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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...

Thanks FEA way, but does this also apply to shell forces? What is a Von Mises "Force" extracted from a shell element?

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...

So then would it be reasonable if I sized the tee section based on the resultant force R? Thanks

Thanks for the response! I should have stated that the drawing attached is not to scale, sorry. In reality, it is as you would expect, thinner. I see what you’re saying. I’d overlooked the moment M. But would that moment M exist somewhere at the center of the tee section (where the web and...

Thank you for the response r13! But for step 2, wouldn’t Fz be the force component that creates a torque at the center of the bolt group, not Fy?

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)...

Mustaine3, what are the benefits of using specialized codes to determine the fatigue life as opposed to determining it within FEM? Or in other words, why would one prefer having to extract FEM results for an external calculation over keeping all the work within one program (FEA)? Thanks

Are the results from a fully FEM analysis typically realistic enough to accept with confidence, as a static analysis would?

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...

Thanks dmapguru! That makes perfect sense. You seem to have a deep understanding of Nastran, so I was wondering- could you possibly help answer another question I have? Not sure if this violates posting by asking here, but do you understand what the use of a .pch file is? If it contains...

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...

Thanks for both of the responses. After looking through TR-12 I was able to find some figures that resemble my drawings (slight differences because of different assumptions, etc). WeezerMike, if it’s not too much to ask, I’d appreciate hearing your thoughts in more detail. I know that I did...

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...