Damped Definition and 383 Threads

Damping is an influence within or upon an oscillatory system that has the effect of reducing or preventing its oscillation. In physical systems, damping is produced by processes that dissipate the energy stored in the oscillation. Examples include viscous drag (a liquid's viscosity can hinder an oscillatory system, causing it to slow down) in mechanical systems, resistance in electronic oscillators, and absorption and scattering of light in optical oscillators. Damping not based on energy loss can be important in other oscillating systems such as those that occur in biological systems and bikes (ex. Suspension (mechanics)). Not to be confused with friction, which is a dissipative force acting on a system. Friction can cause or be a factor of damping.
The damping ratio is a dimensionless measure describing how oscillations in a system decay after a disturbance. Many systems exhibit oscillatory behavior when they are disturbed from their position of static equilibrium. A mass suspended from a spring, for example, might, if pulled and released, bounce up and down. On each bounce, the system tends to return to its equilibrium position, but overshoots it. Sometimes losses (e.g. frictional) damp the system and can cause the oscillations to gradually decay in amplitude towards zero or attenuate. The damping ratio is a measure describing how rapidly the oscillations decay from one bounce to the next.
The damping ratio is a system parameter, denoted by ζ (zeta), that can vary from undamped (ζ = 0), underdamped (ζ < 1) through critically damped (ζ = 1) to overdamped (ζ > 1).
The behaviour of oscillating systems is often of interest in a diverse range of disciplines that include control engineering, chemical engineering, mechanical engineering, structural engineering, and electrical engineering. The physical quantity that is oscillating varies greatly, and could be the swaying of a tall building in the wind, or the speed of an electric motor, but a normalised, or non-dimensionalised approach can be convenient in describing common aspects of behavior.

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  1. I

    Create a graph of the position of a damped oscillator as a function of time.

    This is an assignment for a class titled "Intro to Scientific Programming" and it is a prerequisite for Computational Physics. Homework Statement Create a graph of the position of a damped oscillator as a function of time.Homework Equations The equation is x = A*e^((-b/2m)*t)cos(omega*t +...
  2. M

    Use Fourier transform to solve PDE damped wave equation

    This question is also posted at http://www.mathhelpforum.com/math-help/f59/use-fourier-transform-solve-pde-damped-wave-equation-188173.html Use Fourier transforms to solve the PDE \displaystyle \frac{\partial^2 \phi}{\partial t^2} + \beta \frac{\partial \phi}{\partial t} = c^2...
  3. S

    Green's function for a critically damped oscillator

    Homework Statement Consider critically damped harmonic oscillator, driven by a force F(t) Find the green's function G(t,t') such that x(t) = ∫ dt' G(t,t')F(t') from 0 to T solves the equation of motion with x(0) =0 and x(T) =0Homework Equations x(t) = ∫ dt' G(t,t')F(t') from 0 to TThe Attempt...
  4. K

    Damped harmonic oscillator of spring

    Homework Statement A spring is elastically stretched 10 cm if a force of 3 Newtons is imposed. A 2 kg mass is hung from the spring and is also attached to a viscous damper that exerts a restraining force of 3 Newtons when the velocity of the mass is 5 m/sec. An external force time function...
  5. A

    Question about Damped Simple Harmonic Oscillation ?

    Question about Damped Simple Harmonic Oscillation !? Under appreciable damping , Why amplitude resonance and Velocity resonance occurs at slightly different frequencies ? - Abir Sarkar
  6. E

    Critically damped current in this network

    Homework Statement I'm supposed to find whether the current in the following network is a) under-damped b) critically damped c) undamped c) over-damped Homework Equations According to Kirchoff's laws The Attempt at a Solution The answer given by my professor for this...
  7. K

    What are the conditions for different types of damping in oscillations?

    Homework Statement A mass m moves in one dimension x subject to a restoring force −kx and a damping force −γ[(x)\dot]. What are the conditions for underdamped oscillations, overdamped oscillations, and critical damping? Now, suppose m is 0.80 kg, γ is 1.18 kg/s, and the oscillations are...
  8. K

    How Does a Critically Damped Oscillator Behave After a Sharp Impulse?

    Homework Statement If the damping constant of a free oscillator is given by b=2 m ω0, the oscillator is said to be critically damped. Show by direct substitution that in this case the motion is given by x=(A+Bt)e^(−βt) where A and B are constants. A critically damped oscillator is at...
  9. K

    How to Solve for x(t)/x0 in a Damped Oscillator with Initial Values?

