1. Vehicle Crash Test Lab Justin Otero Fall 2007
ME270 Prof. Granda
Vehicle Crash Test Lab
Justin Otero
Fall 2007

2. I | SF—1—-0—-1—-0—-1—-I | | R—1--C R--1--C
First thing done was to create a bond graph then enter into CAMP-G software
I | SF—1—-0—-1—-0—-1—-I | | R—1--C R--1--C

3. Causality and Equations were then derived from the bond graph and verified in CAMP-G
SF1=f1 f2=f1 e5=Q5/C5 f7=P7/I7
f8=f7 e11=Q11/C11 f13=P13/I13 f6=f7
f12=f13 f3=f2-f6 f4=f3 f5=f3
f9=f8-f12 f10=f9 f11=f9 dQ5=f5
dQ11=f11 e4=f4*R4 e10=f10*R10 e3=e4+e5
e6=e3 e9=e10+e11 e12=e9 e13=e12
dP13=e13 e2=e3 e8=e9 e1=e2
e7=e6-e8 dP7=e7

4. Using MATLAB the variables were designated as;
e=force
f=velocity
Q=displacement
P=momentum
R=damper value
C=spring constant
I=mass

5. Using MATLAB a simulation was run and two graphs were plotted using the given variables.

6. The values were modified to run a simulation of a vehicle crashing at 25mph and 55mph.
Graphs were plotted to get the displacement and forces being exerted on the dummy.

7. A Simulink diagram was created in MATLAB to verify the System State space equations.

8. Here is the comparison of the MATLAB campgnum.m to the simulink scopes.

9. The best design for a bumper and seat belt combination to survive a crash at 55mph.
Bumper: Seat Belts:
Spring Constant = 500K Spring Constant = 150K
Damper Value = 50K Damper Value = 25K
These Values produce results no greater than 2743 lbs of force per seatbelt and 81 cm of displacement for the dummy.