Effect of Damping

Every phenomenon observed in nature has always been driven by some kind of stimulus. From a traversing vehicle to planetary motions and rotations, every observable motion is directly or indirectly related to the application of force. Had there been no applying force, there would be no possibility to do any kind of work. But force is not at work just to bring about motion; it also stops motion.

What are damping forces?

Damping forces are a particular type of force used to slow down or stop a motion. The key point is that damping forces only work on vibratory motion or systems that exhibit an oscillatory nature. It is a force that restricts vibrations that can be mechanical or electrical in nature. The damping effect caused by damping forces is due to the dissipation of energy.

The aim of any damping force in an oscillatory system is to decrease the amplitude of its oscillation or prevent the oscillation from happening. Damping is an effect that is caused by damping forces and occurs in almost every system. For damping to not occur in a system, it has to be free of any forces that oppose the oscillatory motion of the force. Every force that is applied receives a response, and this response acts as the damping force.

What are the effects of damping?

Damping forces are responsible for slowing down the oscillatory motion of an oscillating body, but what exact effect do damping forces have? Let us have a look.

Decrease in amplitude due to damping forces

This is the most obvious effect of any damping force. Amplitude gives the extent to which an oscillatory motion occurs. The amplitude of an oscillatory system gives the energy stored in the oscillatory system. Therefore when a damping force affects an oscillatory system, it causes the energy of the system to decrease and consequently affects the amplitude of the oscillation to decrease. The decrease in amplitude can be gradual or very sharp depending on the level of damping force that is applied to the system. In an ideal system, the amplitude of the oscillatory system remains unchanged, but this cannot be recreated in the physical world.

Change in angular velocity due to damping forces

The energy in an oscillator is also seen in the angular velocity of the oscillating body. This means if the energy of the system changes, the angular velocity with which the oscillations happen will also change. This is further consolidated by the fact that with an increase in the damping force applied to the system, the total energy of the oscillating system gets dissipated, which causes the system’s angular velocity to change.

Types of damping forces

Different types of damping forces can occur in a system; the most observed ones are listed below.

Mechanical Damping Forces

This is an instance where the use of mechanical forces has damped the oscillations of a body. These damping forces are called mechanical damping forces, and these damping effects are called mechanical damping. The maximum observable mechanical damping force is friction. It usually involves the conversion of the mechanical motion of an oscillating body into heat and then dissipating, hence decreasing the body’s kinetic energy.

Viscous Damping Forces

In most oscillating systems, such as spring loads and tires, the damping effect is applied with the requirement of a very viscous fluid. In a viscous fluid, the viscous drag is observed, which is the same as friction. Whenever an oscillating body is subjected to viscous drag, the kinetic energy of that particular body is dissipated at a much faster rate than if the same oscillating body was placed in air. Viscous drag most of the time causes the system to be overdamped, which leads to the oscillations quickly dying to zero.

Electrical Damping Forces

In an alternating current system, the oscillations happen with respect to the polarity of the current being passed. These oscillations of the current are opposed by the damping force provided by resistors. They dissipate the energy carried by the electric current in the form of heat, thus reducing the actual energy received by the receiver.

Electromagnetic Damping Forces

Radiation damping is observed due to electromagnetic damping forces and is usually observed in subatomic particles. For example, when an electron is excited, it starts oscillating; when this oscillation starts, the mechanical energy of the electron is dissipated in the form of electromagnetic waves.

Conclusion 

Damping forces are forces that are applied to slow down motion. A damping force is existent in almost every system that exists in nature. Understanding the effect of damping forces is vital in understanding the motion of entities and predicting the longevity of an experiment, or in other words, how long it will continue without external support.

The amplitude of an oscillatory system gives the energy stored in the oscillatory system. Therefore when a damping force affects an oscillatory system, it causes the energy of the system to decrease and consequently decreases the amplitude of the oscillation. It is also observed that with an increase in the damping force applied to the system, the total energy of the oscillating system gets dissipated, which causes the angular velocity of the system to change.