Development of vibration absorber for beam structure using variable damping and stiffness

The vibration absorbers are frequently used to control and to minimize excess vibration in structural systems. To reduce the vibration of the main system or machine, the frequency of absorber should be equal to the excitation frequency. This result in subcomponent of total structure adding large input impedance to the primary structure, thus ‘absorbing’ the internal energy transferred to form primary structure. The aim of this project is to develop the variable stiffness and variable damping type vibration absorber to control the vibrations of primary system which is a cantilever beam structure using finite element method through ANSYS programming. Matlab software is used to find theoretical response of beam structure with vibration absorber. A variable stiffness vibration absorber with variable damping is developed and its stiffness can be varied by moving the support plate along the length of absorber plate and damping can be varied by adjusting distancebetween two permanent magnets. The proposed absorber was manufactured and tested on cantilever beam and it was found that absorber is very effective to control the vibration of lower as well as higher modes. The proposed absorber is suitable for vibration isolation of beam structure with uniform cross-section and facilitates vibration attenuation at variable excitation frequencies.