Vibration Definition and 475 Threads

I just wantedhow the atoms vibrate in solids. I do not want to know the reason of their vibration (I know it). I just want to know their pattern of vibration. Some people say that they vibrate by undergoing a to and fro motion. But I do not think it is true because the objects are three...

Hi All, I have a thought that I had a while ago and wanted some advise/feedback etc My thought was as follows: All atoms have their own specific vibration, if one was able to match this vibration or its oppisite then the bonds that hold this atom together would break apart. Kind of...

Homework Statement Hello, I did the following measurement: A piezo element (mass approx. 50 gram) is fixed onto a vibration shaker The force exert on the piezo, 0,124 N (rms) is measured with an impedance head The vibration frequency (sinusoidal signal) is 142,4 Hz The acceleration is...

1.I am busy with an assignment based on a Vibration experiment in a Mechanical Engineering degree program The procedure is documented in the lab handout and one part is to compare the measured natural frequency to the calculated natural frequency The formula given in the handout for natural...

Hi, everyone. I'm required to complete an open ended analysis of the following problem: http://imagefrog.net/show.php/146581_image.png http://imagefrog.net/show.php/146581_image.png I'm not requesting a solution, I'm only looking for assistance in relation to determining the spring stiffness...

I wish to dampen a boom arm, which at its fixed point is connected to a vehicle (arm length is 5m long). The boom is 'L shaped' is attached to the to of the vehicle and extends 5m in the horizontal, then the second leg hangs down 5m, almost to the ground. The end of the boom arms contains lead...

1.0 Introduction As the thread title suggests, this is indeed referring to a lab experiment. I am not posting here to gain easy solutions to the lab manual questions, rather I'm posting here to gain knowledge on a subject I know very little about. Let me explain the lab experiment in detail so...

Homework Statement :[/B] BoB released from rest, L = 102 cm, theta = +-5 degrees, g = 9.81 m/s2 assume a SHM (I) Determine the angle theta after 1.6 s (II) Determine the magnitudes of velocity & acceleration of the BoB at 1.6 s Homework Equations theta = A sin (w t + phai) The...

1. Homework Statement : BoB released from rest, L = 102 cm, theta = +-5 degrees, g = 9.81 m/s2 assume a SHM (I) Determine the angle theta after 1.6 s (II) Determine the magnitudes of velocity & acceleration of the BoB at 1.6 s Homework Equations theta = A sin (w t + phai) The...

Place a guitar floating in the vacuum. Once one string start to vibrate it would not stop since there is no air and contact. So any object vibrating in the vacuum would continue to vibrate indefinitely or the energy would become heat and radiation?

Hello, I am a student making a generator. the main idea is to use the vibration with the magnet coil setting with the spring to generate electricity. I will use the permanent magnet, but i know that e = N w B A i decided to have a 12Volt output, constant vibration frequency in 100Hz the A...

vibration problem! Homework Statement Question:There is a fixed end beam PQ. It is carrying a motor M. The motor is unbalanced and when the motor is rotating ,it is making the beam to vibrate with a frequency equal to the speed of the motor. A small mass is kept at point A just above the...

I've attached the problem sheet with the given bottom line numerical answers. I'm struggling with question 3 part d and the solution sheet doesn't include the answer to this part of the question. I've completed the previous parts to question 3 already. Can someone please guide me through...

Hello PF users: I am looking to perform a fatigue and fracture analysis of a machine component subjected to a 2D vibration forcing function. I was hoping that it could be done on ANSYS 12 because I have license to use it but looks like the pre-processing could get very complicated. (I have no...

Hi, I am working on a case with a flexible cylinder with a flow of air inside and a cross flow of water. This is a fluid structure interaction case and the case is such that I can define the natural frequency of the air inside the cylinder and that would then be used to solve the structure...

I have a motor driving a gearbox. I had DE bearing of the gearbox replaced recently as pitting in the inner race was found. Before re coupling the two units, I had the motor vibration checked and found to have satisfactory vibration levels in horizontal, vertical and axial directions. After the...

