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. Wear and friction behavior of tribo-components experiencing variable speeds is investigated both experimentally and computationally. Experiments involve a collection of pin-on-disk tests with constant loads at varying speeds, and predictions are made by using continuum damage mechanics (CDM). Extensive experimental results under a series of sequentially-variable speed scenarios reveal that the cumulative power consumption up to the instant when failure occurs remains relatively constant regardless of the types of sequential loadings and speeds. It is also shown that CDM can properly predict the coating wear whereas Archard’s equation does not provide satisfactory results when the operating speed is sequentially varied.

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محمدرضا فروزان , محسن اصفهانيان