    Homework Statement The equation for a damped oscillator is d2x/dt2+2βdx/dt +ω02 x = 0. Let ω0=1.0 s−1 and β = 0.54 s−1. The initial values are x(0) = x0 and v(0)=0. Determine x(t)/x0 at t = 2π/ω0. Homework Equations the solution to equation is given by...
  10. K

    Logarithmic decrement of a lightly damped oscillator

    Homework Statement The logarithmic decrement δ of a lightly damped oscillator is defined to be the natural logarithm of the ratio of successive maximum displacements (in the same direction) of a free damped oscillator. That is, δ = ln(An/An+1) where An is the maximum displacement of the n-th...
  11. K

    A lightly damped harmonic oscillator

    Homework Statement The logarithmic decrement δ of a lightly damped oscillator is defined to be the natural logarithm of the ratio of successive maximum displacements (in the same direction) of a free damped oscillator. That is, δ = ln(An/An+1) where An is the maximum displacement of the n-th...
  12. T

    Damped harmonic oscillator being forced

    Homework Statement A damped harmonic oscillator is being forced. I have to say whether it is direct forcing or forcing by displacement. I have the equation of motion which is expressed in terms of the particle's height above the equilibrium point and an expression for the force being...
  13. T

    How Does Damping Affect Oscillation Amplitude and Frequency?

    Homework Statement The drawing to the left shows a mass m= 1.8 kg hanging from a spring with spring constant k = 7 N/m. The mass is also attached to a paddle which is emersed in a tank of water with a total depth of 27 cm. When the mass oscillates, the paddle acts as a damping force given by...
  14. F

    Forced vibrations of damped single degree freedom systems?

    in a spring mass damper system subjected to a periodic force. the response of the system only depends on the force and the restoring forces caused due to the spring is ignored because the damper is assumed to have taken care of it. now it's here that my confusion originates. in a damped free...
  15. Q

    Function for (damped) SHM as a linear combination of two exponentials

    So, in lectures we derived the equation for damped SHM by solving the differential equation relating position (x), mass (m), spring constant (s), and damping coefficient (r): m\ddot{x}=-\frac{s}{m}x-r\dot{x} Using a solution of the form Ae^{\alpha t}, we find that: x=Ae^{-pt}e^{\pm qt}...
  16. L

    Deriving the damped circuit equation and energy dissipated through a resistor.

    Homework Statement I figure I will just combine these two questions into one topic. 1) The energy stored in a capacitor is .5CE^2, where E is the voltage. Wat is the instantaneous power dissipated in a resistor R through which this capacitor discharges? Show that the total energy dissipated...
  17. D

    Damped Harmonic Oscillator Using Greens Theorem

    Hi there, I just started an intermediate classical mechanics course at university and was smacked upside the head with this question that I don't know how to even start. Homework Statement We are to find the response function of a damped harmonic oscillator given a Forcing function. The...
  18. K

    Simple Damped Harmonic Oscillator with friction

    Homework Statement a block of mass m=.5kg is sliding on a horizontal table with coefficients of static and kinetic friction of .8 and .5 respectively. It is attached to a wall with a spring of unstretched length l=.13m and force constant 200 n/m. The block is released from rest at t=0 when...
  19. K

    Damped harmonic oscillator with a CONSTANT frictional force

    Homework Statement There is a block attached to the wall via a spring. The only damping force is friction, where there is kinetic and static. Homework Equations m(d^2x/dt^2)=-kx-? The Attempt at a Solution I can solve this, except usually the damping force is given as...
  20. S

    Building Software for Damped Pendulum in Electric Field

    Firstly, I spoke to a Physics teacher and some strangers on the internet as well as Googled and this is the situation I am in now. I want to build a software simulation for school of a damped-oscillation non-zero charged metallic-sphere pendulum within the uniform electric field of a...
  21. C

    Damped Harmonic Oscillation Problem

    Homework Statement A 100g mass is suspended on a rubber band with a k coefficient of 2.74 N/m. The original amplitude of the oscillations is 5cm and after 100 oscillations, the maximum speed of the weight is 0.13 m/s. Find the damping coefficient y. Homework Equations d2x/dt2 + γdx/dt...
  22. X

    How Do Initial Conditions Affect Solutions in Damped SHM with Forced Motion?

    Homework Statement [PLAIN]http://img848.imageshack.us/img848/1150/damped.png Homework Equations The Attempt at a Solution Part i) x(t) = C1coswt + C2sinwt dx/dt = -C1wsinwt +C2wcoswt using IC's: xo = C1 dxo/dt = C2w therefore x(t) = xocoswt + (dxo/dt)/w sinwt but...
  23. F

    How do I find the other particular solution?

