Crack propagation is a very critical process in both reflective- and fatigue-cracking distress mechanisms. Computation of the stress intensity factor (SIF) at the crack tip provides the basis for crack propagation analysis. Due to three-dimensional (3D) nature of a cracked pavement and traffic loading, the best choice of calculating the SIF is 3D finite element (FE) programs. However, the 3D FE solutions are often very expensive due to large number of equations and matrix with comparatively large bandwidth. Sometimes 3D analyses may overload the available computer capability when the pavement structure is too complex. To address the aforementioned problems, a new FE analysis package named "SA-CrackPro" was developed and is discussed in this paper. SA-CrackPro is essentially a 2D SIF calculation program that incorporates a Semi-Analytical (SA) method. SA-CrackPro can provide the same satisfactory computations and results as a 3D FE program at a much faster speed and with much fewer computer resource requirements. To simulate the pavement layer interface and load transfer conditions at the joints (or cracks), thin-layer elements were introduced. To sufficiently and accurately model crack propagation, FE auto-meshing and re-meshing techniques were proposed and implemented in the program. The accuracy of the program was verified through comparisons with a commercial 3D FE package, ANSYS. Finally, the application of the program is demonstrated to conclude the paper.
Abstract