I'm fairly inexperienced with Nastran INCLUDE files, but I'm hoping I can use them for an analysis I'm running.
Basically I have an assembly with various panels, brackets, fasteners, etc and I'm trying to set up my model so that it contains two configurations. Both configs will be set up in...
Hello,
I have a question I was hoping you all could answer. A coworker sent me an FE model that he created, where he modeled a bolted joint using just an RBE2 element (with DOFs in 123) to connect the matching holes in 2 plates. I would never do this; my preferred modeling method would be to...
Hello,
If the title is confusing, let me explain. I'm trying to extract loads from a Patran shell model in the x and y directions. I could just separately extract the x and y components of the shell forces, but I noticed there is a quantity called "von Mises". I know that von Mises stress is a...
Hello,
Apologies for the crude drawing attached, but here goes. Given Fx, Fy, and Fz loads applied at the lug hole, I've distributed the loading into each of the 6 fasteners to size them. I've also sized the lug itself using the airforce lug sizing method.
But now I'm trying to size the...
Hello,
I’m trying to learn creep analysis in Ansys, and am currently working on deriving creep constants, specifically C1, C2, and C3 for the Norton Power Law.
I understand that the equation is usually shown in 2 ways:
epsdot = A * (sigma^n) * (t^m)
or
epsdot = A * (sigma^n) * exp(-Q/RT)...
I’m trying to wrap my head around different ways of analyzing a components high cycle fatigue life, since I’m now just learning that FEM software is (supposedly) able to perform fatigue analyses, given I set up the model correctly.
At my company, the method I was taught was to run two static...
Hello all,
I'm creating a 3D bolt load distribution spreadsheet that accepts loads in 3 directions and distributes them into a 3 dimensional pattern of bolts (so the pattern does not have to be on a single plane). I'm honestly lost as to why the spreadsheet isn't working.
I found this windows...
Hello,
Is there a difference in the stress concentration of a hole in an infinite thin plate loaded in biaxial tension vs biaxial compression?
I ask because in numerous books (one of them in the screenshot below), there is a calculation that determines the Kt in biaxial tension. I've also...
First of all, I’d like to apologize for any misleading information or confusion I may cause, as this is a topic I’m very unfamiliar with.
Basically, a customer provided me with a set of files with which to create and run a model using Patran with Nastran.
All of the files except one make...
The title seems pretty self explanatory, but the automatic constraints check box is located in “solution type” —> “solution parameters”.
And if I wanted to enable AUTOSPC through the .bdf, would that just be going to the PARAM section and adding a line for “PARAM AUTOSPC YES”?
I can’t seem to...
Hello,
I'm checking the bending of a bushing flange, where a high axial force (along axis of bushing) is essentially pulling the bushing through a hole and causing the flange to "kick up". How would I determine the moment and stress caused by the load?
I'm thinking, what if I convert the...
Hello, I’m trying to determine what the shear and moment diagrams of a bolt in single shear look like. Before anyone says it, I know that it’s rare that a bolt will ever fail first in bending, and this is something that typically isn’t even checked for.
Anyway, I’ve assumed that the bolt is...
I’m a (mostly junior) stress engineer and have been tasked with sizing a lug. Various loadcases have been run through FEM and loads have been distributed into the lug bolt for each. In other words, each loadcase has its own set of x, y, and z loads at the bolt.
An initial analysis...
Hello,
Is it possible to determine the compressive modulus of a polyethylene foam using the following spec sheet?
https://www.sekisuivoltek.com/wp-content/uploads/2016/03/Minicel_ProductSheet_Type_M_Data.pdf
It doesn’t contain any information regarding the compressive modulus, but does have...
Hello, I want to drop a heavy mass onto a "pad", or thick plate (potentially even a block if the thickness is great enough). I am trying to determine an effective axial stiffness with which to apply to the pad. I know that for a rod for example, the stiffness could be worked out to be k = EA/L...
Hello,
I have an interesting spring energy problem that I’m trying to solve. I have a spring (known k) attached to a releasable hook at the top and a mass (known m) attaches to the bottom. This is a drop test, so when the releasable hook detaches, the spring and mass fall together a set...
Hello,
Any help is appreciated with this analysis of mine. I’m trying to model a lap shear joint test, where two plates are bonded together with an adhesive and sheared apart with an in plane load.
I’ve modeled the plates as solid elements (Hex8). The bond has been modeled following the...
