displacements my radio displacements and
that would be the X component for same
notes I should obtain the same or the
right plot and that is actually what I
do get and let me select our view ports
now it's disappeared
we have the model tree
I've actually occurred a error here let
me delete this plot it's actually not
there now let me save this actually and
close out of it let me go ahead and open
patch on again let me open my model
again this is problem 19 and it's
actually crashed now that's fine I'll
just have to recreate this so I'll start
a new patch run session or patch on file
over here I'll call this one problem 19
new you all right now I have an empty
session what I can do is somewhere we'll
cover the data so here under source go
to Nashville and put file and put your
die BDF file now that's in here under
analysis click X D be on your select
result file you'll find problem 19 X DB
is still there
click OK and apply so now when I go to
results my results are still here let me
do a graph now it can be the
translational displacements for radial
components and let me select those three
nodes again so it could be any one of
them this one the one in the middle bout
or one let me click apply and here's out
plot I'm gonna tell the viewports and
now you can see that and the problem
asks us to do one last thing
that is view the radio displacements for
notes one through seven so I'm assuming
that would be along the the edge there
but that would be for static
displacement so I'm wondering if that's
available to us and most likely not yeah
in the problem they would let me read
this real quick here for a single degree
of freedom system and instantaneously
apply a load will give a maximum
displacement that is twice the static
displacement at the same applied loading
so when I look at this
this is actually for the static
displacement and I won't take the time
to go ahead and do that one here make
sure to save your model and this
concludes this example