1. Head on Collision By Fabiola Carrasco ME 143 Professor Granda December 25, 2006

2. Introduction  There are thousands of automobile collisions everyday and many of those are fatal head on collisions  An example of that type of accident occur regularly in Placer County on Walerga Road near PFE Road.  There have been at least a couple of single car accidents that collide with the trees on the side of the road that have resulted fatal

3. Working Model Simulation  To start the simulation we need the automobile, the obstacle (tree), the ground and the person in the car.  The automobile was created with the polygon tool.  The wheels are just circles and each is attached to the body of the automobile by pin joints

4. Working Model Simulation (Cont)  The curved polygon was used to do the seat of the car and it was attached to the automobile with two rigid joints  The dummy was crated using 5 curved polygons that were connected with pin joints and rotational springs at each joint  The ground and obstacle are just rectangles that are fixed to prevent them from moving

5. Working Model Simulation (Cont)

7.  To show the acceleration, velocity, and position graphs of the most critical part of the dummy - the head, I simply clicked on the head and used Measure from the tool bar and picked the desired measurement from the drop menu  Since most of the accidents that I was interested in that had occur on Walerga road were at high speeds, I assigned the car, the seat and the dummy’s velocity to 70mph

8. Working Model Simulation Conclusion  When the simulation is played the dummy leans forward and crashes on the windshield  This indicated the accident is fatal since the person is not likely to withstand the high impact of the collision  Seatbelts were not used in this simulation which made the collision fatal since there was no restrain to prevent the dummy from hitting the windshield or flying out of the car

9. Nastran 4D Simulation  I stated the simulation in Nastran 4D by inserting the ground or floor.  Next I inserted a solid works file that contained a sketch of make believe car

10. Nastran 4D Simulation (Cont)

11.  I proceeded to create the dummy but ran into problems with the constraints and could not develop this simulation any further

12. Conclusion  Simulations using Working Model 2D and Nastran 4D are very helpful in understanding the impact of an automobile accident  The draw back is that one must be proficient enough in using these programs in order to achieve the desired results