Vibration Definition and 475 Threads

Hi... I am leanring some knowledge about vibration. For a given vibaraiton system, for example, cantilever beam, we can perform modal anlaysis and found five natural frequency of 3, 6, 8, 10 and 20 Hz (just made up) and five corresponding vibration modes. after that we give a harmonic force on...

I have created such vibrating feeder model on SW but on ANSYS I'm only analyzing the frame. 1)How do I set up boundary conditions, I think I need elastic supports? 2)In modal analysis I have elastic, fixed supports, remote displacement - which should I use and in what directions? 3)Do I perform...

If my assumption is correct, Particles are vibrating is some repetitive way which can be charted as a sine wave on a graph. If you start at 0, go up, then down below 0 then up to 0 again you have completed a "cycle." The rate of cycles is known as Frequency. Does Velocity and/or Gravity affect...

Hello. I have to do an analysis for my thesis. It's about "free vibration of I section beam, composite material". I searched it on the internet but i did not find an appropriate thing. I can do the analysis about it but i must compare the results. So, is there anybody help me about it?

Hi, my level of knowledge of string theory is the following : I understand that to each elementary particle there corresponds a string vibrating at an associated frequency (mode). So my questions are : 1. Is there some table yet that proposes a correspondence? Such as : electron : so many Hz...

can we find the harmonic of vibration somehow just by knowing frequency?

HI, I am studying vibration, came across this in a textbook and can't see the steps taken to substitute e.q 3.5 into 3.3. There is a second derivative x so where does this go, as there is no s^2 either and I can't see how cos was eliminated Cheers

Hi, I just started an introductory class on Mechanical Vibration and would like to know what's a good book mainly with good problems so i can practice. To be more clear the topic discussed here ->...

Hi there! Im trying to do an analysis in Abaqus of a cantilever pipe, with a tip mass at the free end, that is decelerating to a stop at 10 m/s2 from 10m/s, causing it to vibrate. To validate my results I am doing some handcalcs. I have done a static analysis and calculated the maximum...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Okay, I am having trouble with the units. I have the values for the wavenumber and I am trying to find the period. These are the formulas that I am trying. T = 1/f ; f = c/lambda example...

Hi, I have previously made a post in order to gain some insight in my rather out of control project. Long story short I am investigating vibration of a circular plate and its standing waves. After consultation at this forum I have been guided in the direction of acoustics and bessel functions...

So, here's the set-up: A small stereo speaker is connected to a function generator. A concave lens, bearing a ball is place over the speaker. Now, the frequency is slowly increased in the function generator. My question is, Will the ball really bounce at a certain frequency? Because I am not...

Hi everyone. I'm wondering if vibration (likely acoustic) could be used to achieve a uniform suspension of an insoluble solid within a liquid solution? It seems completely reasonable to me, but I'm unable to find any information on the topic. I'm planning on getting in a lab to test it soon. Can...

I've found several accelerometer apps for smartphones (for example http://www.iseismometer.com and http://www.now-instruments.com/products/3-vibsensor ). Are these useful for doing quantitative vibration analysis, and if not, what are their deficiencies?

Hi guys, I'm new to this forum and this would be my first post :-) Hope you guys can guide me on what to do on this alternator that's having problem with vibration. I'm running out of ideas now on what to do with this alternator. The alternator was sent to our workshop by the client for...

Homework Statement three harmonic function of frequency p, 2p ,3p were added together. what is the frequency of resultant periodic function? Homework Equations X=Asin(wt) A-amplitude w-frequency X=X1+X2+X3 The Attempt at a Solution need a hint ..

Hi There, I have a VTS(vibration test system)-100 shaker. To make sure it works correctly, I have done a acceleration frequency response test for the bare shaker. In which, I place an accelerometer on the top of the shaker platform, use a function generator and amplifier to drive the shaker at...

