REDUCTION OF UNCERTAINTIES IN SHM DATA TRANSMISSION AND FAILURE ANALYSIS WITHIN LIMITATIONS TO ECONOMIC AND SAFETY ASPECTS

Abstract

In Clean Sky 2 project DEMETER the potential of Structure Health Monitoring (SHM) is investigated in the context of Condition Based Maintenance. Data generated through SHM systems can be managed by Direct or Indirect measurement techniques. Indirect measurements comprise of selecting physical parameter or signals which have a negative effect on structural load and stresses like g-force or differential pressure. For the usage in SHM solutions physical data need to be collected, stored, transmitted and transferred to structural load models. Therefore, the concept proposed in this paper deals with a generic approach for tolerances and failure calculation with an extension of analysis on their negative effects over indirect measurements. The failures and remaining usage of the structure taken into consideration will be calculated, wherein magnitude of different failure rates will also be depicted. This will be followed by defining and analysing the limitations that could be caused due to implementation .of indirect measurements. In this study A320 engine mount bolts subjected to CBM program are analysed. For the proposed indirect SHM systems existing components in the aircraft are used and no design changes on the aircraft are planned. This may further emerge problems with design integrity of the existing components, which in turn bring restrictions to the use of health management and adds uncertainties via the data generated by structure health monitoring systems. The results will give possible recommendations to reduce the confidence interval with the usage model developed and therefore increasing the benefit of the health monitoring approach proposed.