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 formulati...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.展开更多
文摘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.
