Distributed computing strategy for structural health monitoring

Monitoring of complex structures to provide real-time safety and reliability information regarding the structure poses significant technical challenges. To detect damage in large civil infrastructure systems, densely distributed sensors are expected to be required. Use of traditional wired sensors is challenging for such applications because of the cost and difficulty in deploying and maintaining a large wiring plant. Using wireless sensor network is also difficult because large amounts of measured data need to be transferred to a central station. The bandwidth and power requirement to transfer these data may easily exceed the limit of the wireless sensor. Recently rapid advances in smart sensor technologies have made damage detection using a dense array of sensors feasible. The essential feature of a smart sensor is the on-board microprocessor, which allows smart sensors to make decisions, perform computation, save data locally, etc. By conducting a portion of the computation at the sensor level, only limited information needs to be transferred back to a central station. However, damage detection algorithms which can take advantage of the distributed Computing environment offered by smart sensors are currently limited. In this paper, a new distributed computing strategy for structural health monitoring is proposed that is suitable for implementation on a network of densely distributed smart sensors. In this approach, a hierarchical strategy is proposed in which adjacent smart sensors are grouped together to form sensor communities. A flexibility-based damage detection method is employed to evaluate the condition of the local elements within these communities by utilizing only locally measured information. The damage detection results in these communities are then communicated with the surrounding communities and sent back to a central station. Numerical simulation demonstrates that the proposed approach works well for both single and multiple damage scenarios. Copyright (c) 2005 John Wiley & Sons, Ltd.