Stress Testing Methods in Body Structures

SINCE theoretical and empirical engineering formulas do not always apply to automobile body structure, reliance must be put on structural testing to supplement available information. In this paper the author presents a technique for complete car structural and road testing in conjunction with body tests for such purposes as:

1. 1.
   Aiding development of experimental body designs.
2. 2.
   Assisting in the standardization of quality control methods.
3. 3.
   Solving special problems in fabrication.
4. 4.
   Furthering the improvement of body-frame unit structural efficiency.
5. 5.
   Investigating the use of new materials.
6. 6.
   Determining safety factor of body.

The search for adequate methods of determining the safety factor led to the development of the roll-over test. It is accomplished by towing a car so that the wheels on one side go up a ramp at a 15-deg angle, and at a speed of 50 mph. The car is rolled in such a manner that the windshield header receives the greatest impact.