Measurement and Simulation of Random Vibro-Impact Responses at Brake Guide Pins

Abstract

This study firstly conducted measurement of load history profiles at brake guide pins using strain gages subject to random road load history obtained from vehicle durability tests. Then, this study developed a simple mathematical model capable of estimating guide pin load history using the principle of energy conservation for a given road load profile. The model took into account the effect of impact that occurs from a range of acceleration levels and frequency content of the road input. The mathematical model also utilized the measured stiffness of the guide pin specimens and strain versus load relationship to increase the accuracy of the predictions. The estimated loads at a brake guide pin subject to a given random road load history were then computed using the mathematical model and compared to the load history obtained from the measurement. This study also compared cumulative fatigue damages calculated using Smith-Watson-Topper equation with the measured and predicted load profiles at the guide pin. The comparison study showed that the developed simple model is applicable to predict load profiles for fatigue life calculation at brake guide pins.