I think there may be a bit of a terminology confusion here. The displacement is a periodic function in vibration. The amplitude is the maximum displacement, so it is not periodic.roshan2004 said:In forced vibration, amplitude of vibration changes periodically. Is it right ? I think it is a correct statement, since the amplitude of vibration is a periodic function.
Forced vibration is a type of vibration that occurs when a system is subjected to an external force or input. This force can be periodic, such as a regular oscillation, or non-periodic, such as a random or impulsive force.
Natural vibration occurs when a system is disturbed from its equilibrium position and vibrates at its natural frequency. Forced vibration, on the other hand, is caused by an external force acting on the system, which may not necessarily be at the system's natural frequency.
The amplitude of forced vibration is affected by several factors, including the magnitude and frequency of the external force, the stiffness and damping of the system, and the system's natural frequency. Additionally, the location of the force application and any resonance effects can also impact the amplitude of forced vibration.
The amplitude of forced vibration can change periodically due to the frequency of the external force. This is known as amplitude modulation, where the amplitude of vibration increases and decreases periodically in response to the varying frequency of the external force.
Forced vibration is commonly seen in engineering and structural systems, such as bridges, buildings, and aircraft, where external forces can cause vibrations. It is also used in musical instruments, such as guitars and violins, where the strings are plucked or strummed to create forced vibrations at specific frequencies.