MSC Nastran; Patran Tutorial - Direct Nonlinear Transient; Stress Wave Propagation with 1D Elements Video Lecture | Nastran: Basic Tutorial for Students - Design Softwares

in this video I'll be performing
indirect nonlinear transient analysis
we'll be looking at the stress wave
propagation along 1d elements I'll first
start by creating a new Patran session
my new file will be called problem 21
and the units for this example are
meters new and sand kilograms I'll click
OK here first to find my curve use an
XYZ method my curve is 100 meters long
in the x-direction I'll then go ahead
and define my materials here by clicking
isotropic calling material matte under
input properties I'll give it an Gunz
modulus of 1000 of Busan reach 0.3 a
density of 0.1 and the structural
damping coefficient of point zero zero
five
click OK and apply ours our linear
constitutive model I need to define an
elasto-plastic one
here I select turning slow for a
nonlinear data input my slope here is
100 my yield point is 10,000 click OK
hit apply and now you'll see I have two
constitutive models I'll go ahead and
apply the material to this curve and I
do this by going to 1d properties and
clicking abroad I'll call this property
prop on your input properties I'll
select my material I just created my
area is 1 meter squared from an
application region I'll select this
curve notice it's here and I'll hit
apply now I can move on to define my
boundary conditions the first thing I
need to do is create a time dependent
load case so here click load cases come
on you one time dependent or time load
case I'll make it current
so then anything after this will be
added to this load case or any boundary
condition will be added to this load
case I type is time dependent and hit up
hi
next I want to define a field a non
spatial one here I'll call the load
history my points will be time dependent
so I'll leave this checked under your
input data if you look at the example
here our load history is basically 1 or
1000 throughout the whole thing
I just need one value for this cell type
in zero type in 6 here type in 1 or
actually hit this one cell type in 1
type on 1 again
hit okay click apply at the bottom if
it's not there put your cursor in here
and hit apply now I can go ahead and
define my boundary conditions first I'll
go ahead and define my instantaneous
load here so here under nodal force your
new surname force or F will use the load
history we just created we'll apply a
1000 going in the leftward direction so
that's why the negative is there click
OK on your application region pick this
point add it ok and apply so now here's
your instantaneous force now we have to
apply our displacement constraints so
let's first define one for the route so
here type of route grampa data we'll
type in 1 for now for 0 sorry so this
will prevent translation in the
x-direction just at this point so from
application region we'll select this
point add it ok and apply for my next
constraint I'll call it all other
constraint from my input data this curve
will be restrained and to the 3 the 4
the 5 and the 6 directions click OK
select this application region so curve
1 ok and apply now I can go ahead and
move on to the meshing tab here I wish
to mesh the curve my curve list will be
this curve uncheck automatic calculation
my global edge length will be 5 meters
so in every element will be 5 and at the
end when I match this I'll have 20
elements on the length here
to view the numbers of the elements you
can go to the Home tab click table
control and turn on the numbers so one
through twenty that's done I can go to
the analysis tab analyze the entire
model I have to change the solution type
to non-linear transient under solution
parameters I'll turn off large
displacements and for my W for damping
factor
I'll give it a value of one point five
seven hit enter click OK at the bottom
click OK here for my sub cases we have
to modify the time-dependent sub case
you notice that this sub case makes use
of this load case alternatively what I
could do is use the empty load case here
in this scenario we have to load case
usually each sub case corresponds says
native load case but you can mix and
match the two but here I just want to
use the time load case as the
constraints and the force under sub case
parameters my ending time is 2.5 seconds
here I'll click automatic I'll click OK
click apply I'll click cancel and your
sub case select by default it will run
the default sub case with the default
load case but there's nothing in there
so we don't want to run this sub case we
want to select the time load case that
includes solo case with all the boundary
conditions so let me select ok and apply
it will analyze that low case once
that's done I'll click X DB to import my
results and hit apply now when I go to
results the first thing I'll check is
I'll create a graph make sure this is
selected
hit this icon highlight all of these
values I want to view my displacements
and the extra action and I only want to
view that for this node no 21 when I hit
apply here's my load or my response I
compare this this is actually what we do
get some time you zoom in actually now
to make the numbers a little bit easier
to read I'll go to display attributes in
here I'll make the values fixed and hit
apply now it's easier to read the values
so here the highest response is about
halfway between 1.8 2.3 seconds the next
thing they want us to view are the
non-linear stresses at the fixed end for
the element 1 so here what I would do is
go back to target entities select this s
elements select this element here
element 1 make sure you have all these
values highlighted and one thing I just
realized I forgot to do is add element
stresses to my output results so I have
to do this again under analysis click
entire model under subcases will modify
the time load case so make sure you have
it highlighted here and make sure you
have the same load case highlighted here
on your output requests select element
stresses simply click OK down here or
hit apply here
you should have displacement SVC forces
and stress here click yes to overwrite
the old one click cancel and click apply
to reanalyze this
once that's done let's import the
results and now when I click this icon
select every result here and I scroll to
the bottom here and why result I have my
stress tensor non linear stress is
available now I want to view my stresses
in the extraction which is long the
elements and again I want this just for
element 1 let's click apply let's shrink
this because it's always behind it here
you can see the response and it matches
this response here even the value is the
same let's do this for element 20 which
is at the free end so silicon than 20 if
you want you could type in elements when
you here click apply you'll notice that
is exactly the same response we have
here now sometimes a it's sort of
difficult to sort of hide or delete this
window so I'll tell you how to do that
under action click delete and select
object plots and select this one plot or
if you go to own in the model tree and
believe there's a check mark here that
lets you turn it off and on
alternatively you can just delete the
entire plot it's up to you save and that
concludes this example