Numerical Analysis of the C* Fracture Test Specimen using the Generalized Finite Element Method

The experimental assessment of cracking distresses in asphalt concrete pavements is crucial to the longevity of pavements. As such, fracture parameters obtained from experiments play a key role in facilitating the use of fracture mechanics theories and prediction of cracking distresses in asphalt concrete (AC) pavements. The stress intensity factor (SIF) is among the fracture parameters derived from fracture mechanics theory. Many fracture mechanics based laboratory tests have been developed with the goal of calculating such key fracture parameters. The C* Fracture test is unique among them because it incorporates rate dependent loading into the calculation of fracture parameters via the theory of the C* Line integral. However, unlike other laboratory fracture tests, the C* Fracture test does not have any analytical solution or previous sources from literature which describe geometric shape factors used in the calculation of SIFs. Numerical modeling of the C* Fracture test specimen is also limited in literature. Therefore, there is a need for a high-fidelity numerical model of this fracture test in order to develop SIF functions. In this thesis, the numerical models of the C* Fracture test were developed using the Generalized Finite Element Method (GFEM). GFEM is particularly effective at modeling problems with discontinuities in complex 3-D structures. The use of the GFEM to solve this problem allows a high-fidelity numerical model to be created without a large computational cost and labor intensive mesh crafting. After verifying the model accuracy using convergence analysis, the specimen geometry was modeled by changing the crack size. A SIF function was developed that includes a specific geometry dependent shape factor for the C* Fracture test based on Linear Elastic Fracture Mechanics (LEFM).