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Try going to the bottom of the page and clicking on "style chooser". Then switch to "default style" and see if you prefer that.

I see in the forums that each post now keeps track of a "reaction score" (the thumbs up). Based on how this is accumulated (the up/down arrows on the right of each post), it seems like this is intended to be a direct replacement to the "little purple star" system. However, on the members...

Well, it really depends on what you are doing. As others have mentioned, it's a sensitive material to work with and I imagine most of the time critical loads are going to be dictated by boundary conditions and contact mechanics. But in general, like all materials, pure tension or pure...

The most common way, in association with instrumentation, would be dimensional tolerance checks. You know what the design parts are supposed to measure / look like. If you have permanent deformation, things would have shrunk or stretched in a way that is measurable. Preload/alignment at joints...

Possibly because these forums are used primarily by seasoned engineers who tend to be.. how should I say... more dour/cynical/"realistic" about these types of challenges than the average "techie" or cult-of-personality type follower of SpaceX that you might see on social media or tech news...

It's definitely a welding related symbol. It looks to me like it would indicate a 1-sided V-groove weld. The double line indicates the other side is the EOP and the curve on top indicates the weld material is to be concave. See...

I should note that superimposed on all of the charts in Section E is the following statement: "NOTE: CURVE DETERMINED BY A SEMI-EMPIRICAL METHOD WHICH ASSUMES THAT THE BUCKLING STRENGTH OF THE VARIOUS PLATE ELEMENTS CAN BE ADDED TOGETHER TO OBTAIN THE ULTIMATE STRENGTH OF THE ENTIRE SECTION...

Hi, I have the manual Volume II you are looking for, it is the same number DAC 25-2066 (3-71). There are curves for formed sections if you are searching for "compression panel allowables" which I assume you are based on your reference to Volume I B6.5.2.1. Unfortunately I have no idea what the...

Failure of joints is general in what we call "transitional" regime... neither pure bearing or pure shear failure. As mentioned it is commonplace to check bearing yield MoS. If your joints are shear critical and you are worried about yielding of the shank in shear, you have bigger problems...

Circling back to the thrust links (an no, I'm not trying to kick Boeing when they are down): The 777X thrust links are made from Titanium, although I'm not sure which alloy. Most thrust links I have knowledge of, including those of the 777-200 and 777-300 are made from 15-5PH, so they...

For strain-life analysis you need to index the SWT (or some other method) correct e-N curve with the cyclically stable local notch strain range. As you mention the material may have hardening/softening or relaxation properties which you can account for with a local notch strain analysis using a...

If I'm understanding what you're concerns are, you are saying the manufacturing process leaves the parts with a residual stress at certain details which will affect the mean stress during the duty cycle. If that is true, the "proper" way to approach F&DT with the spectrum factor approach is to...

If this is an OEM hole on every production A/C, then why did whoever got hold of the OEM FEM has to make the hole in the model? Likely the OEM doesn't put that level of fidelity in their model. They are probably using it as a loads model, and using some other analysis technique to substantiate...

Not as much, but it does create some. There is some guidance in the FAA course on repairs and modifications. We would generally use our own FEM studies to generate similar data. The way this would typically work is to boil it down into tabulated bending/tension (B/T) ratios for different...

Hey, at the end of the day there's always different ways to solve the same problem, sounds like you have a plan and guidance... but as a follow-up, my "two cents": I'm not really a fan of the modification intercostal design idea. I have seen this done before when I was working on major STCs but...

Maybe I'm missing something, but... why do the fasteners need to be countersunk? Are there specific aero requirements at play? Any reason you couldn't just use a protruding head rivets? Seems like the main concern at the top of the thread was avoiding knife-edging. Can't you just install an...

I worked for a 3rd party engineering company with two staff DERs doing post-production support for commercial aircraft (Part 25) for quite a long time and I have worked in a similar capacity for Part 23 aircraft. We were kind of the engineering support for several small airlines who didn't want...

By the way, I don't know what your situation was with this approver, but I completely disagree with whoever that was. Generally, it is not a good idea to simply compare net area to apply a factor to an existing margin. So many reasons why this could be completely inaccurate. I guess I'd need...

It is true that von Mises effective stress is a Hookean model (https://www.continuummechanics.org/vonmisesstress.html) It cannot account for level of ductility, Ramberg-Osgood shape factors, or hardening parameters. Analysis generally works by defining a limit load and then checking stresses...

This question has been discussed ad nauseam on these forums. I would start by searching "von Mises". Here are a few threads that I have personally participated in: thread16-512694 thread507-480814 thread2-413046 Here's a handy picture: There is an element of this where it can depend on if...