Week 3 - Set 3 - Anti-roll bar Optimization.xlsx

	A	B	C	D
1	Anti-roll bar optimization
2
3	Given Inputs
4
5		Parameter	Unit	Value
6		Sprung Mass	lbs	4500
7		Sprung CG Height	in	20
8		Sprung mass Roll moment Arm (h_arm)	in	19.31
9		Trackwidth	in	58.66
10		Total Front Roll Stiffness	ft-lb/deg	1300
11		Total Rear Roll Stiffness	ft-lb/deg	1100
12		Tire Stiffness	lb/in	1500
13
14		Anti Roll Bar Informations
15		Motion Ratio	in/in	0.5
16		Virtual torque Arm (A)	in	9.2
17		Center Length (B)	in	35
18		Physical Torque Arm (C)	in	11
19		Outer Diameter	mm	30
20		Inner Diameter	mm	10
21
22		Ride Rate - Front	lb/in	200
23		Ride Rate - Rear	lb/in	250
24
25	Problems
26
27	i	Roll moment (ft-lb/g)
28
29		1 in =	0.083	ft
30
31		Lateral Component =	Sprung Mass * Sprung mass Roll moment Arm
32
33		Roll moment - Lateral Component =	7241.22	ft-lb/g
34
35		Gravity Component =	Sprung Mass * Sprung mass Roll moment Arm * (π/180)
36
37		Rol moment - Gravity Component =	126.38	ft-lb/g
38
39		Total Roll Moment =	Lateral Component + Gravity Component
40
41		Total Roll Moment =	7367.60	ft-lb/g
42
43	ii	Roll Gradient (deg/g)
44
45		Roll Gradient =	Lateral Component /((Front Roll Stiffness + Rear Roll Stifness)-Gravity Componetns)
46
47		Roll Gradient =	3.18	deg /g
48
49	iii	Load Transfer due to Roll or Elastic Component (lb/g)
50
51		Load Transfer due to Elastic Component =	Total Roll moment / Trackwidth
52
53		Load Transfer due to Elastic Component =	1507.19	lb/g
54
55	iv	Front roll stiffness (ft-lb/deg) at wheel center level
56
57		Front Roll Stiffness at WC =	(Tyre Contribution * Total Front Tyre Stiffness) / (Tyre Contribution - Total Front Tyre Stiffness)
58
59		Tyre Contribution =	Tire Stiffness ( (Trackwidth2/2)(π/180))
60
61		Tyre Contribution =	3753.53	ft-lb/deg
62
63		Front Roll Stiffness at WC =	1988.80	ft-lb/deg
64
65	v	Front anti-roll spring rate (lb/in) for one wheel jounce
66
67		1 mm =	0.039	in
68
69		Anti-Roll Spring Rate (One Wheel Jounce) =	((500000(OD4-ID4))/((0.4422A2B)+(0.2264C3)))*MR2
70
71		Anti-Roll Spring Rate (One Wheel Jounce) =	149.102	lb/in
72
73	vi	Front anti-roll spring rate (lb/in) for roll
74
75		Front anti-roll spring rate for roll =	0.5 * Anti-Roll Spring Rate (One Wheel Jounce)
76
77		Front anti-roll spring rate for roll =	74.55	lb/in
78
79	vii	Front anti-roll bar stiffness (ft-lb/deg)
80
81		Front anti-roll bar stiffness =	(Front Anti-roll spring rate for roll * Trackwidth2)/(180/π)
82
83		Front anti-roll bar stiffness =	373.10	ft-lb/deg
84
85	viii	Auxiliary roll stiffness (%)
86
87		Auxiliary roll stiffness (%) =	(Front Roll bar Contribution / Total Front Roll Stiffness at WC) *100
88
89		Front Roll bar Contribution =	Total Front Roll Stiffness - Wheel rate Contribution
90
91		Wheel Rate Contribution =	(Wheel Rate * Trackwidth2)/(180/π)
92
93		Wheel Rate =	(Front Ride rate* Tyre Stiffness)/(Tyre Stiffness - Front ride Rate)
94
95		Wheel Rate =	230.77	lb/in
96
97		Wheel Rate Contribution =	577.47	ft-lb/deg
98
99		Front Roll bar Contribution =	1411.34	ft-lb/deg
100