Application of Continuum Damage Mechanics for Prediction of Wear with Provision for Sequential Speed Operation

An experimental procedure and a thermodynamic methodology are presented to evaluate adhesive wear for systems experiencing variable and sequential speed. Continuum damage mechanics (CDM) estimates the probability that an asperity forms a wear particle and uses this information to derive an expression for the wear coefficient. Experiments involve an extensive set of pin-on-disk tests with constant loads at a sequence of ascending, descending, and arbitrarily varying speeds. The applicability of the Miner's rule that calculates the cumulative damage in cyclic fatigue with variable loading amplitudes and CDM method for determining wear coefficient in sequential speeds is investigated. The results show that the constant value of Miner's rule in experiments with ascending velocity is less than in descending cases. It is also shown that the measured weight loss and wear coefficient results agree with those predicted via CDM. In cases in which single load or single speed is applied, Archard law-which states that the wear volume is proportional to the applied load and sliding distance and inversely proportional to the hardness of the material-can predict the wear volume with an error of less than 15%. In contrast, in situations where the tribo-system system experiences variable speeds, Archard's law does not provide satisfactory results.

Automated summary

This paper presents an experimental procedure and a thermodynamic methodology for evaluating adhesive wear in systems with variable and sequential speeds. The continuum damage mechanics (CDM) is used to estimate the probability of asperities forming wear particles and derive the wear coefficient. The results show that the wear coefficient in descending cases is higher than in ascending velocity experiments. Additionally, Archard's law is not suitable for predicting wear volume in situations with variable speeds.