Fatigue sensor for structural health monitoring: Design, fabrication and experimental testing of a prototype sensor

摘要

Fatigue damage monitoring of any structure is a prerequisite for reliable and effective structural health prognosis. A novel fatigue sensor for detecting and monitoring the fatigue damage and estimating the remaining life of machine components and structures subjected to cyclic loads is discussed. The fatigue sensor consists of alternate slots and strips having different strain magnification factors with respect to the nominal strain at the location where it is placed on the structure. The sensor experiences the strains which closely resemble the actual strain distribution in the critical area of the component. The sensor can be placed away from the notch-root stress concentration region at a convenient location on the structure but would still experience the same fatigue damage as the notch-root. The strips fail in a sequential manner from the strip experiencing the highest strain magnification to the lowest. Each strip failure corresponds to the particular fatigue damage accumulated by the structure being diagnosed. This information allows for predicting remaining component life. The design of the fatigue sensor is validated by the elastic and elastic-plastic finite element analysis simulations. The finite element analysis (FEA) simulations were performed in 2D and 3D configurations. This paper describes different aspects of the fatigue sensor design, analytical modeling, FEA simulation, fabrication, and experimental testing along with the results. Copyright © 2015 John Wiley & Sons, Ltd.