So maybe the question is where does the 3 times its own weight requirement come from? I also see quite much to add 1.5 on top of that, despite whatever incident could have occurred in the past.
thanks SparWeb,interesting post for the limit load understanding...
I guess that, for some failure scenarios, limit load capability is enough for certificate the structure because load level is known (or accepted) not to overcome the associated to the failure case. So, isn´t this rational valid...
Hi guys,
just a confirmation... for large aeroplanes (CS25), when the plane is in Jack position; does it need to withstand just limit loads, isn´t it? So, once I have put the adequate reaction factors stated in CS25.519 in my analysis, no need for applying the typical UF=1.5 on top of them...
Hi mdhayes
Yes, that´s what I want to do! Simmulate a laminate with only a MAT2/PSHELL. Is this possible? My idea is to calculate the laminate properties and create a MAT2 (with the E1, E2 and G12 obtained for the laminate, but how?). Then, create a PSHELL calling that MAT2 where only I define...
Thanks SW for your post.
Well, what I want to do is to consider only membrane properties.
The reason why I want to use PSHELL/MAT2 is to have the flexibility of entering the properties I want, not the NASTRAN ones (internal calculations).
My model is a general FEM, not a detailed one...
Hi Steve
Let´s suppose next material with next stacking sequence:
Material properties:
E11=50000 N/mm2
E22=10000 N/mm2
G12=2500 N/mm2
u=0.3
Stacking sequence (6 plies)
(+,-,0)S
I´d create the corresponding mat8 for the material and laminate properties with a pcomp card.
The thing is: Could...
I have the same question Vorwald requested a couple of years before and didn´t receive any answer. I quote it:
I have a mat 8 card derived from a composite laminate properties (inverse of the A matrix of the ABD), and I have PSHELL/MAT2 generated from the PCOMP card. The answers are quite a...
Hi all:
I haven´t clear how I must to interpret the moments flow sign of QUADs in PATRAN when I plot internal loads (Create+Tensor+Moment).
For example, I have a QUAD and the corresponding axis system, where XY is the plane of the QUAD. In that axis system, the Mxx read in the QUAD means that...
Hi people:
Could somebody explain me the difference between simple and double shear in order to calculate riveted joints?
As far as I know, three pieces riveted together are a double shear example. Only two pieces riveted are simple shear. Am I right?
And if I´m right, in double shear all...
Well, I'm trying to do a hand analysis, but I don't know how to manage geometry and properties of the cores. Core of 25 means a core which height is 25mm (7--> 7mm). The panel is simply supported.
Actually, it is one sandwich panel where some areas have a core of 25mm and others 7mm.
Thank you...
Hello colleagues:
I have a sandwich panel with different core heights because of several actuators that are located in its inner area (it is necessary a height change).
In a transverse cut you can see (from left to right): monolitic area, core of 25,monolitic area, core of 10, monolitic area...
Hello again:
The panel is made up of carbon fiber (fabric). It is one of the panels that are between the leading edge and the wing torsion box. For the moment, I'm only considering in-plane loads.
What I was thinking to do is to take loads from the big FEM (it includes the entire wing) and...
Greg, I'm not referring to buckling modes.
I'd like to know which is the proper criterion to read flows when a panel is modeled by several QUADs in order to select buckling critical loads.
I mean, which load case has the most desfavourable components (Nx, Ny, Nxy) that give me the lowest...
12 plies' panel has two additional plies on each side. The laminate is symmetrical and the manufacturing process is identical.
Both panels only have in-plane loads.
To sum up, the only difference between the panels is the number of plies. Does the thickest take more load than the thinnest?
Hello!
I have a composite panel of 12 plies. I'm studying its buckling and stiffness resistance.
The problem is that the FEM which I am using to read flows (to enter in my calculations) has 8 plies.
It is supposed that a panel with 12 plies takes more load that the 8 plies' one. So...Am I...
