Purpose To Evaluate the Vibration Isolation performance of the suspension that our team designed
Procedure Developed a base excitation Single-Degree-of- Freedom model for the RC car front suspension mounted on road test simulator
Transmissibility curves for a base excited system
It was decided that we would like to have a frequency ratio of around 2 for our design
With the general value of the frequency ratio determined, our spring constant (k) could be calculated This spring constant would have to be calculated using both the 4Hz situation and the 10Hz
With the spring constant calculated it was time to calculate the damping constant The damping constant can be found by having a known damping ratio (zeta) We decided that our RC car suspension should proved an overall smooth ride so a damping ratio of 0.5 was considered
With the damping constant determined we could then choose the closest available set of spring and damper Our analytical results for the damper and spring were 23.6 and 703 respectively The Blue Damper was chosen with a value of 23.2 Ns/m The Red Spring was chosen with a value of 703.1 N/m Our analytical model of our selected damper/spring assembly could now be plotted and compared to experimental data that was collected
Comparison of Analytical & Experimental @ 4Hz Our analytical response transmitted less g forces than the experimental results displayed. This could be due to the uncertainty in the spring and damper constants.
Comparison of Analytical & Experimental @ 10Hz The phase does not line up between our analytical and experimental data but this is because we did not take phase into consideration in this experiment. Like the 4Hz case the experimental data displays higher G forces then the analytical model.