Just a general inquiry, and not for any personal gain and or theory, I would like to know if anyone has developed a formula for measuring the vibrational rate of an atom.

Homework Statement Rigid body with one spring. Homework Equations Torque equations ( M=I * "alpha") The Attempt at a Solution So I think I can solve this problem but there is only one thing I do not understand. When I am writing my torque equation I would think that the weight of the bar...

Homework Statement A half-full water tank mounted on the top of a building is modeled as shown below. Find the shear force it can produce? m = 500 kg k = 1000 N/m model: https://app.box.com/s/qke2kbwag2mp9a23kkqq Homework Equations Transfer Matrix Method: Point & Field Matrices...

Hello everyone. I'm trying to find out if there is any software that is utilized by engineering firms to analyze and process accelerometer data. Ultimately, we had instrumented a product and acquired data. Now we would like to view and compare the data so we can select the best samples then...

Homework Statement http://i.imgur.com/wJu0AEs.jpg http://i.imgur.com/J9sEWgq.jpg?1 Homework Equations Kinetic Energy = T = 1/2 * I * (theta_dot)^2 Potential Energy = V = 1/2 * Kt * theta^2 The Attempt at a Solution Matlab Code and Results: >> I1=3600; I2=200; I3=800; I4=4800; d1=0.15...

Hello everybody , I am student in mechanical enginnering. I have to evaluate the solution Fe-Safe. i am working on two subjects: Harmonic and PSD Vibrations. The modal analysis are done in Abaqus. I would like to understand how Fe-Safe computes Life Fatigue in case of harmonic analysis. What...

Hello, I am studying and trying to understand Powertrain / Engine mounts used in automotive such as these: http://images.gasgoo.com/MiMwMDRfMDA0Izc4MDA3NzIwMA--/auto-part-engine-torque-strut-mount-engine-mounting-for-buick-enclave-chevrolet-traverse-gmc-acadia-25840458.jpg...

Homework Statement y(x,t) = (9.00cm)sin((5Πcm-1)x + (3Π rad/s)t - Π/8) There are 11 parts, and I have answered the first 10 (they include velocity of a wave, amplitude, all that good stuff), but I haven't seen anything in lecture or in the textbook that mention finding maximum vibration speed...

Homework Statement a.) Find the total energy of vibration of a string of length L, fixed at both ends, oscillating in its nth characteristic mode with an amplitude A. The tension in the string is T and its total mass is M. (HINT: consider the integrated kinetic energy at the instant when the...

Can somebody please tell me what should be present in the free body diagram for this system below. Also please mention the arrow details like which direction each force in the free diagram should be acting in. I really need to understand this concept...

Let us imagine that there is a Massless spring with fixed at one end. Unloaded length = L Spring constant: = k Mass = 0The spring is at static Equilibrium Force: F Displacement: d F = k d, elongated length: L+d If I remove F, what will happen ? 1. Spring return to...

Hello! I want to ask about spectrum of Ac induction motor, first of all, we measure points at non drive end + drive end - radial+axial direction. At horizontal direction we measure not only velocity but also acceleration. Two questions: 1. I see a peak around 65000 rpm with sidebands at...

So the equation to obtain the frequency of the modes of a square membrane is something like ω m,n = ∏ [(m/a)^2 + (n/b)^2]^(1/2) This equation can be used to get the frequency for Modes such as (2,1) and (1,2). How do I get the frequency for such modes as (2,1)+(1,2) and (2,1)-(1,2) ...

Why are we not supposed to operate a machine on its natural frequency condition? I read max. energy transfer happens at this condition. What exactly does it mean? When we swing a pendulum it just oscillates on its natural frequency. Nothing goes wrong there. So what makes it different for a...

I've just got a quick question that hopefully someone can answer. My question is - why does the membrane in COMSOL vibrate without you telling it to? Here are some specifics if required... In COMSOL here are my setup details: - Physics: (3D) Structural mechanics - Membrane Study...

