EMILIA - A compact impedance analyzer for local integrity assessment

A compact and integrated electronic node for local integrity assessment of a mechanical structure is presented in this paper. The electronic node is referred to as EMILIA (Electromechanical Impedance for Local Integrity Assessment). It consists of an electronic circuit that can be realized as a handheld impedance analyzer for local measurements or directly installed on a piezoelectric patch for performing of distributed monitoring applications. The damage detection of the mechanical structure is based on the method of Electromechanical Impedance (EMI). The EMI requires only a single piezoceramic transducer for in order to monitor a local part of a structure in the vicinity of the transducer. The developed impedance analyzer can perform free adjustable impedance and optional temperature measurements of the observed structure. To verify the accurate operation of EMILIA, laboratory measurements with a high precision impedance analyzer as reference were performed and compared with measurements of the electronic node carried on an aerospace compliant structure of carbon fiber reinforced plastic (CFRP). Additional, detection of added mass next to a piezoceramic transducer applied to a CFRP-panel was realized with the EMI-node.