A Flexonic Magnetic Car for Ferro-Structural Health Monitoring

This paper presents a new magnetic car as a mobile sensor node for health monitoring and dynamic testing of large civil (ferromagnetic) structures. Unlike traditional car design where the distance between the front and rear wheel pairs is fixed, the electromagnetically driven compliant beam (connecting the front and rear axles) not only offers an effective means to negotiate corners and cross ridges of small dimensions when maneuvering on ferromagnetic surfaces, but also serves as a sensor attachment device. Specifically, this paper presents the design concept of a novel flexonic magnetic car incorporating compliant beams and permanent magnets, and a three-dimensional model for simulating the deformed shape of the compliant beam. The compliant beam that enables direct contact of the accelerometer with the measuring surface eliminating the dynamic effect of the sensor carriers has been validated with the experimental modal analysis for a frame structure. This represents a transformative change from the fixed spatial resolution provided by traditional static sensors.