Homework Statement I have a under-damped vibration equation (below) that plots displacement vs time graph. Thing is i need to plot an envelope of the graph and it has to take into account initial speed v0. Homework Equations 1. Equation which plots displacement vs time. x(t)=exp^(-zeta*Wn*t) *...

Hi all, My fellow students and i are working on a university project. We are making a fixture and doing some vibration testing. We purchased a few disk motors and we are attaching those to our fixture. The set up is fine and we have been able to get the motors running and been able to vibrate...

Homework Statement Two springs, each with unstretched length 0.200 m, but with different force constants k1 and k2, are attached to opposite ends of a block with mass m on a level, frictionless surface. The outer ends of the springs are now attached to two pins P1 and P2, 0.100 m from the...

Hi all I am struggling with going between various representations of vibrations in paticular the complex form. I am using Rao as my text btw so for a free vibration and making it simple no damping the euqation of motion is mx^{..} + kx = 0 with the general solution being x...

Homework Statement Hello, I would just like to make sure I am doing the problem correctly. What I have is a cantilever uniform beam that is fixed at one end and free on the other. Basically, it is a wing and I am using a lumped mass approach to find a graphical representation of the wing's...

lets say you build a capacitor heat engine that is made of two charged parallel plates. let's say one plate is hotter then the other and do to the thermal vibration one is moving more then the other. you should be able to convert the mechanical vibration to electrical current. now the question...

Hi, I need some help with an experiment: I have a cantilevered steel beam, fixed at one end and free at the other. When I excite the beam with forced vibration at the fixed end, resonant frequencies are evident. The first is at 10 Hz and the second is at 60Hz. Performing analytic...

Homework Statement I need to find the maximum speed of a hydraulic valve component which is attached to a vibration testing machine and subjected to sinusoidal vibrations. The values I have so far are the frequency of vibration, the period of motion, the acceleration amplitude and the...

I need to calculate the frequency of sinusoidal vibrations in simple harmonic motion. The only known values that I have are the acceleration amplitude and the vibration amplitude. Is there a way of calculating the frequency of vibration without knowing the period of the oscillations?

Hi all. Iam trying to find out an mass-damper-spring equations for a 1-DOF mechanical shaker for the purpose of plant model equation.Further, this equation is used in kalman filter algorithm with measurement model of an accelerometer. Can anyone help? Thanks in advance...!

Hi guys, in my company we have seen a lot a failures on a flange, in particular one flange screw strips. This flange is mounted in a vehicle and it support some hydraulic pipes. The designer thinks vibrations should cause the failure and so he suggests me to measure the flange acceleration along...

Dear all, Please help me with this interesting question on vibration absorber: A diesel engine, weighting 3000 N, is supported on a pedestal mount. The engine induces vibration through its pedestal mount at an operating speed of 6000 rpm. Determine the parameters of the vibration...

Hi everyone, this i my first post here. I need some help in doing a general work instruction for motor vibration analysis. I am totally new in this maintenance sector. I could do with some help :) Basically i need to know which exact points i have to test for vibration and method to be use...

Hello all. I have a question about a wing model... The model I have is an airplane wing (airfoil) in a wind tunnel. The wing is supported at the quarter-chord length and the wing body is free to move. My model is in the time domain with an oscillatory force at 20 Hz applied to the wing...

So heat is vibration of atoms in lattice (or fluid). Heat is also electromagnetic radiation. Do we say "heat is electromagnetic radiation", or is that incorrect, since heat is vibration of atoms in lattice? Should we say "heat is __spread by__ electromagnetic radiation instead?

Frequency of vibration for non-uniform membrane -- Partial Differential Equations Hi guys, I'm having a lot of trouble with a conceptual problem in my PDE's homework. I don't think the answer involves a lot of work, I think I'm just not understanding something... Homework Statement Consider...

Hi guys, I want to estimate vehicle pitching, bouncing and rolling natual frequencies. I am doubdful in the vehicle excitement. How can I understand if the excitation has a good frequency content?

