# vibration

1. ### Mass and vibration frequency

My query here is, Suppose there is a 2 kg mass To oscillate it/vibrate it, it will take some force and it will have some natural frequency Now I increase the mass to 5 kg so to vibrate it, won't it take more force and so at the end, won't the natural frequency of the object increase? as its more...
2. ### I Resonance gets sharper just by increasing the resonance freq, why?

The $Q$ factor of an oscillating system is defined as $\omega_{r}/\Delta \omega$, where $\omega_{r}$ is the resonant frequency, and $\Delta \omega$ the resonance width. As I understand, $Q$ measures how sharp the resonance curve is. Why is it that the resonance curve gets...
3. ### Transient vibration of an engine

How is the transient vibration of a piston engine usually simulated? I know that in order to define the vibration loading you need the mass properties and dimensions of the moving components plus the cylinder pressure curve. And of course you need to know the firing order, V-angle (if...
4. ### A noisy chiller

Dear forum members, We have a water cooled chiller device (see its model in attached link) and we use it to cool a hot mirror element. Unfortunately the chiller is vibrating and the vibrations couple all the way to the mirror through a pair of rubber tubes (1cm in diameter, 2m in length) and a...
5. ### Mechanical vibrations: maximum velocity

So I am almost sure I know how to solve this, just curious about the maximum velocity. Anyway, if you could double check my calculations, here it is. $T = \frac{t}{n} = \frac{10s}{15} = \frac{2}{3}s$ $\omega = \frac{2\pi}{T} = 2\pi \frac{3}{2} = 3\pi$ a). position at $t = 0.8s$...
6. ### I Frequency of Undamped Driven Oscillator near Zero

Description of the Problem: Consider a spring-mass system with spring constant $k$ and mass $m$. Suppose I apply a force $F_0 \cos(\omega t)$ on the mass, but the frequency $\omega$ is very small, so small that it takes the system, say, a million years to reach a maximum and to go to 0...
7. ### Find the resistive constant in a critically damped system

Homework Statement This problem is taken from Problem 2.3, Introduction to Vibration and Waves, by H.J. Pain and P. Rankin: A critically mechanical system consisting of a pan hanging from a spring with a damping. What is the value of damping force r if a mass extends the spring by 10cm without...
8. ### Vibration of a mass connected via preloaded spring

The setup: I have a mass (m1)connected to a much, much larger mass (m2) via a preloaded spring. They start out in contact because the preloaded spring holds them together. Now suppose the large mass is subject to vibrations, possibly at the resonance of the structure. Will the two masses...
9. ### General Question about Vibrations

Hello Everyone, I conducted an experiment with a metal beam which had a motor attached to it in with an eccentric mass on it. The two ends of the beams were fixed with a roller and a hinge(as I remember). This was a one degree of freedom experiment. I had to collect data during free/forced...
10. ### I A common 2nd order ODE from dynamics but...

Consider a simple single degree-of-freedom (SDOF) spring-mass-dashpot dynamic system with spring rate k, mass m, and viscous damping coefficient c. Dimension x is the absolute displacement of the mass. The base input translation is y. A dot notation indicates differentiation with respect to...
11. C

### 2-DoF system characterization with 2 dual axis accelerometers

I've been having some trouble with this problem for a while. (Its not a homework or coursework problem) Its a part of an experimental set up that I'm building and this is a simplified version of it. I have a rigid rod which is hinged at a point and can pitch or heave about that location. There...
12. ### I don't understand the derivation process here, help?

Homework Statement I understand the derivation it showed that included the sin (15.7 in the image) I just don't understand the following (15.8 in the image). Does "t" get pulled out of the equation? If so what do we derive for then? Does it become 0? If so, it would remain 0 and sin(0) is just...
13. ### Can I use symmetry in modal analysis in FEA

I am doing FE analysis for symmetric shape in boundary conditions and geometry, I would like to know if I can use symmetry in my analysis or not. I have tried to run trials, the results are very similar but I am not sure if this just a coincident
14. ### Simulation of Dynamic Charateristics

I have an assembly (a cuboid shaped structure). The vibration test data of this structure is available with me. I want to study the effect of vibration generated by a system mounted on top panel on another system mounted on same top panel. In order to complete this, I have prepared the FE model...
15. ### Automotive Random Vibration and PSD spectrum profiles

I am starting work on structural durability area for after treatment systems and deal with Random Vibration and PSD profiles quite often. However there are few fundamental questions about PSD profiles that I could not get answer to after a lot of search on internet. So finally decided to write...
16. ### I What does it mean for a particle to vibrate?

