Development and Validation of a Tree-Ring Bio-Inspired Wireless Fatigue Monitoring System

Abstract

Fatigue, which may cause sudden failure of the critical structures, has been a key problem for the aircrafts and railway systems for centuries. With uncertain loading conditions, the fatigue life of the involved structure is inherently random and few sensing techniques are reliable for long-term monitoring of fatigue damage. This paper proposes a novel intelligent system targeted at fatigue damage monitoring of in-situ structures with online structural health monitoring. The developed intelligent system combines the concepts of tree-ring bio-inspired data track technique with the real-time wireless structural health monitoring (SHM) sensing technique. A general framework, the methodology, and the strategy of the intelligent fatigue monitoring system are investigated in details. The rain-flow counting method is adopted as the core algorithm for determining the fatigue damages from detected structural behavior parameters under various loading conditions. The employment of the Digital Signal Processing (DSP) is then followed as the core data processing module to collect and analyzed the monitored fatigue damages. Laboratory test results show that the developed intelligent fatigue monitoring system can provide a reliable and quick feedback and warning of fatigue failure. Therefore, with the advantages of low cost, ease for handling and installation, simple concept, high accuracy, and great reliability, the proposed tree-ring bio-inspired wireless fatigue monitoring system can be further applied to practical applications such as in mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, and energy related structures.