COVER SHEET Title: Design Framework for Vibration Monitoring Systems for Helicopter Rotor Blade Monitoring using Wireless Sensor Networks

The pursue of methods for supporting Structural Health Monitoring (SHM) has been an important driver for the technological innovation in several engineering fields such as wireless communication, sensing and power harvesting. However, despite of the innovative and scientific value of these advances, the adoption of SHM and associated technologies by industry has not occurred at the expected pace. One of the possible reasons for this is the lack of a systematic design process for condition monitoring systems tailored to actual mechanical systems. This paper proposes a design framework for a vibration monitoring system that integrates the predictive maintenance needs with the technological developments on SHM methods and related technologies. The framework involves three stages. The first stage corresponds to the identification of the characterization of the system function and its failure and the expected function of the monitoring system. The next stage aims at decomposing the vibration signal according to the dynamic behavior of the system and associated failure. The last stage corresponds to the technological implementation of the vibration monitoring system. To illustrate the applicability of this framework a case study on the development of a vibration monitoring system for helicopter rotor blades by using an autonomous sensor network is presented.