Investigation of Fracture Behavior of Heterogeneous Infrastructure Materials with Extended-Finite-Element Method and Image Analysis

Infrastructure materials are essential components of the nation's infrastructure and transportation systems. Deteriorating infrastructures require the development of computational tools to predict fracture behavior. The extended-finite-element method (XFEM) has been recently developed to eliminate remesh efforts by allowing crack propagation within continuous elements. The object of this study is to employ XFEM and image analysis techniques to numerically investigate fracture behavior within infrastructure materials. The XFEM was addressed with a discontinuous crack and inclusion enrichment function with the level-set method. The crack growth and stress intensity factors were also formulated. An extended-finite-element fracture model (XFE-FM) was developed with the MATLAB program for predicting fracture behavior with single-edge-notched beam (SEB) and split tensile (ST) tests. The developed XFE-FM was first validated with SEB testing on a homogeneous sample. In order to capture the real material microstructure, the digital samples of asphalt concrete and concrete specimens were generated with imaging processing and ellipse-fitting techniques. The predicted crack propagation with XFE-FM simulation on digital samples was compared with the fracture pattern of lab-tested specimens. The comparison results on open-mode middle-notched and mixed-mode offset-notched SEB and ST tests indicate that the developed XFE-FM has the ability to accurately predict fracture behavior within heterogeneous infrastructure materials. DOI: 10.1061/(ASCE)MT.1943-5533.0000337. (C) 2011 American Society of Civil Engineers.