Structural Health Monitoring and Remote Sensing of Transportation Infrastructure Using Embedded Frequency Selective Surfaces

摘要

Frequency Selective Surfaces (FSS) have long been used in the RF/microwave community to control Radar Cross-Section. The scattering parameters of the FSS form a signature which is a function of the frequency, element size and spacing, as well as the local electromagnetic environment, but with proper design is largely independent of angle. These attributes can be related to engineering parameters of a transportation structure such as strain, temperature, moisture, and damage such as cracking or delamination. We will integrate a FSS into a structure (initially on the surface and eventually embedded within layers). This will allow the properties of the structure to be remotely detected. This application of FSS has significant potential for Structural Health Monitoring (SHM). For example the strain on gusset plates as well as other parts of a bridge can be detected from a considerable standoff. Other applications that will be considered are embedding FSS into concrete or composites. Each of these require effective manufacturing approaches which we will begin to develop. After implementation, a in service component can be quickly and remotely interrogated for damage, initially using standard microwave network-analyzer/antennas. Additional localized inspection can be performed on an asneeded basis to determine more detailed information regarding local strain field (or other relevant parameters).