Problem set 3 -week 3 challenge
1.
(i) Roll moment (ft-lb/g) = 7643.554421
(ii) Roll gradient (deg/g) = 3.184814
(iii) Load transfer due to roll or elastic component (lb/g) = 1563.63199
(iv) Front roll stiffness (ft-lb/deg) at wheel center level = 1989.334195
(v) Front anti-roll spring rate (lb/in) for one wheel jounce = 149.102724
(vi) Front anti-roll spring rate (lb/in) for roll = 298.20544
( vii) Front anti-roll bar stiffness (ft-lb/deg) = 1491.6797
(viii) Auxiliary roll stiffness (%) = 70.986525
Procedure : -
1. The given values were checked and converted to one unit .
2.Using the ride rate and tire stiffness , the front the wheel rate was calculated .
3.The roll gradient was the first thing to be calculated .
4.The lateral and gravity conponent was then calculated.
5.The roll moment was caculated using the ading the lateral and gravity component .
6.load transfer due to elastic componet was calculated .
7.The tire contribution to roll stiffness value was caculated .
8.The total front roll stiffness at wheel centre level was calculated .
9.The front wheel rate contribution was determined .
10. This value was subtracted from the total roll stiffness to calculate the roll stiffness without tire rate in it.
11.Using the above value the auxillary rate % was caculated .
12 Now the anti roll bar rate for one wheel jounce value is caculated .
13. To calculate the anti roll spring rate for roll the above value is multiplied by 2 .
14. The final anti roll bar stiffness is caculated in pounds-inch/deg unit .