    Homework Statement A Force F(t) = F0(1 - e-at), where both F0 and a are constants, acts over a damped oscillator. In t = 0, the oscillator is in it's equilibrium position. The mass of the oscillator is m, the spring constant is k = 2ma2 and the damping constant is b = 2ma. Find x(t)...
  24. M

    Why Do Different Software Show Varied Results for 3D Damped Spring Plots?

    Hi I tried 3Dplot Damped spring(steel spring,oil damper) in two sotwares ,and get odds results . Which one is right? In "Maxima gnuplot engine" In "WolphramAlpha engine"
  25. JJBladester

    Damped oscillations in a vacuum chamber

    Homework Statement A 200 g oscillator in a vacuum chamber has a frequency of 2.0 Hz. When air is admitted, the oscillation decreases to 60% of its initial amplitude in 50 s. How many oscillations will have been completed when the amplitude is 30% of its initial value? Homework...
  26. A

    Does Damping Affect the Period of SHM?

    Homework Statement I've been given (or have calculated) the equation for damped SHM of a spring, and have been told to calculate the period... I'm given that: Forced produced by damper: b(dx/dt) where b = 16N/ms k = 344.5N/m m = 2kg Homework Equations I know that T = 2*pi/(W0)...
  27. T

    Critically damped oscillator: Classical mechanics help

    Homework Statement A critically damped oscillator with natural frequency \omega starts out at position x_0>0. What is the maximum initial speed (directed towards the origin) it can have and not cross the origin? Homework Equations For the case of critical damping...
  28. R

    Damped Harmonic Motion with a Sinusoidal Driving Force

    1. An oscillator with mass 0.5 kg, stiffness 100 N/m, and mechanical resistance 1.4 kg/s is driven by a sinusoidal force of amplitude 2 N. Plot the speed amplitude and the phase angle between the force and speed as a function of the driving frequency and find the frequencies for which the phase...
  29. F

    Damped Oscillations. Mass Hanging from a spring

    Damping is negligible for a 0.121 kg mass hanging from a light 6.55 N/m spring. The system is driven by a force oscillating with an amplitude of 1.45 N. At what frequency will the force make the mass vibrate with an amplitude of 0.465 m? There are two possible solutions, enter one of them...
  30. S

    MDOFs damped system: transfer function estimantion

    I need to calculate the transfer function of a 4 DOFs system, in particular I need to calculate the system natural frequencies. Do you know to figure out these? On books I have found how to get it in the undamped case. Thanks
  31. Y

    Mean power in driven, damped harmonic oscillators

    Ok, there's a bit I don't understand in my lecture notes. The maths doesn't seem to quite work out. Any help would be appreciated. Here's the section I'm confused about: http://img228.imageshack.us/i/physy.jpg/ It's the transition from the second last line of working to the last line which I...
  32. D

    Plot envelope of damped vibration.

    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) *...
  33. C

    Lightly damped oscillator, what is the time constant

    Homework Statement I need to find the time constant, tau, Homework Equations WILL EDIT THIS TOMORROW Bleeping FMS giving me major brainache *saddest face ever* A(t) = A_0 times e^-t/tauThe Attempt at a Solution I have had numerous attempts and I just fried my (fibromyalgic) brain out with...
  34. M

    Damped Harmonic Motion Time Constant?

    Homework Statement A spring with spring constant 17.0 N/m hangs from the ceiling. A 530 g ball is attached to the spring and allowed to come to rest. It is then pulled down 7.00 cm and released. What is the time constant if the ball's amplitude has decreased to 3.50 cm after 41.0...
  35. A

    Newton-Raphson solution for damped oscillation

    1. The oscillation amplitude of a damped system is given by: x=-8e^0.5θ sin3θ Where θ is in radians Using the Newton-Raphson iteration method, determine the value of t, near to 5.2 correct to 4 significant figures, when the amplitude is zero. 2. Newton's equation r_2=r_1-f(r_1...
  36. I

    How Does Archimedes' Principle Affect Damping in Harmonic Oscillations?

