International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 1449 FREE VIBRATION ANALYSIS ON CANTILEVER BEAM- A REVIEW Simarnjit Singh 1 , Amandeep Singh 2 , 1 Department of Mechanical Engineering, CTIEMT Jalandhar. 2 Assistant Professor, Department of Mechanical Engineering, CTIEMT Jalandhar. ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - A simple and unified approach is presented for the vibration analysis of a cantilever beam. Natural frequency and damping ratio are calculated with an experimental process. Estimating damping still remains as one of the biggest challenge in structure made of different materials like brass, stainless steel and aluminium. All materials or structures posses certain amount of internal damping, due to which energy is either dissipated into heat or radiated away from the system. Internal damping includes the 10-15% of the total damping in system. The primary objective of this thesis is the free vibration analysis of different materials under surface cracks to estimate the effect of cracks on damping ratio and natural frequency. All the values will find with the help of Vibscanner and Omnitrend software under a free vibration test. Key Words: Cantilever Accelerometer sensor, Cantilever Beam, Natural Frequency, Clamp, Damping ratio, Free Vibration, Vibscanner, Omnitrend. 1.INTRODUCTION Vibration is the motion of a particle or a body or system of connected bodies displaced from a position of equilibrium. Most vibrations are undesirable in machines and structures because they produce increased stresses, energy losses, cause added wear, increase bearing loads, induce fatigue, create passenger discomfort in vehicles, and absorb energy from the system[1]. Vibration can be desirable: for example, the motion of a tuning fork, the reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker[2]. Yet, most vibrations are undesirable in machines and structures since they deliver expanded burdens, vitality misfortunes, cause included wear, build bearing burdens, affect weakness, make traveler uneasiness in vehicles, and assimilate vitality from the system. Pivoting machine parts need watchful adjusting with a specific end goal to keep harm from vibrations. Vibration analysis is one of important process in the field of mechanical engineering. The effect of vibration absorber on the rotating machineries, vehicle suspension system and the dynamic behavior of machine tool structures due to excitation are the important information that design engineer wants to obtain. This information is very helpful in designing the system so that to overcome the negative effects due to excessive amplitude of vibration. A beam is a structural element that is capable of withstanding load primarily by resisting against bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment[3]. In case of cantilever beams, a horizontal cantilever beam under a vertical load will bend downward and when this force is removed, the beam will return to its original shape; but the inertia of beam tends it into motion. Thus, the beam will vibrate at its characteristic frequencies as shown in Fig -1. Fig -1: The beam under free vibration[4] The cantilever beam movement stops after some time due to the resistance offered by a body to the movement of a vibratory system. This is called as Damping. The primary objective of our work is to find out the vibration characteristics of cantilever beam under different conditions. 2.LITERATURE SURVEY A wealth of literature exists in the area of vibrations of beams but while going through the literature regarding material damping of cantilever beams it has been figured out that still a lot of work has to be done regarding it. Usually whenever study of various materials has been done the focus of researchers has been damping, mode shapes, resonant frequency, etc. but material damping has not been paid much attention. Some important literatures are given below: Shibabrat Naik, Wrik Mallik[5] estimating the dynamic properties of a cantilever by using aluminium as a cantilever. All these values are analyzed on seven different patches which are designed at constant gap on aluminium beam. Accelerometer is connected to each patch one by one and Hammer is stroked on that patch to obtain the mode shapes, modal frequencies and the damping parameters. A fast Fourier transform analyzer, PULSE lab shop was used to