Vibration Definition and 475 Threads

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...

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...

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...

When finding the fundamental for thin bars, the approximate equation (http://hyperphysics.phy-astr.gsu.edu/hbase/Music/barres.html) only refers to the length and thickness when calculating. I'm trying to figure out the frequency and node location along the length and width of the fundamental...

Homework Statement When unfingered, a string on a guitar vibrates at 627 Hz. What frequency will the string produce when fingered one third of the way from the end, that is only two thirds of the string can vibrate? Homework EquationsThe Attempt at a Solution I am not too sure what equations...

I really liked this book but the problems don't have answers at all (not even numerical one's at the back of the book). There is not even a solution manual to download or buy online. How am I supposed to use this book otherwise?

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...

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...

I am working on some acoustic synthesis models of real world instruments. The Bessel Function zeros give the vibration modes of a circular membrane, which can be used to model a drum head or even roughly a cymbal. However, much of a drum's sound (especially snare) comes from the "ring" of the...

Hi all, been a while since I studied physics but I saw something that I found strange, This device: https://researchfrontiers.uark.edu/good-vibrations/ from University of Arkansas A free floating graphene sheet extracting energy from brownian motion and converting that to electric current...

why are molecular vibrations never synchronized in a way that would make them macroscopically observable?

Hello i have asd value of 0.015 g2/hz and freq range of 1 to 100hz. How to select a damper for isolating my equipment from the above mentioned vibration?

Homework Statement Homework Equations a11 = a21 = a31 = a12 = a13 a22 = a32 = a23 $$ \begin{bmatrix} x_{1} \\ x_{2} \\ x_{3} \end{bmatrix} =ω^2m \begin{bmatrix} a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33}...

I have been thinking about the Higgs field and how things interacts with it. I thought about why photons for example does not interact with it while quarks does. It could be because of the size and if when a particle is a certain size it will interact with the Higgs bosons and then slow down and...

Good afternoon. I am currently attempting to build a circuit for my university dissertation. I am looking to build a cct that would use an accelerometer to sense vibration from say a gearbox of a helicopter to a storage device before being transferred via Bluetooth to a laptop. My questions are...

Hello. I need some help for my HW. I've been trying this particular problem but I don't know if I am on the right track. The problem and my progress in answering the problem is down below.

Homework Statement Hello there, I thought a fully analog , cutting vibrational shapes on steel plate and hit to each shape by fingers and produce whichever sine , square , triangle vibration you want and filter of those collections of vibrations by another steel cut shape and make a synthesizer...

Homework Statement How can one reduce the vibrations entering the house? And why do certain sounds vibrate more in certain place, but quiet fown if you move a bit further away. Homework EquationsThe Attempt at a Solution I was thinking it's something to do with the fact that sounds wave are...

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...

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...

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

Homework Statement A rectangular cantilever beam of length L and side lengths b with negligible mass is attached horizontally to a wall. A mass m is attached to the end of the beam where a motor is also located. The motor applies a force on the end of the beam described by the equation...

Interesting new jet plane has rolled out of its hanger. https://img.purch.com/h/1400/aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzA2Ni80NjMvb3JpZ2luYWwvZHJvbmUxX3dlYnNpdGUuanBnPzE0OTYyNjgyNTY= It looks like there are vibration modes of the plane that during normal operation would shake the...

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...

I have developed a mathematical model to study the dynamic behavior of rotor (with 6 dof). It is assumed that rotor is rigidly mounted at the mid point of shaft, and both end of the shaft is attached to ball bearing. I have developed the FE model for it too, and the frequencies in X, Y, Theta...

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...

Homework Statement Two masses ##m_1## and ##m_2## are joined by a spring of spring constant ##k##. Show that the frequency of vibration of these masses along the line connecting them is: $$\omega =\sqrt{\frac{k(m1+m2)}{m1m2}}$$ Homework Equations ##x(t)=Acos(\omega t)## ##\omega...

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...

Homework Statement [/B] "Absorption spectra of gaeous HCl show a line at 3.5 μm which results form molecular vibration (oscillation from interatomic distance)" How do I get the frequency of vibration from this? Homework Equations ? If I knew this, then I could probably solve the problem The...

