Microwave Structural Health Monitoring Sensor for Deformation Measurement of Bended Steel Structures: Influence of Curvature Effect

In this paper the utilization of microstrip antenna sensor for deformation monitoring in bended steel structures is presented. This kind of sensing element can be used in structural health monitoring systems. Deformation measurement by patch sensor is based on the reflection coefficient S11 investigation. So far, relationship between resonant frequency and change of patch dimensions was considered in literature only for planar microstrip sensors. In case of samples subjected to bending process the sensor geometry became non-planar. This fact affects measured resonant frequency, thus it should be studied. In order to analyze influence of patch sensor curvature on resonant frequency during bending process Finite Element Method (FEM) simulations were carried out. Results of analysis were experimentally verified.