All,
I am a structural engineer primarily working on stress-skin structures - railcars, etc with a good knowledge of effective widths, stability etc.
Is a floor pan in an automobile considered structural? I have corrosion on a drivers side pan adjacent to what looks like a 4 x 4 cross-section...
All,
2 questions:
1) Is it possible to get chromium carbide precipitation in a low-carbon stainless steel grade, such as AISI 301LN?
2) Will passivation of 301LN stainless prevent carbide precipitation?
Thanks!
tg
Hello welding experts,
Does anyone know why modern North American structural welding standards do not cover Plasma Arc Welding since the mid-70's? Have we decided it is no good? Has it gone out of favour?
tg
Hi all,
Rail question on Forum with lots of stressed skin experts:
Any examples of semi-monocoque designs with really large openings? Imagine a stressed skin rail car with a 10ft wide x 15 ft high basic rectangular cross-section, 80 feet long, and openings are desired in roof measuring about...
Hi all,
We have always protected broken ends of Huck bolts with zinc-rich paint, when using C120 Grade 5 steel pins. It it a good idea to to the same with stainless steel C6? Or will the zinc-rich paint make it worse?
tg
Hi all.
If a high strength steel casting (ASTM A415) has inadvertently been welded to, I understand that low temperature notch toughness may be effected. Any guidance on how to evaluate how much it has, how to assess it, and potential methods of restoring the lost toughness?
Casting is part...
Hi all.
We are trying to size a steel member that will receive impacts from a Caterpillar excavator bucket's bottom edge (with teeth!). Think of this as a steel pad welded to a flat steel floor. Can anyone suggest a design load for the pad to floor connection if the bucket is expected to...
Does anyone have any guidance on evaluating block shear (tear-out) for a tension-loaded deep channel (C-section) only connected at its web, with a series of elongated ring welds? Can I assume the same fracture paths as with a bolted joint or is that too conservative?
tg
All,
Does anyone have a reference for the fatigue behaviour of bearing-type bolted joints in a counterbored hole? Main loading is shear alternating between zero and a design value. I imagine there is quite the stress raiser at the edge of the bore. This is for a steel freight car.
Thanks!
tg
Hi all.
There is a multitude of fatigue information out there. However, can you guys suggest references (articles, texts, standards) that are clearly explained and user friendly? We are looking at stress-life methods, using AWS D1.1 or Eurocode 9. EC9, by the way, is not user friendly.
What...
Hi all.
We are looking to reinforce a stainless steel stressed skin structure. The stainless steel used is 301LN 1/2 Hd. Someone suggested exploring the addition of a brazed stainless steel flat bar, because it may be easier than welding. Existing skin is spot-welded to stiffeners, but seems...
All,
Can anyone confirm the various designations for type 301LN stainless steel in 1/2 Hard condition:
I've seen
S30153
AMS5518
SUS301LN
ASTM A666
Are these all referring to the same thing?
Does anyone have a cross-reference website that could help demystify this?
tg
All,
Is there an accepted practice for modeling spot-welded stainless steel stressed skin structures? We are looking at using short beam elements to enable force extraction, but this is giving a very flexible model, and not correlating well with physical tests. In addition, the thought of...
All,
Regarding a stressed skin rail vehicle application, what do you use as maximum spacing equations to avoid inter-rivet buckling and how are they affected by in-service stresses?
I have used for years 1.8 t sqrt(E/Fcy), based on AAR (association of American railroads), where Fcy is...
All,
We are designing a tee joint between 2 steel plates 0.25 thick. There is no clearance for usual double sided fillet welds. We are looking at making a slot in the top part, extending the stem slightly upwards into the slot and filling up the slot with weld metal.
Is this done? How to...
Hi all.
Can you aerospace types (or others) remind me how you typically extract shear flows for sizing skin to frame member connections? I have not modeled discrete fasteners, but just used glued contact in my FEA. What is the usual method with "older" FE approaches, i.e. merged shell...
Hi all.
Do any of you use Alcoa-Huck Magna-Lok rivets in aluminum plate? Do you have any issues with blind side loosening because of the bulb shape providing virtually no blind side footprint? Is there a recommended blind side chamfer that could help this?
Plate thickness: 3/16
5083...
Guys,
Imagine a riveted connection without much clamp (such as when using Huck BOM fasteners)in an application where one of the members (7004 aluminum, thickness 5/8) is connected to another member (6061-T6 thickness 3/16). The governing load case is a proof load case resulting from a train-to...
Hi all.
Looking for guidance in appropriately sizing rivets (both well-clamped and not so well clamped) in bearing-type connections.
In lining up members in an axial splice, I am expecting some misalignment. Spacers will therefore be needed. The splice can be thought of as a long bolted...
All,
I'm still having trouble exporting, from FEMAP v11.1 files which have CWELD element types, as mentioned in thread825-354666. Our solver is NEiNastran v10.1.
I now believe this is an issue with FEMAP.
Any ideas on how to make this work?
tg
