PITA Fiscal Year 2011 Projects

Implementation and Instrumentation Strategies for In-Service Bridge Performance Evaluation Using Finite Element Models     

Lead University: Lehigh University
PI: Shamim N. Pakzad, Department of Civil and Environmental Engineering
Co-PI(s): John L. Wilson, Department of Civil and Environmental Engineering
PA Industry: Specialty Engineering, Inc

The application of newly developed wireless sensor network (WSN) technology in structural health monitoring is a focal point of research and development. Integration of this technology in a structural monitoring and maintenance system requires that several key questions in data collection, analysis, and modeling be addressed. The proposers have completed several studies on hardware design for accelerometer and strain gauge wireless sensing networks, system software for reliable communication and rapid flow of data and information in a WSN, on-board and central analysis of the data and comparison with mathematical models of the monitored structures. A significant area of related research is the integration of WSNs with advanced mathematical models of the structure to accurately diagnose its condition and provide prognosis for its future behavior and maintenance. A class of such mathematical methods is finite element models, which are widely used in the design and retrofit stages of structures, but are often not verified and validated by measured data. The proposers have identified three categories of finite elements model updating using sensor data as the focus of their research: model updating for stochastic systems, model updating for input/output systems, and adaptive model filters for online real-time updating.

There are important related questions that need further studies and testing. One of these issues is the implementation and instrumentation strategies for optimizing the efficiency of the system in three critical categories:

  1. accurate detection of structural damage and deterioration;
  2. energy management for a WSN system with limited power resources; and
  3. strategic flow of data and information in a wireless network having a limited communication capacity.

Determination of the number and location of sensing devices and its affect in the performance of the monitoring system is an issue that has not been studied and has important implications in their feasibility and efficiency. The focus of this project is in addressing these issues in the context of finite element model updating. The proposed project is a natural outgrowth of our current research on finite element model updating using sensor data for bridge performance evaluation. The expected results of this study will enhance the efficiency and accuracy of SHM systems using WSN and improve the safety and performance of bridge infrastructure.