buckling on composite materials

[Dmaz]

Hello everyone!
Can you recommend a tutorial or guide to explain how to set a buckling analysis on an ansys laminate?
I also saw that there are two types of buckling analysis in ansys, nonlinear and eigenvalue. Is there one preferable to the other?

 

[_Max_]

Hi.

I link you with the guides I used to try to figure out how to set nonlinear buckling simulations (on the pet in my case)

1- https://confluence.cornell.edu/display/simulation/linear+column+buckling+-+problem+specification2-http://www.simutechgroup.com/images/newsletter/tips%20tricks/pre-buckled%20shape%20in%20nonlinear%20buckling.pdf

with regard to analysis preferences.. Well eigenvalue (linear buckling in wb) is the simplest and fastest, but obviously the least accurate.. typically use it before nonlinear analysis to get an idea of what awaits you

nonlinear analysis is longer and heavier mooolto.. But it's much more customizable.

I hope I've been a little help

in any way wait and you will see that someone more experienced than me will come to your rescue

Hi.

 

[turbin87]

Good morning to all
I would need a vital aid for my thesis politely
I have to make a chair made of composite material.I have created the outer surfaces of the chair(schienale and sedua) providing these surfaces the shell91 element. after that with the real costant I created three layers of different materials, on such surfaces. the volume between the external surfaces I modeled it and after that I assigned to this volume solid95 to which I assigned only one material. my question is how does ansys understand that it has to consider external surfaces and volume as a single piece? Moreover when I apply a distributed load on the line, since there are two matching lines (real to the shell surface and that of the solid volume) how do I understand which is the right line and how do I say I have to apply it in x direction for example?
I thank you in advance for your attention and kindness, I would be very grateful.

 

[stefano.garbin]

Dear Turbin87,

1-do not queue to another post with a new request.
2-study ansys tutorials well (we have put a lot of useful links for who, like you, is learning to use the program)
3-when you have made points 1 and 2 I recommend you to model all composite parts with surfaces, use the shell181 element (or shell281) and use the so-called sections, in which you can easily define the layup of the conposito, even with filling material such as foam or other, without using that slaughter called "real constants".

 

[turbin87]

I do not know how to create a new discussion
the professor necessarily wants me to use shell91 and solid95.
In any case I have read the tutorials that you have recommended me but I would like to help because of my thesis.
Suppose I have created a composite beam, with a 30 mm thick pvc in the middle, at the top I have made 5 layers of different materials, at the bottom I have made three layers.
so basically I used solid95 for the soul in pvc and shell91 for the various layers.the prof told me to see what is the value of cutting to the interface between the pvc and the layer of adjoining material. what I would like to understand is this: Since I have created two series of layers (superior and lower) with the same shell91 element, as for the element table I am given a table in which it tells me that the cut along xz I get it by inserting smisc(as item) and a number reported to the lower part of the laier iesimo(2*i)+7, then I would like to know how to plot to understand which serious yes of layers I am referring to and then what does
Thank you very much in advance and I still apologize if I don't create a new discussion but I don't know exactly how to do it.

 

[Onda]

to evaluate the cut to the interface just evaluate the cut inside the solid element. Having this a very lower stiffness of the skins, cutting in the core is practically constant, so cutting at the interface is equal to cutting throughout the soul. Moreover the suggested approximation is conservative because the cut has the maximum at the center of the neutral axis (for a symmetric laminate) for which to evaluate the bonding of the core with the cut found in the solid element is correct.

 

[turbin87]

thanks for the
reply you were very kind. I wanted to ask you another confirmation.
when plotted the tangential tensions of layer 1 in this way:
layer,1
♪
click on plot results
click on contour plot
click on nodal solution
Don't I also get interlaminary tensions?

 

[Onda]

non ho idea, nastran use.

 

[turbin87]

ok thanks the same for the answer