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...
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...
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!
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...
Hello all!
I want to select the most critical RF for a composite panel submitted to axial, transversal and shear flow. It is modeled by several CQUADs.
I've run the FEM in Nastran and I have the flows in each CQUAD. But the question is: How to guess the most critical load case of buckling? To...
Hi all!
I am looking for some advice about compliances in stiffness and strength of an aerodynamic surface. In particular, wing leading edge.
I have to prove that panel's deflection is below 1 mm. To ensure this, is it necessary that loads of the panel and pressures be taken into account at the...
Is there any relation for buckling reserve factors between a flat panel and an analogous curved one?
The aim is to obtain results for a curved panel from results obtained in a flat panel.
Thanks all in advance.
I have a model in PATRAN which is loaded using SPCD in border nodes.
The forced displacement method (as far as I know) move these nodes according to inputs and then, clamp the node. So, I have a feeling that stress in the elements are not true (maybe clamped nodes take load), and only strains...
Hello all!
Well, my question is very easy for people who visit this forum (I am new in FEA).
Which is the difference between the types of MPC's (RBE2, RBE3, Explicit...) that I can model in PATRAN? I've been searching information and I've found the next:
"RBE2 is a rigid element that...
Hi collegues!
Here goes my question:
Is there any criterion (in order to prove a structure) about using limit or ultimate loads when the load case is a "fail safe case", it means, when a structural element is broken?
Thanks in advance.
Hello all.
Well, I am looking for some advice about how can I obtain the loss of rigidity in a curved panel when there is a hole in the middle of it (from buckling point of view). I've made two run in PATRAN/NASTRAN considering an intact panel model and another one with one hole. Is it the...
