Hi DriveMeNuts,
Thanks for you reply.
I think I was confused by the concept of a stiffener and reinforcement: I call these extra bars "stiffener" but in fact I think I should not simply call them that. Like you said, they don't only stiffens the plate but also reinforces it. Yes if it's just...
Hi All,
Thanks a lot for the replies. I'm mainly working with vacuum chambers and in my case, the stresses are the highest at the adjacent walls. I did some quick FEA study and they seem to reflect what Compositepro says (Sorry I'm having troubling uploading images so I attached the file in the...
Thanks to everyone! Another question on this: Why does the stiffeners (like the ones on the chamber in the picture) stop about 1 or 2 inches away from the edges? Wouldn't it be stronger to make it all the way to the end?
Regards
Hi folks,
This might be an obvious question but it has been in my mind for a while. Why are some of the stiffeners on a flat face of a pressure chamber chamfered? See pictures attached. I couldn't justify why they are made that way...
Hi Prex,
Thanks for your reply. Do you have any suggestion on how to improve the model? It's a really simply model and I don't have much clue on how I should improve it...
regards,
XS
Thank you all for your replies.
So now I'm applying chambers to the chamber of 6mm (represents the weld fillet) to see what I can get from it..
r6155, Yes that is a very good point, but I just want to at lease make sure the design is not too off by simulation. I don't really have much...
Hi EngDesServices,
I did the calculation with ASME VIII DIV 1 appendix 13-7 (a),UNREINFORCED VESSELS OF RECTANGULAR CROSS SECTION.
Yes the biggest stress value appear at sharp corners, it's just I'm not sure in manufacturing how they would make the corners not sharp? To what degree should I...
Hi Michael,
Please find the plots attached. Also I attached another result plot with solid mesh (I know it's too many elements but I just wanted to make sure there are 3 elements along the thickness and this is a simple geometry so I just mapped the whole thing with super fine meshes). I also...
Hi TGS4,
Thank you for your reply. Yes you're right. I have updated the post.
I did figure out which stress to compared with in FEA but I'm not getting good results.
Regards
XS
Hi I’m trying to verify in FEA my hand calculation of a rectangular chamber subjected to external pressure.
It's a chamber with rectangular cross section (see attached picture) whose inner dim. are 22"*24"*57.25". It has equal wall thickness of 0.75". The material is Aluminum 6061 T6 with a...
Hi r6155,
This does help a lot, Table 11.4 is exactly what is needed. Except that, I think the case that applies is case 8, all edges fixed.
Regards,
XS
Yes I agree with your statement of how the direction of b is relative to the bending stress. However from where do we know the bending stress is in the direction of h not Lv?
Regards,
XS
Hi all,
I'm now at the stage of calculating ligament efficiencies in designing my chamber here thread794-463774.
I have three types of plates with holes to which CF nipple tubes will be welded on. Type one is a plate with one row of 4 uniformly distributed 6" holes on the centre line of the...
Hi SnTMan,
This seems to be a very interesting question - I myself have been wondering about the answer when designing my chamber these days. However, I might have a different opinion from you. It makes more sense to me if b is along the direction of h (for long plate) or H (for short plate)...
Hi SnTMan,
Thanks for your prompt reply. Actually it starts to make sense combining what you said and the Code:
1)Yes I couldn't find any statement of Pe being negative in the Code, but after a close look at the equations in 13-7(a), the pressure P is always a value you can extract from all...
Hi SnTMan,
Thanks for the reply. I have one noob question though, when applying external pressure, do I set the sign of Pe as negative(-)? I supposed so because I think in the case of an externally loaded vessel, the membrane stress should be compression and thus negative sign. Please let me...
Hi SnTMan,
Thank you for your time to run the calculations. Yes I agree this is a not difficult case at all - just my first chamber design thus all the beginner's questions..
Also I forgot to mention that the chamber is split into two equal sized halves by the plane along the 60" direction...
Hi SnTMan,
Thanks a lot for your comments.
Yes I guess another safety factor of 4 does sounds too unnecessary, I might start with what I get from the code plus an extra 1/3 onto the minimal thickness.
I apologize for not having put more design details. I have edited my post so people will...
I know no one has replied it yet but I just want to add that looks like I misunderstood the concept of reinforcement and stiffeners.. I will add also stiffeners around the chamber. Again, I think I won't be able to find any specific codes to my case but is there anything that I can at lease...
Hi all,
Edited: The chamber is roughly 24"X24"X60". It's for insulation of a cryostat but the temperature of the chamber itself is at room temperature. The potential material could be Aluminum 6061 T6 or SS ANSI 304. The reason why I consider Aluminum is that it might be cheaper than a...