Crash Tester – Impulse Momentum

Crash Tester Example Experiemnt

This short example will show you the data collected by the crash tester and the Labview software and how simple changes in the car starting point and the barrier result in big changes in "G" forces and velocities.

Click on any of the screen shots for a larger complete view of the computer screen.

Crash 1

The Crash Car was let go at the top of the hill into a 10 mm foam barrier.

The important data is the Max Impact G’s (63.25) and The Velocity (2.932 m/sec) at impact. Velocity was calculated by measuring the time between two flags (0.1254 sec) 30.0 cm apart before impact. Note the width of the graph, the lower portion to the graph is time. The width of the graph or time of impact is a result of the crash cars impact being absorbed by the crushing of the foam. The difference between the start and end of the graph is when the car first impacts the foam and when it stops.

An expanded look at the graph from Crash 1 using Labview’s Zoom in tool. This feature allows for a more advanced analysis of the final crash data. Once again note the width or time of the impact.

Crash 2

The crash car was let go approximately 5 cm from the bottom of the hill into a solid barrier.

Note the Impact G’s (100.25) and the Velocity (0.916 m/sec). Once again note the width of the graph. This explains the high G impact force from such a slow velocity. Impact occurred over a very short time (Delta T). By the car impacting a solid wall there was very little energy absorbed. The entire force of impact was transferred directly to G force at impact.

An Expanded look of the graph from Crash 2.