    Hi, I'm trying to build up a mass spring system, which is damp by a small steelball lowered into a buck containing soap mixture. Where the viscosity has been measured and we have calculated the flow arround the ball to be rather laminar (Reynold<1). But our data shows a damping around the double...
  37. S

    Damped Coupled Oscillators, Deformations and Energy Lost in Collisions

    I'm doing a research project on collisions and I've come across a part of my theory that requires solutions to coupled damped oscillators. Could anyone please refer me to some text on 2 coupled damped oscillators which isn't extremely math heavy and has conceptual explanations of the...
  38. L

    Resonant behaviour of damped beam

    hi all i have a problem in finding the quality factor of cantilever beam (one end is fixed and other end is free ) vibrating in air /other medium? how the qualtiy factor expression for beam is calculated? whether all these expressions applicable to micro and nano cantilevers. please explain...
  39. L

    Resonant behaviour of damped beam

    hi all i have a problem in finding the quality factor of cantilever beam (one end is fixed and other end is free ) vibrating in air /other medium? how the qualtiy factor expression for beam is calculated? whether all these expressions applicable to micro and nano cantilevers. please explain...
  40. W

    Damped Oscillation: Finding Time Constant

    Homework Statement The amplitude of an oscillator decreases to 36.8% of its initial value in 10.0 s. What is the value of the time constant? Homework Equations xmax=Ae^-bt/2m Time constant= m/b xmax(t)= Ae^-t/2(timeconstant) The Attempt at a Solution I'm not quite sure where to...
  41. I

    Nondimensionlize damped spring

    Homework Statement Vertically suspended spring with mass attached. F = ma gives the diff eq: m(d^2y/dt^2) + b(dy/dt) + ky = 0. y(t) measures the vertical position (upward is positive) of the mass relative to the equilibrium position (how far the mass hangs down if it is not moving). m =...
  42. G

    Mathematica How do I fit damped harmonic motion data (x vs. t) using Mathematica?

    How do I fit the data given below into the standard form (ignore the part saying to use MathCad): http://screensnapr.com/u/apmqkd.png {{{0.002, 0.726}, {0.022, 0.739}, {0.042, 0.75}, {0.062, 0.759}, {0.082, 0.768}, {0.102, 0.776}, {0.121, 0.785}, {0.141, 0.794}, {0.161, 0.802}...
  43. J

    Mircocanonical Damped Harmonic Oscillator

    I am supposed to find the number of mircostates for the following Hamiltonian \ \begin{equation} \Sigma {(q_n+mwp_n)^2}<2mE \end{equation} So I am attempting to take the integral as follows \ \int e^{(q_n+mwp_n)^2} d^{3n}q d^{3n} p [tex\] I found a solution that tells me \...
  44. S

    How Does Damping Affect the Resonant Amplitude of a Driven Pendulum?

    Homework Statement Given a simple pendulum with a mass on the end and a massless string. The support point for the pendulum is moved laterally with an amplitude D at the resonant frequency. The damping is from the air and is considered viscous i.e. not turbulent. The difference between the...
  45. B

    How Do You Solve a Damped Oscillator Problem with Initial Conditions?

    Hi, I have a question about damped oscillator. Actually, although I have read courses about oscillator, I couldn't solve this. I think this is very easy question :( 1. Homework Statement Consider the solution for the damped ( but not driven ) oscillator, x =...
  46. D

    Lightly Damped Simple Harmonic Oscillator

    Tuning forks are lightly damped SHO's. Consider a tuning fork who's natural frequency is f=392Hz. Angular frequency = w = 2(Pi)f = 2463 (rad/s) The damping of this tuning fork is such that, after 10 sec, it's amplitude is 10% of it's original amplitude. Here is my attempt to find the damping...
  47. A

    How Does Damped Oscillation Apply to a Spring-Mass System on a Smooth Surface?

    Homework Statement Help need with this problem. A light spring AB of natural length 2a and of modulus of elasticity 2amn2 lies straight at its length and at rest on a smooth horizontal table. The end A is fixed to the table and a particle P of mass m is attached to the midpoint of the spring...
  48. D

    Is the D.E. Solution Affected by the Presence of a Non-Homogeneous Term?

    Homework Statement Let ay'' + by' +cy = R(x) Determining whether a system is under/over/critically damped depends on the size of b^2 compared to 4ac. Does it depend at all on R(x)? Homework Equations Characteristic equation, quadratic equation. The Attempt at a Solution...
  49. T

    Free damped pendulum solution : closed form

    I am modelling a free damped simple pendulum and was wondering if anyone could refer me to a paper or perhaps provide me with an expression describing the motion of the pendlum with large initial amplitude. I have solved the equations numerically but am implementing an optimization routine and...
  50. P

    Damped Harmonic Motion Equation

    I am having trouble finding out what the equation for damped harmonic motion is. I have been researching around there there are many small variations on the exponents. I am conducting an experiment which has involved the use of the spring constant from Hooke's Law and have used a hypothesis...
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