Recent content by inertia4u

I recommend you call the ACO or the engineer listed on the AD to get your answer. Everything posted here is speculation. PK ----- Nert

Hi FJCV - I spent last weekend looking for alternate references - namely because I know I've seen that "Figure 4" plot before from another reference. NO luck. That being said, my guess is that "St. Mech. Note 15" is may be an internal Grumman technical note. Out of curiosity, have you tried...

nolovenodie: Another option is for you to try finding an experience engineer and make him/her your mentor. Keep pestering your mentor until you get a grasp of it. If you still don't get it, ask around. One thing I've found over the years is that if the engineer knows "it" and "understands...

I'm sorry, but I disagree with rb1957. You can not cripple sections which are flat. You need corner in order to get a "crippling stress." Wingsmith, I recommend you take a look at the Handbook for Stability (do a search in the NACA Technical Report Server for that title). I've done some...

Hi tg, AC stress guys don't do any welding analysis, unless it is on secondary structure (like scuff plates near door openings), and then if necessary, the analysis is very simplistic. Good Luck, Nert ----- Nert

Oh, and don't feel like it is to late. A good buddy of mine 2 years ago did practically the same thing, and he is older. ----- Nert

Come on over, youngin' :) Brush up on your classical analysis techniques, and you'll be set. ----- Nert

I think mcclain hit the nail on the head. ----- Nert

Fatigue will be your main problem. My first stab at reinforcement would be as follows: I would up the gauge to 0.032". Install minimum of 3 1/2 rivet rows around the cutout. Allow for generous radius for the cutouts. ----- Nert

For those still wondering, "pocketing" is indeed the chem milled pocket of skin (reduced thickness). ----- Nert

mathlete7, Yes you can set the division between elastic to inelastic at the yield point - which is a slight over estimation. This is because what you are interested in the proportional limit of the material, which can range between 70-80% of Fy or aluminum materials (See MMPDS regarding how to...

Richard, Per your first paragraph, yes, the McComb chart essentially comes up with an effective length column based off of the rotational stiffness at the ends of the column. I am not aware of how ESDU actually does this, however. Regarding your second paragraph, yes, you are correct. The...

stresscalcs, A very hand reference I found for columns, beam columns etc is William McCombs Engineering Column Analysis The Analysis of Compression Members I ended up picking it up from thattechnicalbookstore for around $40US I double checked and he does have long column with elastic...

One more thing, It may be that you are assuming that J-E follows along the Euler curve (which is typically shown in structures manuals like Bruhn, etc). But this really isn't the case. The J-E equation and the Euler Eqn are 2 different equations which intersect at 1 point. The J-E curves...

mathlete7, No, you should not just do J-E as default. In fact, if you were to use J-E on a long column, it is possible to get a negative value (tension) as a result, which of course doesn't make sense. As an exercise, just plot the J-E equation as a function of L'/rho and then Euler as a...