Structural Integrity Using Vibro-Acoustic Modulation (VAM) to Extend the Lifetime of Civil Infrastructure

Motivation

Vibro-acoustic modulation (VAM) is a promising novel method for non-destructive testing for fractures and fatigue of a variety of materials using ultrasound. Similar to a long-term ECG for a human, continuous and detailed monitoring of the "structural health" of civil infrastructure can detect small defects—so called micro-fissures—early; i.e., even before macroscopic and visual damage such as cracks evolves. It is hence possible to increase safety while also drastically reducing the cost of maintenance and prolonging the lifetime. By collaboration of researches from the domains of material science, computer science, and electrical engineering, continuous monitoring can be achieved effectively, using tiny sensors, The latter periodically produce an acoustic signal at one location and record and analyze the received signal at a different location in the same structural element. With recent progress in exploiting environmental energy sources such as solar or vibration for miniature sensing devices—equipped with wireless communication devices to transmit their measurements—setup and maintenance costs of such monitoring systems are drastically reduced. Meanwhile, non-invasive and facile sensor installation is achieved.

Goals and Contributions

A collaboration of the Institute of Polymer and Composites, the Institute for Metal and Composite Structures and the Institute smartPORT at Hamburg University of Technology (TUHH) will carry out research in multiple fields to work towards the cost effective, custom monitoring solution described above. The goals include gaining new insights into the VAM method and the initiation of cracks in general as well as automated investigation of the sensor results using artificial intelligence technologies. The focus of the institute smartPORT embraces research and methods and algorithms for energy-autarkic sensing and data preprocessing and the development of a wireless, low-cost and self-sustained embedded prototype. In particular, research challenges are reliable computing while tolerating of fluctuating power supply from energy harvesting (transient computing) and synchronization of such sensor nodes for simultaneous measurements in order to not identify but also localize defects.