No there is no forced vibration. The rod is flexible, and it is rotated by a motor. the motor position is the clamped support shown. So when the rotation stops there will vibration at the tip. to modal this, I need to find the beam boundary conditions.
Kk.. Please have a look ath the link below
http://ijiet.com/wp-content/uploads/2013/02/53.pdf
You can see, that the initial conditions here are easy enough to get and also proceed forward. In my case its not, due to the overhanging section
I am trying to make an equation like equation 10 in...
Hello,
Can anyone help me find the boundary conditions of the below given beam please. Its a clamped-free beam but the overhanging sectiona and the mass makes it confusing. Actually I am puzzled about finding the initial conditions.
I have figured out the problem. In order to understand the tip movement the peaks of the sensor readings should be used. This is direct indication of the tip deflection or oscillations to be precise.
This peaks cannot be compared directly with the encoder value. Why? Because, at the encoder...
Yes, that is true, but note that the current is in saturation here... which obviously means that is the max. acceleration possible.
This topic is exactly what I want to be answered. This was a good suggestion to explain the difference in values, thank you. If I can make sure that there is a...
For a position curve which is plotted for constant acc. equation is s=s0+v0t+0,5at^2. Please see the attched screenshot.I find a regression equation of the same form.
Yes, I have done the measurements in horizontal plane as well. The values are the same. And the movement is just one direction. 90 degrees, stop.
The thing is I am not looking for the acceleration at a time t. I am looking for the maximum value of acceleration. It can be that the 2 methods...
The ''figure'' shows the setup. While testing the beam showed vibration charachteristics of free-free beam and not of cantilever beam, that is, at 35 Hz which is the first mode, the beam vibrated with 2 nodes.
My end objective is to develop a Mathematical model to describe the beam rotation...
You can see the pictures in #7. The time between 2 consecutive peaks is the natural frequency. It was found as 35 Hz which is 28,6 ms. Also an FFT analysis would give the same.
Another method was also used. A function generator was connected to the motor. And the frequency was increased by...
This is a point I have been working for some days now. I have made some observations and one among that is:
The time to achieve maximum acceleration is a multiple of the resonant frequency. Please see picture attached in #10. Such a situation is ideal. In reality acceleration curve will have a...
Suppose the rod is standing parallel to the Earth's surface. Now the sensor reads 1,73 Volts from ground. For the accelartion I take this value as the base. Suppose the acceleration value read is 450 mV from ground, then the value is 1730-450 = 1280 mV. 1280/200 = 64 m/s^2. where 200 is the...
The time is controlled by the epos algoritham. I have nothing to do with that.
Yes, obviously decceleration would not end abruptly. Its a flexible rod, so due to sudden halt, there is free vibrations at the tip. Also the regulator plays a part in making the stopping a bit smoother. both...
Yes 3 oscillations per division. Each divison is 100 ms. So 33.33 ms is one oscillation. Inverse is 30 Hz...Rough calculation. Correct time stamps give 35 Hz exactly. Thanks for the help anyway. Will try out something.