Vibration Definition and 475 Threads

Say someone hits an iron block in space with a metal hammer, causing vibration. Will vibrations in space keep vibrating forever? To my understanding vibrations stop vibrating on Earth because the object vibrating sends the energy into the air which takes that energy away from it. Since...

Hello Every one, When I am looking at the design of a vibration screen, I found that the claims from different source have different equation. Please have a look on the attachment. You can see "Claim 2 " is a more general approach but need to know spring constant k. while "Claim 1"...

I roughly understand that when we hit a metal rod right into the end will excite longitudinal vibration in the metal rod, and the place we hold will be a node. the position i hold will kind of determine the frequecy of the ringing sound produced. Is that right? But what will happen if we hit...

Pls help me to solve this..

I designed a spring and mass system (damping unknown) that is vibrated by applying a sinusoidal force to the mass using an electrodynamic shaker. The mass is estimated to be 100 Kg. The spring is actually 4 springs, each with a k value of 63.55 N/mm, supporting a platform (one spring at each...

Does anyone have a graphic example of underdamped vibration?

Does anyone have a graphic example of beat vibration?

I posed this thought experiment elsewhere, so the tone may seem a bit odd. It's based on what I've been reading on physical chemistry, atmospheric radiation and thermal physics. Just wondering if my interpretation is on the money or if I've made any incorrect assumptions. "Time for another...

Mods, I hope I'm not breaching any guidelines here, haven't had any responses in General Physicsand thought perhaps the question might be more at home here. I understand that CO2 molecules absorb infrared at 2.7, 4.3 and 15 microns, this makes them become vibrationally excited (rocking...

I understand that CO2 molecules absorb infrared at 2.7, 4.3 and 15 microns, this makes them become vibrationally excited (rocking, stretching, bending, I don't know all the modes). I have a few questions from this point: 1. When the CO2 molecule re-emits that energy is it obliged to do so...

1. A rigid uniform slender beam weighing 8kg is hinged at A and is in dynamic motion. A spring of stiffness 4.5kN/m and a damper giving a viscous resistance of 35Ns/m is connected at B. The beam carries a flywheel of mass 28kg at a distance of 0.9m from A. The beam, AB is 1.2m long, Find the...

How does this tiny generator work? http://www.engadget.com/2007/07/06/tiny-generator-turns-vibrations-into-electricity/

Mechanical ad Electrical vibration EASY question please help? In Boyce and Diprima textbook it says that: mu'' + ku = 0 . Then it says the general solution of this is: u = Acos (w^2)t + B sin (w^2)t , where w^2 = k/m It provides no explanation how it arrives at this. Where does...

Homework Statement I am asked to provide an anti vibrational support mount for equipment mounted on turbo-prop aircraft. The equipment has a mass of 40kg. the vibrational response of the equipment to the environmental disturbances will need ot satisfy a safety limit prescribed by the...

1. A mass attached to the lower end of a vertical spring causes the spring to extend 25mm to its equilibrium position. The mass is then displaced a further 20mm and released. A trace of the vibration and time measurements are taken. From these measurements it can be seen that the displacement...

Homework Statement The solution to the Initial value problem, x''+2x'+5x=0, is the sum of the steady periodic solution x_sp and x_tr. Find both. Homework Equations The Attempt at a Solution I already found x_sp ( the particular solution). It is (-44/533)cos(7t)+(14/533)sin(7t). r^2+2r+5=0...

need a tutorial on how to model piezometric material in ansys.. i am working on a project related to piezometric control of vibration..please need it very urgently!

When we have vibration excitation then the radius of nucleus is define like: R=R_0[1+\sum^{\infty}_{\lambda=0}\sum^{\lambda}_{\mu=-\lambda}\alpha_{\lambda\mu}Y^{\lambda}_{\mu}(\theta,\phi)] where \alpha_{\lambda,\mu}=\alpha_{\lambda,-\mu} and \alpha_{\lambda,\mu}=\alpha_{\lambda,\mu}(t)...

Hi, I am a bit confused about somethings. I want to determine the mode shapes of a free-free beam. I assume that I can use the following? 1. the Euler-Bernoulli theory 2. the generalised wave equation 3. modal analysis With modal analysis I can use the eigenvalue problem to finally...

If the light move from left to right, what's the vibration direction of light wave? up-down or front-back or some other ways?

Hi.. I'm trying to do the damped vibration analysis of a cantilevered beam. Although i am choosing no damping in subdomain settings menu, it solves the problem as if the material is damped (the result is a damped vibration signal). Is this is a bug or am i missing something? Thanks in advance

Hello MechEs (or anybody else who'd care to reply) I'm about to get a small, but fairly sensitive analytical scale recently (down to 0.01 mg) and now I'm trying to figure out a way to dampen ambient vibration from the room and its surroundings (people walking around, HVAC, etc.) I've got a...

1.A 2-meter long wire vibrates with a frequency of 330 Hz when the tension is 500 N. What is the new frequency if the tension on the wire is doubled? i have no idea how to solve this,, help..

Hi all, I have a question, I am trying to do to measure the stress on human feet while standing on a vibrating platform. The platform was placed on top of a cam and the cam was driven by a motor. I know most of the parameter, i.e. frequency, speed, acceleration but how can i calculate the...

hi all.. How can i describe initial conditions or initial forces in comsol(like wave forms such as ramp or parabolic)? I couldn't find it in the manual. in ansys, i do it in time steps(in solution options).(like t=0, F=10 t=0.001 F=0) I tried to give initial displacements to the points but...

Homework Statement The slender rod AB of weight W_{AB} is attached to two identical collars, each of weight W. The system lies in a horizontal plane and is in equilibrium in the position shown when the collar A is given a small displacement and released. Calculate and plot the period of...

