Vehicle Ride

1. Usually when wheel goes over bump for perticular wheel travel spring does not deflect same as much of wheel hence usually difference in wheel rate and spring rate
2. Ride rate corresponds to displacement of vehicle body w.r.t to ground and wheel rate corresponds to dispacement of vehicpe body w.r.t to wheel center hence there is difference.Hence, when calculating ride rate we need to consider tyre stiffness.
3. i. Same amount of damping can not be used in case of low frequency and high frequency region as transmissibility depends upon low and high damping values. Hence if damping is low in high frequency region ride will be good but in low frequencyvregion ride will be harsh similarly in case of high damping low frequency ride will be better than high frequency region ii. In case if rebound and compression also damping can not be same as if damping is higher in case compression suspension would not work properly as total stiffness will increase in case of compression and to release aborbed enegry is rebound conditio damping must be higher other wose it will take more time for system to release abrobed energy and settle down.
4. Due to Out of phase motion and time lag between front and rear pitching occurs in car. Hence to reduce pitching rear suspension needs to come in phase with front suspension as soon as possible hence, it should have higher ride frequency
5. To improve suspension isolation in wheel hop one should have lower unsprung mass and lower damping. With lower damping transmissibility in higher frequency region is lower hence less excitations are transferred to sprung mass which results in better ride and improved suspension isolation.
6. Ride frequency in air suspension remains fairly constant in unladen and laden condition hence results in similar ride quality in unladen and laden condition. Hence preffered in heavy vehicles
7. Sprung mass natual freq. 1.18 Hz & unsprung mass natursl freq. 11.8 Hz

8.1 time lag 0.416 sec

8.2 time lag 0.143 sec

Time lag due 92.47 inch wheelbase at given speed is nearly 0.135 sec

Hence, option 2 ride frequency set will work better in this case for flat ride