1. ME 270 Vehicle Analysis
By: Kevin McClain

2. ME 270
Objective
Develop a mathematical model of a vehicle for simulation using CAMP-G and Matlab.
Analyze the system for the following parameters.
Ensure driver does not hit the windshield
Determine if fatal injuries occur at speeds of 25 mph and 55 mph
Determine the “critical” speed at which the driver is not injured.

3. ME 270 Camp G Bond Graph system representation SF 1:vo 1:v2 1:v1 I:m
*Illustration represents bond graph for single belt, Causalities not shown SF
1:vo
1:v2
1:v1
I:m
I:M
R:b2
C:k2
R:b1
C:k1

4. ME 270 Matlab Select Matlab in the interface menu of Camp G
Camp G opens Matlab
At Matlab command prompt, enter “Campgmatlab”
Select the “campgmod” tab and enter the system parameters and variables.

5. ME 270 Matlab System Parameters Vehicle Seat Belt Mass [M] = 1,500 kg
Bumper, Damper Rate [b2] = 80,000 N-s/m
Bumper, Spring Rate [k2] = 300,000 N/m
Seat Belt
Damper Rate [b1] = 500 N-s/m
Spring Rate [k1] = 10,000 N/m

6. ME 270 Matlab System Parameters cont. Driver Mass [m] = 100 kg
Force on Driver Cannot Exceed 1,500 lbf (6,672 N)
Displacement of Driver Cannot Exceed 100 cm (1 m)

7. ME 270 Matlab System variables System Initial Conditions Q5IN = 0
P13IN=100*25*
P7IN=1,500*25*
Initial = [Q5IN; Q11IN; P13IN; P7IN]

8. ME 270 Matlab System Variables cont. System Parameters R4 = 80,000

9. ME 270 Matlab System Variables cont. External System Inputs
Global Source Flow 1
SF1 = 0
Simulation Time Control
T0 = 0
Tf = 5

10. ME 270
Matlab

11. ME 270
Matlab
Model 55mph

12. ME 270 Analysis 25 mph, One and Two Seat Belts
Driver will NOT contact windshield
Force on Driver is NOT fatal.
55 mph, One and Two Seat Belts
Driver WILL contact windshield
Force on Driver IS fatal.

13. ME 270 Analysis cont. Critical Velocity, One Seat Belt
Driver will not contact windshield and force on driver does not exceed allowable force at a speed of mph
Critical Velocity, Two Seat Belts
Driver will not contact windshield and force on driver does not exceed allowable force at a speed of mph

14. ME 270 Analysis cont. Time to Windshield w/o seatbelt
55mph, contact at .058 seconds
40mph, contact at .065 seconds
25mph, contact at .1 seconds