Homework Statement Determine the max and min values of x and their times from 0 to 2s initial conditions X0 = 0, V0 = 1m/s http://img266.imageshack.us/img266/2198/figure1.jpg Homework Equations Undamped force vibration: m\ddot{x}+kx = F0sin\omegat Damped force vibration: x =...

How fast does an atom vibrate in m/s. I have found how fast it vibrates in hz but I'm trying to convert that to speed. Thanx.

1. SDOF Systems Governing Equation m(dx^2/dt^2) + c(dx/dt)+ kx = F(t) how do i get this equation below? Free Critically damped Vibration x(t) = e^(wt) [x(0)(1+wt) + (dx/dt)(0) t] (dx/dt is x with 1 dash on top)

Homework Statement A child on a playground swings through a total of 42 degrees. If the displacement is equal on each side of the equilibrium position, what is the amplitude of this vibration? (Disregard frictional forces acting on the swing) The Attempt at a Solution I know amplitude is the...

Does anyone know of any really good resources on high turbulant flow/velocity induced vibration in piping systems (in particular this is a very high flow PSV off of a large vessel and they are concerned with dramatic pipe vibration when it relives) also it would be nice if the recommended...

an astronaut in space sits on a chair that vibrates horizontally at the end of a spring. the spring has a 1200-N/m spring constant, the amplitude of vibration is 0.50 m and the speed of the chair as it passes through equilibrium is 2.0 m/s. also devise another method to determine the mass, you...

Hey, so I just ripped the two permanent magnets out of an old seagate hard drive, and have a breadboard for my electronics class to practice with logic chips, and figured id wrap some wire around one of the magnets and see what happens. I got around 10 turns of the wire about the magnet, and...

I Have been studying a problem involving a two mass/spring system. I have been analysing the system and finding out the frequency at which the vibration of Mass 1 is absorbed by Mass 2 and spring 2. The problem can represent a quarter car system where Mass 1 is the unsprung mass (wheel...

Homework Statement Known : - Material : Tungsten - Property : G7 - Drill, you can see the picture in here : http://www.accuromm.com/drills.html" - Other information you can find here : 1...

so u = -cos(t) + sqrt(3)sin(t) so the Wo = 1, and R =2, but how do i find delta? tan(del) = sqrt(3)/-1, but the answer has it as u = 2cos(t-2pi/3) i can't get the 2pi/3 no matter what i do... thanks

if we have a machine is running at 6,000 rpm. It is vibrating at 1 mil Pk-Pk. Calculate the velocity & acceleration of the vibration in mm/s & mm/S2. Explain the calculation. can anybody provide me the formulas?

Hi, I have a simple question to ask: What is the Eigenfrequency mean in vibration? I am confused and can anyone here explain to me or provide me some useful link? I am trying to use comsol to analyse the vibration frequency from a plate, which was mount on top of 4 camshafts. These...

Homework Statement in this vibration system find ratio of (m/m1) so that (point A) would not move and will stay stationary. point A distance from left end of spring is 0.25 of total length of spring. all surfaces are frictionless. the problem is in indie numbers: The Attempt at a Solution...

Hi, Can anyone recommend a text for Vibration. My university recommends Mechanical Vibrations by S.S Rao but it has received bad reviews. I am an undergraduate in my second year and prefer the sound of a book that makes this less complicated...? Thanks Will

Hi, Suppose we have a fixed-fixed beam with a distributed force acted in between -on a part of the beam. I have found out the fundamental mode of vibration i.e calculated the fundamental resonant frequency of the above case. But there will be higher order mechanical modes too.. In case...

Hi.. I have a question about natural fvibration. Every object has natural frequency and modes of vibration. Let us consider a simple cantilever beam for our discussion. and Let's say its first 4 modes of vibration are at 3, 6, 10 and 20 kHz respectively. (I made up these frequency values)...

Hi All, I need some basic info of He closed cycle cryos..(like working principle, etc).. I have a compressor, which compress He gas and passed into a cryo's coldhead. So He gas expands in side the coldhead and cools the coldhead..then it again passes into compressor..so the cycle repeats.. I...

[b]1. When seven people whose average mass is 83 kg sit down in a car they find that the car drops down 0.87cm lower on its springs. Then they get out of the car and bounce it up and down. The acceleration of gravity os 9.8m/s^2. What is the frequency of the car's vibration if its mass (empty)...

A string of length 0.29 m is fixed at both ends. The string is plucked and a standing wave is set up that is vibrating at its second harmonic. The traveling waves that make up the standing wave have a speed of 115 m/s. What is the frequency of vibration? fn=n(v/2L) I tried...

I'm looking for an in depth and comprehensive treatment of the theory of normal modes; any suggestions?

helo guys,i'm new here hope to gain knowledge from this forum.i currently doing a project about design of turbofan engine.now i have to do preliminary stress and vibration analysis for the turbine blade.i'm not very good at stress and vibration and have search the internet about it but couldn't...

Homework Statement A parallel plate capacitor is used as a vibration sensor. The plates have an area of 100cm^2, the dieelectric is air, and the dist between the plates is given by d(t)=1+.01 sin(200 t) mm A constant voltage of 200 V is applied to the sensor. Determine the current...

Homework Statement A vibration platform oscillates up and down with an amplitude of 10.4 cm at a controlled variable frequency. Suppose a small rock of unknown mass is placed on the platform. At what frequency will the rock just begin to leave the surface so that it starts to clatter...

Please could anyone help me on the topic "Controlling the vibration and shocks received by elctronic-mechanical components"?