Development of a Multi Degree-of-Freedom Vibration Exciter for Laboratory Applications

Introduction of vibration to manufacturing operations such as casting and welding has proved to improve the physical and mechanical properties of manufactured parts. A vibration exciter is developed for the purpose of generating and inducing vibration, along different degrees of freedom, on objects placed on its surface. The equipment applies an eccentric mass drive system which gives the equipment an overall advantage in varying the vibration parameters. The acceleration of the vibratory motion of the equipment was measured using an accelerometer and oscilloscope set-up. The natural frequencies of the different vibration modes are also obtained from a developed mathematical model executed using the MATLAB Simulink software. The developed equipment successfully generated random sinusoidal vibrations of accelerations ranging from −5 m/s^2 to 8 m/s^2 along the principal axes and angular accelerations ranging from −40 rad/s to 40 rad/s about the pitch and roll axes. Natural frequencies of f_x = 3.78 Hz, f_θ = 7.94 Hz and f_φ = 9.89 Hz are obtained along the vertical, pitch and roll directions respectively. The presented results indicate that the developed machine successfully satisfied the proposed hypothesis of being able to measure vibrational characteristics along different degrees of freedom.