Hi, I have just started reading of "finite element model updating" which is a statistical means of updating the finite element model when there is source of uncertainty in the modelling parameters, modelling error, etc. My question below is NOT related to finite element model updating but to a...

Homework Statement The uniform rod shown has mass 6 kg and is attached to a spring of constant k = 820 N/m. End B of the rod is depressed 10 mm and released. Determine the period of vibration. Picture is attached below Homework Equations Fs = kx W = mgThe Attempt at a Solution I honestly...

When we say that a phonon vibration mode has an average energy <E> are we saying that all atoms (or harmonic oscillators) in a piece of matter (eg. a nanoparticle) will also has that energy, or that the piece of matter as a whole will have that energy ? In the second case the amplitude of the...

It has been stated in previous threads that engine inefficiencies are caused by: Pumping losses (induction and exhaust) Frictional losses (in bores, bearings, and ancilliaries) Thermal losses to exhaust, coolant (jacket, charge and oil), and surroundings Does engine vibration have an effect on...

I am trying to calculate natural frequency for torsional vibration of fixed fixed beam using following formula. =1/2*3.142 sqrt(K*g/mr^2) hz Where K=J*G/L and G=Modulus of rigidity g=acceleration due to gravity=386.4 in/se2 m=mass hanging on the beam at distance 'r' from the longitudenal...

So I'm trying to understand how the modulus works in metals. I understand that when the temperature rises, that means that the modulus decreases. But I do not understand exactly what it is or how it affects the way that the molecules would vibrate for instance, as kinetic sound energy moved...

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...

Hello Everyone I have got a question concerning the calculation of the overall energy input in random vehicle vibration tests. I have got different power spectral density levels for different random vehicle vibration tests and would like to compare them with each other concerning the overall...

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...

Homework Statement We have a square membrane and a circular membrane, both fixed from the edges. They are made of the same material with a surface mass σ , and their surface tension is T. We want to tune the lowest eigenfrequency (the fundamental frequency) of both membranes to the same...

Homework Statement Consider a small cluster of four copper atoms. Assume, that each atom can oscillate around its equilibrium position independently of the other atoms. Let us model each direction of vibration as a harmonic oscillator, whose energy is quantized Evib = ¯hω(n +1/2), where ω =...

Consider a mass m with a prestressed pull spring on either end, each attached to a wall. Let k1 and k2 be the pull spring constants of the springs. A displacement of the mass by a distance x results in the first spring k1 lengthening by a distance x(and pulling in the - direction), while the...

Homework Statement Find the free vibration of the bar supported by a spring and a viscous damper (See attached figure) Homework Equations (a)Derive the equation of motion (b) Obtain the moment of inertia of bar (c) obtain natural frequency when d=0. The Attempt at a Solution

Trying to build a case for a belt driven ball screw axis versus a Planetary gear box, with the fact that the motor vibration would carry down the gearbox to the axis, but the timing belt drive would isolate the motor vibration. How would I model this? and ideally a way to get a factor of...

Hello i was looking at the damper CR3-100 as seen in the pic. Howver from the tech sheet given i cudnt make out what's the cutoff freq of this damper...i mean which is the frequency beyond which it doesn't let the frequency pass...what to make of this KN/m value?

I wonder of the air has resonance frequency or not, if yes what would happen if we excite it at this frequency

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...

Hi,I need help please, i want to know how to solve de differential equation of a system of two degree of freedom using eigenvalues or eigenvectors or if I can use any another way to solve this kind of equations.

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.

Hi everyone, i facing a problem which is the ansys simulation setting problem. I had use modal analysis simulate and get the result. But the problem is the result for three axis which is x, y and z axis also have same value for the frequency. Is that any setting i missed up?

hello I'm a belgian wine maker. We play music in our wine celler (with a very powerfull baffle) because it creates small vibrations on the tanks. Thanks to this we mix he wines less and so they keep more aromas . I would like to get more "powerfull" vibrations. Does somebody have an idea of how...