Learning Forum

[Rameez_ul_Haq]

Could anyone tell me the difference that how does the value of layer and ply differ if I want to know the equivalent stress of a composite structure? For ply, it is evident that it shows the stress values for a specific ply only but I want to know how are the calculations made if I choose the layer option? What does layer option actually mean and how would using the stress values retrieved after selecting the layer option be helpful in any case?

And also, what does the position mean (default set as top/bottom, so what if I change it to top only or bottom only?)

[Rameez_ul_Haq]

Need help on this one please?

[Rameez_ul_Haq]

Can anyone guide me on this one?

[Rameez_ul_Haq]

,if you could help me with this one, I would be grateful. Thank you.

[1shan]

Please have a look at - https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v201/en/wb_sim/ds_shell_element_results.html. I am not entirely sure but it looks like the 'ply" terminology is applicable when you define composite using ACP(imported plies object), while "layer" is used when you define it using the "layered section" object. Someone with a better understanding of composites might confirm this.
Regards Ishan.

[Rameez_ul_Haq]

,actually even if I define composite using ACP, still both the options are available and I am confused which one should be used and when.
,maybe you could help us here, please?

[Rameez_ul_Haq]

,could please share your views on this please?

[peteroznewman]

I don't use Layers or ACP in ANSYS so I can't answer that question.
For shell elements, there is a thickness and a top side and bottom side. The default display is to plot the stress on the top fiber on the top side of the surface and plot the stress on the bottom fiber on the bottom side. If you turn on Thickness on the display, you can even see a contour connecting the stress value on the top side to the bottom side.
You can override this and plot the stress on the top fiber on both sides of the surface. Same with bottom fiber.

[Rameez_ul_Haq]

,if you don't use ACP then how do you model a composite? I mean when I insert Equivalent stress in the solution free, under the 'Sub Scope By' option, I can either select Layer or Ply. I actually wanted to know the difference between these two and what actually should be used when.
"The default display is to plot the stress on the top fiber on the top side of the surface and plot the stress on the bottom fiber on the bottom side.", so you mean to say that if I stay with the default position i.e. Top/Bottom, then the eqv. stresses at the top face and at the bottom face could be seen at the same time of that surface body?

[peteroznewman]

I model composites in Nastran.
Yes, the default position, Top/Bottom, is the most useful plot option because you can spin the model around and see the Top stress on the Top side of the surface and the Bottom stress on the Bottom side of the surface.