This is the second clip in a two-clip series on thin-walled pressure vessels. In this one, I do some sample calculations on some representative shapes.
Great video! Thank you. Question though....how come you don't add up the Hoop and the Axial stresses using the principle os superposition to get the sum of the stresses. I mean think about it...if tube that has internal pressure and experiences hoop stress+ I add endcaps and now I have 1/2 hoop stress just 90 deg offset...that significant! Shouldn't there be a net stress in some 70deg or so!?
Sr. Great material I have follow you for a while and from time to time return to your videos. I'm wondering if you have one to explain pressure vessel head design consideration. Flat head type design vs. Hemispherical head and stress calculation comparison between both.
Hi there! You're videos are amazing but i'm having problems understanding the last one. Shouldn't you use Trescas formula for calculating the pressure? Sigma 1 - Sigma 3 = yield stress? Cheers
Hello sir , I learned a lot from your videos , Can u help me in two points regarding thin wall vessel , Do we use the Yield stress or ultimate stress to design the same , I think yield and you mentioned in the Video yield but please confirm , also for the "dish ends" do I consider stress =pr/4t or stress =pr/t?
Mr. French, if we have a hallow metal sphere, what forces act on the sphere if we sunken the sphere in the ocean, and at what depth we can sunk the sphere not to exceed yield stress. Thank you,
+Fatih Bilge Yılmaz Ok I did some research and it turns out. Longititional and hoop stresses are the principal stresses because there is no shear stress.
power of three came from 101.3kPa as that's the equivalent of 1 atm. Converting that into Pa only you should multiply by 1000 or 10^3. Also, 10^6 came from MPa. Mega is 10^6. Hope it helped
hoop stress is twice the longitudinal stress....so if you calculate hoop stress you are basically calculating the maximum stress on the vessel.....and we need the maximum stress!!!!
Nobody notices that he makes a mistake in the calculation of the hoop stress, the result is 937 Mpa, and not 93.7Mpa according with the properties of the material (300Mpa).. That vessel will explode
its way beyond any compliment ..the way u teach sir...my life will be meaningful if i get a chance to learn civil engg 4m u....thanks sir ..
Thank you for videos. They are really useful for engineering students
I'm a 4th year engineer graduating in december, I still find your videos extremely useful, I wish my professors were as organized as you.
All of your videos are infinitely awesome!
On a good-bad scale, that's bad. I love this guy! Great instructor and makes it easy to understand.
@philg24 Good luck with the exam. I'm glad the videos are helping. Thx much for spreading the word!
RMF
Thanks mate, it seems that you (if you're not already) would make for a wonderful teacher/professor.
Wonderful, you're most welcome - RMF
Why do you use the formula for hoop stress to layout a pressure vessel rather than the von Mises stress? Thank you.
@amrhass Very good. I'm glad the videos are useful to you - RMF
Great video, very easy to follow. I am currently using these to help prepare for final exams!! :D
Great video! Thank you. Question though....how come you don't add up the Hoop and the Axial stresses using the principle os superposition to get the sum of the stresses. I mean think about it...if tube that has internal pressure and experiences hoop stress+ I add endcaps and now I have 1/2 hoop stress just 90 deg offset...that significant! Shouldn't there be a net stress in some 70deg or so!?
Thank you for working in metric units!
These exercises always performed with positive gauge pressures, but can be applied to negative pressures (vacuum)?
Also is it possible to briefly cover thick cylinder pressure vessels? Thanks a lot!
Sr. Great material I have follow you for a while and from time to time return to your videos. I'm wondering if you have one to explain pressure vessel head design consideration. Flat head type design vs. Hemispherical head and stress calculation comparison between both.
Shouldn't you calculate the trescas or von mises reference stress? Is that only relevant for thick walled or is it never relevant?
Hi there! You're videos are amazing but i'm having problems understanding the last one. Shouldn't you use Trescas formula for calculating the pressure? Sigma 1 - Sigma 3 = yield stress? Cheers
Hello sir ,
I learned a lot from your videos ,
Can u help me in two points regarding thin wall vessel ,
Do we use the Yield stress or ultimate stress to design the same , I think yield and you mentioned in the Video yield but please confirm , also for the "dish ends" do I consider stress =pr/4t or stress =pr/t?
Mr. French,
if we have a hallow metal sphere, what forces act on the sphere if we sunken the sphere in the ocean, and at what depth we can sunk the sphere not to exceed yield stress. Thank you,
Great video! "Blowing up propane tanks..that's bad!" haha!
you sir are amazing! thank you for every single video :)
@n29bodyjump Thanks. I hope it helps with your classes.
What is the suitable safety factor for Pressure Air Vassel with working pressure at 10 bar at normal temp from -10 to 50 Celsius
this video helped me out so much, thanks!!!
what about making von misses to compare with sigma??
what safety factor would you use?
Why didn't you merge longititional and hoop stresses using Mohr's Circle rules to find principal stress?
+Fatih Bilge Yılmaz Ok I did some research and it turns out. Longititional and hoop stresses are the principal stresses because there is no shear stress.
is there any video for thin wall spherical pressure vessel?
Thank you prof. its value thing..
why didn't you calculate the pressure on the hemispherical caps
"Blowing up propane tanks that's BAD."
could you please put up videos for thick walled cylinders...thanks
what would you do to apply a safety factor, say if i had to work out max pressure with a safety of 4 would i just multiply my end result by 4. thanks
yes
Estoyz Aclan one more question what formula would you use to work out pressure from a given strain
I apologize I can't answer that question for now. Currently taking up Mechanics of Deformable Bodies and we're just on the Axial Strain lesson :)
im getting lost when your adding 10 to the power of 3 or 10 to the power of 6 into the equation, where do them numbers come into it ?
power of three came from 101.3kPa as that's the equivalent of 1 atm. Converting that into Pa only you should multiply by 1000 or 10^3. Also, 10^6 came from MPa. Mega is 10^6. Hope it helped
very good class!!!
thanks much you are helping me
thank you very much!
prof..
why you didn't calculate the longitudinal stress??
for what reason??
hoop stress is twice the longitudinal stress....so if you calculate hoop stress you are basically calculating the maximum stress on the vessel.....and we need the maximum stress!!!!
i don't understand prof. why you didn't use the mean diameter of d-t??
on the second problem... 200mm is already the mean diameter (denoted by Dm)
For your last example. The mean diameter is not 0.02. It is (0.02-0.006)
no it is 0.2. remember 1m is 1000mm, his D is 200mm so 200/1000=0.2
thanks man you help alot😎
thanks much
it's Stu from Hangover!
what is y refer to ?
+mido sad Yield stress, the maximum stress that the material can handle
Dm is given here so we can directly take that.....if in case outside dia will be given then it will be Do - t........
Nobody notices that he makes a mistake in the calculation of the hoop stress, the result is 937 Mpa, and not 93.7Mpa according with the properties of the material (300Mpa).. That vessel will explode
Umm no.
Luis Arrieche He is correct, it is almost 93.726 MPa