Thanks for appreciation... We have covered more videos on Undamped free vibration including theory and Numericals...so check out that videos...and if you have doubt then comment us...✌👍 Here is the link for playlist DYNAMICS OF MACHINERY: ua-cam.com/play/PLwpA_XrwdvgZdUjaiINtHxzw_wIdfO52_.html
We know that for linear vibrations, spring force is F = k x. But for torsional vibrations, 1) Force F will become torque 2) stiffness k will become torsional stiffness Kt and 3) linear displacement x will become angular displacement 'thita' That's why we get external torque = Kt × thita This external torque is in the opposite direction of motion of disc.
Well, it's simple! You can take example of ceiling fan, or any other machine which has a bearing on the shaft for the rotation of rotor. Note: In this theory, the rotor is having bearing just like a ceiling fan, and the shaft is static (same as the case of shaft of fan), the shaft is having some stiffness and that is torsional stiffness.
@@EducationLessons Sir jii but when rotor has bearing and is rotating , so the shaft won't oppose the rotation na bcz of bearing?? They how does the torsional vibration come here.. sir ji in the video u explained the shaft was opposing the motion so there will be torsional vibration...that I can understand.. But when shaft itself is allowing the rotation of rotor bcz of bearing then why torsional vibration comes ... Plz explain sir ji....
Yes bearing reduces the frictional force, but there are other torque which acts on the rotor (like restoring or inertia torque due to motion of the rotor, WHICH ACTS OPPOSITE TO THE MOTION), also there are some frictional forces in bearings also, the shaft is having some stiffness and THIS TORSIONAL STIFFNESS ACTS OPPOSITE TO THE MOTION. So all these inertia torque and stiffness of shaft will try to oppose the motion of rotor. In this way, clockwise and anticlockwise torque acts on the rotor. This creates torsional vibrations...
Your welcome Check out more on our channel and comment us if you have any doubts. Here is the playlist: ua-cam.com/play/PLwpA_XrwdvgZdUjaiINtHxzw_wIdfO52_.html&disable_polymer=true
Your welcome Varun...don't forget to check the numericals on Undamped free vibrations. Watch it in our playlist and comments if you have any doubts. Here is the playlist: ua-cam.com/play/PLwpA_XrwdvgZdUjaiINtHxzw_wIdfO52_.html&disable_polymer=true
![Energy Method NUMERICAL-2 (Undamped free vibration) [Dynamics of machinery]](http://i.ytimg.com/vi/Bmn6TVah5fw/mqdefault.jpg)
sir agar disc ko anticlockwise rotate kare toh kuch alag ho sakta hai kya
incredible lacture 💯👍
thanku it helped ☘
Please cover full vibration .....
thank you ..
And keep your work up ....
Thanks for appreciation...
We have covered more videos on Undamped free vibration including theory and Numericals...so check out that videos...and if you have doubt then comment us...✌👍
Here is the link for playlist
DYNAMICS OF MACHINERY:
ua-cam.com/play/PLwpA_XrwdvgZdUjaiINtHxzw_wIdfO52_.html
which books we have to prefer for numericals??? does any one have idea??
RAC-IMPORTANT QUESTIONS_QUICK REVISION (pdf):
drive.google.com/file/d/13NEp_yotA7N1NY0vfnE_RVH0rBqbjrun/view?usp=drivesdk
DOM IMPORTANT QUESTIONS-QUICK REVISION (pdf)
drive.google.com/file/d/1Tb82RKOnA1mlfaU8mxQBdAC6si2ytVem/view?usp=drivesdk
why the external torque is Kt.theta?
wouldn't the external torque be the torque in clockwise direction?
We know that for linear vibrations, spring force is F = k x.
But for torsional vibrations,
1) Force F will become torque
2) stiffness k will become torsional stiffness Kt and
3) linear displacement x will become angular displacement 'thita'
That's why we get external torque = Kt × thita
This external torque is in the opposite direction of motion of disc.
Hello sir jiii plz tell me any real life application of a rotor and one end of shaft and the other end of shaft is fixed
Well, it's simple! You can take example of ceiling fan, or any other machine which has a bearing on the shaft for the rotation of rotor.
Note: In this theory, the rotor is having bearing just like a ceiling fan, and the shaft is static (same as the case of shaft of fan), the shaft is having some stiffness and that is torsional stiffness.
@@EducationLessons
Sir jii but when rotor has bearing and is rotating , so the shaft won't oppose the rotation na bcz of bearing??
They how does the torsional vibration come here..
sir ji in the video u explained the shaft was opposing the motion so there will be torsional vibration...that I can understand..
But when shaft itself is allowing the rotation of rotor bcz of bearing then why torsional vibration comes ...
Plz explain sir ji....
Yes bearing reduces the frictional force, but there are other torque which acts on the rotor (like restoring or inertia torque due to motion of the rotor, WHICH ACTS OPPOSITE TO THE MOTION), also there are some frictional forces in bearings also, the shaft is having some stiffness and THIS TORSIONAL STIFFNESS ACTS OPPOSITE TO THE MOTION. So all these inertia torque and stiffness of shaft will try to oppose the motion of rotor. In this way, clockwise and anticlockwise torque acts on the rotor. This creates torsional vibrations...
Torque acting on the rotor is already mentioned in this theory, with their magnitude and direction. Hope your doubt is cleared now...
Thank u very much dear Sir.....for giving me ur valuable time and replying......May god bless u
thnkss soo mch...
Your welcome
Check out more on our channel and comment us if you have any doubts.
Here is the playlist: ua-cam.com/play/PLwpA_XrwdvgZdUjaiINtHxzw_wIdfO52_.html&disable_polymer=true
Thanks bro❤❤❤❤❤
Your welcome Varun...don't forget to check the numericals on Undamped free vibrations.
Watch it in our playlist and comments if you have any doubts.
Here is the playlist:
ua-cam.com/play/PLwpA_XrwdvgZdUjaiINtHxzw_wIdfO52_.html&disable_polymer=true
Sir please upload forced vibration lectures of vibration
Yes, it will be uploaded soon👍
Please upgrade video quality