Homework Statement A body of arbitrary shape has a mass m, mass center at G with a distance of D and a radius of gyration about G of K. It is hanging, and pinned at the top. If it is displaced a slight amount of angle P from it's equilibrium position and released, determine the natural period...

Hi all, I am confused with the amplitude at 1x, 2x, 3x frequency. The 1x, 2x and 3x is the harmonic (or mutiples) of the original frequency, meaning that if the shaft is turning at 1500rpm, then 2x will be the amplitude at 3000rpm and 3x will be the amplitude at 4500rpm right? But how will...

Homework Statement the problem is in the attached file, I am having trouble with part d and e. cheers. [the answer for B is mr^2(0.5-16/9pi^2)] Homework Equations The Attempt at a Solution i won't upload all my working as i have stuff everywhere but for part d: i got my...

Im new here and I am not an engineer but i have a question hopefully someone can offer their thoughts on.. I film and record bands live and i want to run a video camera at concerts that are often very loud.. At times I also need to position the camera in front of the PA speakers and this...

Hi looking for some help on the below I'm a little bit stuck. The effect of an earthquake on an elevated water tank is to be investigated. The water tank has mass m=2x10^6 kg and natural frequency wn=10.6 rad/s and a damping coefficient of 12% critical damping. Ground acceleration can be...

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

Homework Statement If the generalized driving forces Qi are not sinusoidal, and the dissipation function is simultaneously diagonalized along with T and V, show that the forced vibrations are given by \zeta_i = \frac{1}{2\pi}\int_{-\infty}^\infty \frac{G_i(\omega) (\omega_i^2 - \omega^2 + i...

Homework Statement I am trying to solve how to select a vibration isolator for a machine to be mounted on a vibrating surface. I know the disturbance frequency, 22.5Hz and the mass of the machine is 40kg. I have selected some commercially available rubber isolators and subsequently know their...

Homework Statement I'm using Eugene Hecht's 4th edition of Optics, doing problems from chapter 8 on polarization. Write an expression for a polarization-state lightwave of angular frequency (omega) and amplitude E propagating along the x-axis with its plane of vibration at an angle of 25...

Homework Statement I've been given this as a piece of coursework and I'm having a bit of trouble starting it. I know most of what I need to do once I can figure out how to calculate a few basic (though essential) values. The first part to the question is as follows: "Determine, using matrix...

Hello, I am new in computational chemistry. I was calculating by "Moller Plesset Second Order perturbation theory -MP2-" (using GAMESS) molecular parameters of Cs3Cl2-. Among them i found two complex frequencies of vibration. My question is now, what is the physical meaning of those complex...

say a system has 3 modes. under free vibration does it vibrate in all the modes all just one mode? why. also if we apply a either a impulse or pulsating force to the system, in which modes the system is going to vibrate and why? thanks.

I want to calculate or model the vibration phenomena of tubes (specifically carbon tubes, gun barrels etc): such factors as time before coming to rest, vibration cycle(s), frequency etc that different designs of tubes exhibit when subjected to a force. One question in particular I would like to...

[b]1. Frame made up of 3 rigid bars linked to each other and the ground by rotational springs, k, a viscous damper, c which connects opposite corners of the frame. Subject to base lateral motion (s(t)), and the two vertical bars rotate by an amount theta(t). Assuming small displacements...

Hi! I am new. Please call me Kaffe. I am a theologian of the Extraterrestrial Presence and my studies have led me to Physics and the Science of Frequency and Vibration. I have been thinking about developing a project over the summer to see if I can get an object to hover using intense shock...

I'm wondering about what's going on in an effect I've noticed with heating pads (as well as electric mattress pads). Try this experiment: take an ordinary heating pad (one of those flat rectangular things about 1 foot by 1.3 feet with an electric plug), plug it in, and have a friend sit...

hi guyz, I have Turbiine(5500RPM)-Gearbox(output 1500RM)-Generator-Exciter-Permanent Magnetiic Generator(PMG). I have problem with high axial vibration at ball bearing permanent magnetic generator. Axial vibration at 5500RPM, but it rotate at 1500RPM. This overall is 3-5 times radial...