Hello!
I'm a bit puzzled about fatigue and crack propagation.
Given a SN curve, this one will predict for a specific level of stress what number of cycles are required to FAILURE, let's say 10e6 cycles.
Assuming an initial flaw of 1mm, and using Paris' law, a crack propagation analysis by...
Hello!
I try to understand why a shell is stiffer than a plate. I've read a note on the internet explaining that moving a point out of the surface of a thin shell like an egg takes more energy as the adjacent fibers have to be stretched, unlike a plate.
But it does not make much sense, and I...
Hello!
I'm currently working on a structure made of Titanium, Ti-6Al-4V, and it is heat treated to improve mechanical properties. So I''ve been through a lot of books, documents, internet to get a better understanding of the heat treatments, and now I'm a bit confused. So I need some help to...
Hello!
I would like to assess the stress level at the location of a weld. Basically this is a tube into a solid; so the interface will be the surface contact which is a cylinder in that case.
I'm aware that there is a connector menu in femap which has the option of weld, but i don't think I...
Hello!
I'm running a FE stress analysis, and checking the maximum Von Mises stresses, the values remain under the yield strength.
However, looking at the maximum principal stress, there are values above the Yield Strength.
So I'm a bit puzzled, according to VM there will be no yielding but...
Hello,
I've started a thread in another forum, but following advice of one of the member I post it here as my analysis is applicable to a pressure vessel.
So here is the summary of the problem, hope someone can give me guidances and good information to progress!!
Thanks!
I'm currently going...
Hi all,
I'm going through dynamic analysis, and I've got a simple question: why is it so important to have the structure outside the sine environment??
If the first natural frequency is outside this range, let's say above 100 Hz, it doesn't mean that it will not be met.
Hope someone can...
Hello!
I'm currently going through buckling analysis, for a hemispheric shell. So it a basically a portion of a sphere.
It is subjected to a pressure load on the external surface, therefore it can buckle.
From handbooks I could calculate the thickness, radius and angle using handcalcs.
But I...
Hello all!
I'm working on crack propagation, and I have a few question about propagation.
From my understanding, fatigue will iniate a crack along the shear plane (so 45 degrees for tensile loading).
Then a crack will propagate perpendicular to the loading.
Then stress intensity factor is...
Hello!
I have a question about post processing a model. It seems that regarding what option we chose, the results are very different, at least the contour looks different.
What I don't understand also is that there seems to be a sort of stress concentration at the location of the geometric...
It's quite convenient using the meshing toolbox to modify the mesh size on curves, in order to have a better mesh.
But that's a bit of the problem, the choice of the number of elements chosen is sometimes a bit random, until it becomes regular.
I'm working on a solid model with tet10, and I try...
Hello!
I'm running a linear buckling analysis of a curved shell submitted to pressure load.
I would like to check if there is snap through. It is pinned all around the edges.
Looking at the first mode shape, it looks like a snap through shape, so if the buckling factor is lower than 1 means...
Hi Everybody,
I've been working now for a few months on FEA, and what I found sometimes difficult on top of the analysis itself is the way I organise the files and the work.
It's usually required to modify the design, or the mesh, try different load cases, or analysis type etc etc. So from a...
Hi Everyone!
I'm facing a bit of a challenge that I would like to share with you.
I need to apply enforced displacements on many nodes (nearly 1000), I manage to isolate them in a group, and the value of the displacement to apply is a factor times the node coordinate.
So the issue is: how do...
Hi All!
I'm trying to get my head clear with the output I get, in particular the displacements.
Is there a way in Femap to visualize what the output coordinate looks like? I've got a model defined in Cylindrical CS, and output in Cylindrical. But is this output CS defined relative to the...
Hello everyone,
I try to model a cylinder of internal radius a and external one b. The structure is submitted to a radial pressure p. The cylinder is opened on both ends.
From books, there is a radial and hoop stresses, but the z-stress is equal to zero. I don't understand this point as I...
Hi everybody!
I've got a question about results I obtain from SOL101 and SOL106, which are massively different, so I wonder which one is the most accurate.
The analysis is a pressurized plate, pinned at both ends.
Linear Static analysis predicts a pretty large deflection, and a high max...
Hello!
I have a question regarding the unzip command on Femap. I have tried it on a simple example, shown attached which is a flat plate fixed on one end and pulled on the other one.
I have unzipped 2 nodes, with connection type set to None. This creates duplicate nodes, but the mesh remains...
Hello,
I have a solid geometry that I would need to include in an existing model mesh with solid elements. As it required to connect TET and HEX, it seems that the best option is to create a glue connexion between those solids.
I'm not familiar with this femap capability, so I'm trying on a...
Hello everybody,
I've have to deal with stability which requires a buckling analysis. Howevert, I don't really have a clear idea of the difference between linear and non linear buckling!
What's the difference, and/or how can we decide wether or not it's linear or non linear?
thanks a lot for...