I intuitively understand macroscopic vibration, but trying to understand what it means for a particle to vibrate doesn't seem to make sense from the classical understanding I have of momentum and energy. First, are particles even said to vibrate or have vibrational energy? If so, how is momentum...
17. ### Vibration in "cantilever" rotating bar

Hi. I'm working in the design of an auotomatic bar feeder for a CNC lathe. I've established that the bars will not be longer than 1.2 m and will not have a diameter of more than 75 mm. Suppose they are steel bars, which would make them have a mass of about 80 kg So, bars are tightly held in one...
18. ### Vibration/noise cancellation

Hello gentlemen! So I have a situation. Concrete floor (ceiling actually) slabs like these has many cylindrical spaces in it. And noisy neighbors on top! The slab receives shocks / impacts and human shouts. First I found Tuned Mass Damper. It is good for continuous vibration but not for first...
19. ### Resonance frequency

I wonder of the air has resonance frequency or not, if yes what would happen if we excite it at this frequency
20. ### Peak-hold equivalent amplitude for transient vibration

I have a question regarding transient vibration data I received that was processed into a peak-hold equivalent amplitude (units = g). I have come across peak-hold before which is a type of "averaging" that retains the highest values from each estimate in random vibration overlap processing and...
21. ### A Free damped vibration of a system of 2 dof, demostration

Hi,I need help please, i want to know how to solve de differential equation of a system of two degree of freedom using Heigenvalues or Heigenvectors or if I can use any another way to solve this kind of equations.
22. ### Boundary conditions of that beam.

Hi all! I have to calculate the natural frequency of the system. Any idea of boundary conditions of this case? There is beam supported by two springs on the left side.
23. ### B Unable to explain the sound

In our apartment, for the last few months, my wife and I are being puzzled by strange sounds coming from the dining area while we remain in the bedroom at night. The first time we heard, I was quiet. Then my wife said, "Did you hear that?" So, it was no hallucination whatsoever. It is a distinct...
24. ### What is this and where can I find a replacement

The square seat (?) for the accelerometer has started to fall apart and I need to find a replacement for it. If this helps, the accelerometers are placed equidistant apart from each other, and the tester hits it - the cantilever beam - with a mallet to simulate vibration. Please refer to the...
25. ### 2-DOF problem with unknown stiffness and velocity

Homework Statement I have a 2-DOF system, whereby I have one body that is grounded by a spring (body A), and a second body (body B) attached to the first by a spring and a viscous damper. For body A, I know the velocity and amplitude (before body B is added). I think I also have the stiffness...
26. ### B Would time slow down tied to a nuclear-powered oscillator?

I've always wondered this. Let's say we're not limited by the type of vibration, e.g. if choppy vibration doesn't constitute continuous movement, then some sort of oscillating vibration.
27. ### Frequency of Vibration of a water tank

Homework Statement Assume that there is a tank on a 200 ft pedestal type support. When full the tank and contents have a weight of 50,000 lbs and it is never drained to a point where the tank and contents have a weight less than 20,000 lbs. Assume the pedestal weight is negligible compared to...
28. ### Find the frequency of the cylinder's vertical vibration

Homework Statement Homework Equations w = √k/m w = 2π/P ƒ = 1/P The Attempt at a Solution I feel like I'm so close to the answer, I think it has something to do with the fact that there's a spring and pulley in the system that is throwing my answer off. I have √k/m = 2π/P So, P =...
29. ### Is sound a renewable energy or non-renewable energy?

I've been searching the web for this answer and can't seem to find it anywhere. Can anyone help me? Is sound a renewable energy or non-renewable energy?
30. ### Solving boundary conditions for vibrating beam

Hi there, I'm solving the equation for the transverse vibrations of a Euler-Bernoulli beam fixed at both ends and subject to axial loading. It's a similar problem to that described by Rao on page 355 of his book "Vibration of Continuous Systems" (Google books link), except the example he uses...