Phased and Synchronous Sampling Between Multiple Smart Network Sensors for Modal Assessment of Large Structures

Abstract

Operational modal analysis and vibration-based damage detection of engineering structures have become important issues for Structural Health Monitoring (SHM) and maintenance operations. For this task, embedded wireless platforms such as the PEGASE platform are appealing and suitable to collect vibration data and then perform off-line and remote computation easily. To obtain detailed modal information of large and very large structures, many sensors would be required to cover the geometry of the structure with a reasonable accuracy. However, when only a limited amount of sensors is available, large structures can be measured in several sensor setups, where some sensors remain fixed and some are moved between different measurement setups. With the sensors connected to different wireless platforms, the synchronous acquisition of data is required. In this paper, a solution of data acquisition synchronization, as well as signal processing for merging the information taking into account the change of sensor positions and environmental variability is presented.