Volume 7, Issue 2 (March 1979)
Application of Fatigue Life Prediction Techniques to Materials Substitution
The applicability of a computer-based fatigue life predictive technique to materials substitution has been tested by performing a fatigue design analysis on an automobile frame crossmember. The original steel component and an alternate aluminum design were instrumented and installed in a test car, and the vehicle was driven over a standard rough road durability route to record road load histories. The recorded histories were used with a previously developed computer-based predictive technique to obtain component life predictions. Laboratory-program loading of samples of the two materials using the recorded histories confirmed the accuracy of the life predictions. Finally, by taking into account both material property differences and structural design parameters, it was shown that a service history obtained from one component can be used to predict the fatigue life of the component made of alternative materials. This procedure can be of significant value in the consideration of materials substitutions even in situations where design changes accompany the substitution.