Hi Folks, I am trying to replicate a solution in Matlab for the following problem ##\displaystyle \ddot x + \frac{k}{m}x = \frac{F_o}{m} \sin w_ot## using 2 first order linear differential equations in Matlab as shown below tspan=[0 4]; y0=[.02;1]; %Initial Conditions for y(1)=x and...

Homework Statement I'm following a procedure in a particular paper as part of my Masters project. The paper is called 'Theoretical investigation of the sound attenuation of membrane-type acoustic metamaterials - Y Zhang, J Wen, Y Xiao, X Wen and J Wang (2012)' and can be seen...

Hi, So basically I am wondering how can you increase damping within a part, just by altering its geometry. I've researched this topic, but haven't yet found anything significant. Here are my main findings: - Rayleigh Damping uses the equation: [C] = α[M] + β[K], which to me shows that mass...

Hello all, I'll start by explaining that this is my first post, and I have very little engineering and mechanical knowledge. I am currently completing my phd in neuroscience so the purpose of this post is to seek information to indulge in some of my hobbies :) I am designing a machine...

dear all, I am working on a problem about the vibration of a piezoelectric ring with electrodes on the upper and lower surface. the coordinate system is cylinder coordinate system. the structure is shown below. This is an axisymmetry problem. the polarization of the piezoelectric ring is...

Can anyone help with the following - which I have been musing about for some time. mThe general idea is that when heat is applied to a substance the molecules / atoms in that substance vibrate more and more (until the bonds in the molecule break). OK - so can anyone help with the following...

BTW, exist some substance that when is mixed with nitrogen, or with some compost of nitrogen, reacts and explodes? Also, exist some compost of nitrogen that when is submitted to high vibration or shock reacts and explodes?

Homework Statement A liquid (density ρ) is poured into a bent tube such that the two halves of the bent form angles α and β with the horizontal. The length of liquid column is l. If one of the liquid levels is depressed and released, the levels begin to vibrate. Find the period of vibration...

Good Afternoon, all... I design professional pitching horseshoes. I am trying to determine if the method used to mount the stake in the horseshoe pit affects the recoil of the stake when a horseshoe hits it. A stake that loosens over time will reject a horseshoe more readily than a solidly...

What does a first / second / nth order frequency mean physically?

Hi, I'm currently studying Mechanical Eng & have a class next semester 'Eng Analysis', which involves a large section on vibration. I've been trying to work my way through S.S.Rao, Mech Vibrations, 2nd edition. There's one specific problem; Project 5.51/Chapter 5/page 292. The problem concerns...

Homework Statement Middle C on a finely tuned piano vibrates 262 times per second. What is the period of the wave? Homework Equations T =1/f The Attempt at a Solution Im just really confused.

what is the difference between vibration, oscillation,simple harmonic motion and periodic motion?Is there any similarities between these terms? can anyone explain clearly pls.

I am doing a project in controlling the vibration in 4 wheeler exhaust system by using dampers. But i am not sure of what kind of dampers to use. Also is it possible to add multiple dampers and one just near the exhaust manifold.

Hi there! Just as a disclaimer before I start: I am new to physics and new to these forums, so please be kind if I say anything that seems silly to those who know more than me on the subject. :) I've been looking at this old thread about the human body and frequencies, linked below, due...

Say I have a mechanical device like this one: If I plot the acceleration profile at (trace-) point D I get something that looks something like this: Now, here's the question: Can I build a device composed of one of more (eccentric rotating mass) vibration motors that when rotating...

Hey guys, I'm working on solving a problem of figuring out what an impact velocity is going to be roughly. The numbers seem very small to me though so I was wondering if you guys could check out my work. This isn't a homework problem, but rather a real problem. I"m trying to build a test...

Does skin vibrate at the molecular level? If so does it have a steady frequency? If so would it be possible to use a laser to detect said vibration from a distance?