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Wear Aging and Related Impact on System Reliability



Deterioration processes occurring within two moving surfaces of tribological system manifested through the loss of material or any other material change are defined as wear. In this contribution, the analysis of wear is indispensable in terms of wear rate decrease as the point in time at which the system becomes nonfunctional. It is assumed that this moment in time can be postponed by ensuring lower wear rate. The technical system concerned in this contribution as example is a wind turbine system (WTS). The analysis of wear mechanisms herein is carried out taking into consideration critical components of WTS. Concerning this the most attention is attracted to thermal, mechanical, and chemical aspects of wear processes occurring in critical components and contributing to the loss of functionality due to related aging. The failures appearing within wind turbine systems as well as corresponding decrease in WTS reliability are intensively inferred in recent years. A number of reliability databases have ensued targeting to obtain detailed knowledge of failure causes and failure modes with special emphasis to the correlation of failure modes to applied loads. Using benchmark data stored in reliability databases, the identification of critical components concerning the failure occurrence frequency, the number of system downtimes, mean time between failures, as well as related additional reliability parameters is facilitated. In this contribution, the focus is given on wear process of rotor blades and bearings. The wear modes briefly introduced herein are associated with aforementioned components. The idea lies behind gaining the knowledge about actual system’s state is the modeling of deterioration processes. Finally, the options for adapted operating conditions targeting to achieve decreased deterioration rate are pointed out.

doi: 10.12783/SHM2015/353

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