Ride Frequency Calculation and Graphing - Problem Set 2 Week 2 Challenge

Understood the concept of the flat ride and completed the derivation and graphs for the various loading conditions.

Found out the required parameters using excel.

Question Requirments:

1. Recommended rear sprung mass frequency based on speed and wheelbase at the half-load condition.

Ans: The rear frequency must be 20% greater than front frequency to avoid pitching motion which is uncomfortable to the passengers. Thus the recommended rear frequency is

1.15 + (0.2*1.15) = 1.38 Hz

2. Front sprung mass natural frequency at half load.

Ans: 1.15 Hz

3. Front spring rate.

Ans: 260388.989 N/m

4. Rear spring rate.

Ans: 339100.346 N/m

5. Front sprung mass natural frequencies at curb and GVW.

Ans: 2.85502 Hz and 2.636269842 Hz

6. Rear sprung mass natural frequencies at curb and GVW.

Ans: 3.99031879 Hz and 3.090887641 Hz

7. Front unsprung mass natural frequency at all three load conditions.

Ans: Curb - 8.3081082 Hz

Half-Load - 8.3081082 Hz

GVW - 8.308108197 - Hz

8. The rear unsprung mass natural frequency at all three load conditions.

Ans: Curb - 10.1753129 Hz

Half-Load - 10.1753129 Hz

GVW - 10.1753129 - Hz

9. Rear/Front frequency ratio for all three load conditions

Ans: Curb - 1.39765003

half-load - 1.288935296

GVW - 1.172447369

Bump Oscillation Profile:

Curb Weight plot:

Half-load plot:

GVM plot:

Calculated Excel file:

https://drive.google.com/file/d/1mBvVnjboncfrDva8ovRlefvIQPuHQyki/view?usp=sharing