Structural health monitoring of precracked structures using an in-plane inverse crack-tip element  

作　　者：Ihtisham Khalid Zahid Ahmed Qureshi Hafiz Qasim Ali Selda Oterkus Erkan Oterkus 

机构地区：[1]Department of Aerospace Engineering,College of Aeronautical Engineering,National University of Sciences&Technology,Islamabad,Pakistan [2]Department of Naval Architecture,Ocean&Marine Engineering,University of Strathclyde,Glasgow,Scotland,UK

出　　处：《International Journal of Mechanical System Dynamics》2024年第4期406-426,共21页国际机械系统动力学学报(英文)

摘　　要：This study investigates the application of the inverse finite element method(iFEM)in fracture mechanics by developing a novel two-dimensional six-node triangular inverse crack-tip element.With its simplified formulation,the proposed inverse element is computationally efficient and ensures strain singularity at the crack tip by repositioning midside nodes.Its displacement-based stress intensity factor(SIF)computation methodology integrates seamlessly with the existing iFEM framework,making it highly suitable for real-time health assessment of structures with preexisting cracks.The inverse element has been rigorously validated for shape-sensing and mixed-mode SIF calculations by considering various crack geometries and mixed-mode loading conditions.The triangular inverse element demonstrates superior flexibility in handling structured and unstructured discretizations in mapping regular and complex geometries,particularly high-stress gradient areas like crack tips.The study also explores the variational least squares method for optimal sensor placement within the inverse element domain,ensuring accurate shape-sensing and SIF computations with fewer onboard strain sensors.The proposed inverse formulation,with its accurate shape-sensing capabilities and precise reconstruction of fracture parameters,represents a significant advancement in the real-time Structural Health Monitoring of engineering structures with pre-existing cracks.

关 键 词：structural health monitoring stress intensity factor shape-sensing crack tip iFEM 

分 类 号：O34[理学—固体力学]