Free vibration is a common physical phenomenon with many applications in engineering and science. It is the study of systems that vibrate at their natural frequency in response to a disturbance or excitation. This article will discuss the definition and basics of free vibration, the various types of free vibration, and the various applications of free vibration.
Free Vibration is a type of mechanical vibration in which the object oscillates around its equilibrium position without any outside influences. It occurs when an object or system is disturbed and then left to vibrate naturally, with no external forces. In free vibration, the system vibrates at its natural frequency, which is determined by its mass, stiffness, damping and shape. Most objects, such as springs and pendulums, can vibrate naturally without any input from an external source.
Various types of energy such as kinetic energy, potential energy, and strain energy exist within a vibrating object. The total energy in the system is constant, with some energy being transferred back and forth between the potential and kinetic components. If there are no dissipative forces, the free vibration cycle will continue indefinitely. However, in most cases, friction and other damping forces will decrease the amplitude of the vibration over time.
Free Vibration is also known as natural vibration, and can be divided into two categories: undamped vibration, where there is no dissipation of energy, and damped vibration, where energy is dissipated over time. In both cases, the motion is described by the equation of motion, which includes the mass, stiffness, damping, and external forces acting on the system. Furthermore, the frequency spectrum of the system is used to determine the various frequencies of vibration and their corresponding amplitudes.
Free Vibration can be divided into two types: forced and natural. Forced vibration is caused by an external source such as a wind gust or a hammer strike. Natural vibration occurs without any input from outside sources and is simply the result of the material’s natural elasticity.
The two types of forced vibration are steady state vibration and transient vibration. Steady state vibration means that the external force continues to act for a long period of time, resulting in a constant amplitude vibration. Transient vibration is short-lived and depends on the type of external force applied.
In natural vibration, the system has no external forces acting on it, so only its own elasticity causes it to oscillate. There are two types of natural vibration: harmonic and non-harmonic. Harmonic vibration is usually regular and periodic, while non-harmonic vibration is usually chaotic and unpredictable.
Both types of free vibration are important to understand because they can have significant effects on equipment, structures, and design. For example, if the natural frequency of a machine part is too close to that of an external force, then it could amplify the vibration and damage the machine part. On the other hand, if the natural frequency of a machine part is too low, it can cause fatigue and lead to failure. It is therefore essential to know the various types of free vibration and their effects.
Free Vibration has many practical applications in various areas of engineering. For example, it can be used to measure the stiffness of a material or structure by subjecting it to vibration and then analyzing the response. This technique is useful in civil engineering where structures such as bridges and buildings need to be designed to withstand certain levels of movement and vibration. It is also used in mechanical engineering to determine the natural frequencies of a system, which can then be used to calculate the resonance frequency and therefore optimize the system for better performance.
In addition, free vibration can be used to identify defects and damage in a material or structure. By introducing an external force, the natural frequencies can be determined and compared to what is expected from an undamaged structure. Any differences can indicate the presence of damage or wear. This kind of analysis can be used in the fields of aerospace, automotive and industrial engineering.
Finally, free vibration can also be used to protect against seismic activity. By analyzing the natural frequencies of a building or structure, engineers can design a system that is tuned to the most common earthquake frequencies. This will help dissipate energy and reduce the level of shaking experienced by the occupants during an earthquake.