Head-on Head-on CollisionCollision

ME115ME115FALL 2006FALL 2006

Final ProjectFinal Project

Instructor:Instructor:Professor GrandaProfessor Granda

ByByBlong XiongBlong Xiong

Department of Mechanical EngineeringCalifornia State University, Sacramento

ObjectiveObjective

Create a dummy in solid works and Create a dummy in solid works and export it into Nastran 4D for export it into Nastran 4D for simulation. The dummy is set in the simulation. The dummy is set in the driver seat of a vehicle that driver seat of a vehicle that simulates a head-on collision with a simulates a head-on collision with a wall. There are not airbag wall. There are not airbag simulations and the dummy will not simulations and the dummy will not have any seatbelts on.have any seatbelts on.

ProcessProcess

FirstFirst Create a dummy and car seat in solid Create a dummy and car seat in solid

works.works.

Body Parts created in Body Parts created in Solid WorksSolid Works

BodyBody

HeadHead

Body Parts (cont)Body Parts (cont)

ArmsArms

Fore-armsFore-arms

Body Parts (cont)Body Parts (cont)

HandsHands

ThighsThighs

Body Parts (cont)Body Parts (cont)

ShinShin

FootFoot

Assembled Dummy and Assembled Dummy and SeatSeat

SecondSecond Import the files into Nastran 4DImport the files into Nastran 4D

ThenThen Position the dummy into the vehiclePosition the dummy into the vehicle

AndAnd Fix the constraintsFix the constraints

Dummy placed in vehicle Dummy placed in vehicle and wall is builtand wall is built

NowNow

Set the vehicle to collide with the wall and Set the vehicle to collide with the wall and set the dummy to collide with the vehicle.set the dummy to collide with the vehicle.

The C.O.R of vehicle, dummy, and wall: .5The C.O.R of vehicle, dummy, and wall: .5

The initial conditions of the simulation The initial conditions of the simulation are:are:

vehicle and dummy: 21 m/s or about 48 vehicle and dummy: 21 m/s or about 48 mi/hr.mi/hr.

Get ready to watch the simulation.Get ready to watch the simulation.

Collision videoCollision video

Click picture to Click picture to playplay video video

Collision videoCollision video(close-up view)(close-up view)

Click picture to play Click picture to play videovideo

Simulation Data and Simulation Data and GraphsGraphs

The momentum of the The momentum of the vehicle and dummy vehicle and dummy decrease dramatically decrease dramatically as expected, because as expected, because of the collision with the of the collision with the wall.wall.

However, the However, the momentum of the momentum of the dummy is still dummy is still increasing after the increasing after the initial collision because initial collision because it is still moving inside it is still moving inside the vehicle.the vehicle.

Simulation Data and Simulation Data and Graphs Graphs (cont.)(cont.)

The velocity of the The velocity of the vehicle and dummy vehicle and dummy resemble the resemble the momentum graph. momentum graph. They decrease They decrease dramatically.dramatically.

Simulation Data and Simulation Data and Graphs Graphs (cont.)(cont.)

Right after the Right after the vehicle collision, vehicle collision, the acceleration of the acceleration of the vehicle the vehicle decreases decreases dramatically, but dramatically, but the acceleration of the acceleration of the dummy actually the dummy actually increases rapidly increases rapidly until it hits the until it hits the vehicle.vehicle.

Simulation Data and Simulation Data and Graphs Graphs (cont.)(cont.)

The maximum force on The maximum force on the neck of the dummy the neck of the dummy is 1158 lb. force when is 1158 lb. force when the dummy’s head the dummy’s head collides with the vehicle.collides with the vehicle.

The maximum force on The maximum force on the body of the dummy the body of the dummy is 466 lb. force when it is 466 lb. force when it hits the vehicle. hits the vehicle.

The dummy’s body hit The dummy’s body hit the vehicle before the the vehicle before the dummy’s head, hence dummy’s head, hence the offset of the peaks of the offset of the peaks of the two graphs.the two graphs.

ConclusionConclusion

The vehicle simulation results show that The vehicle simulation results show that a person in a similar collision would a person in a similar collision would suffer major injuries if not death, suffer major injuries if not death, especially, a person without seat belts or especially, a person without seat belts or air-bag protection. The force exerted on air-bag protection. The force exerted on the neck of the dummy is very high. the neck of the dummy is very high.

It is only a simulation of a collision. It is only a simulation of a collision. Many factors were not included or were Many factors were not included or were estimated. The human dummy for estimated. The human dummy for example is created by approximating example is created by approximating weights and heights. weights and heights.

EndEnd