| Civil engineers over the past centuries have made significant strides in designing and constructing safer, more reliable structures. However, the bridge and building portions of the civil engineering community have yet to incorporate explicit methods for treating cracks into their mainstream design codes. Numerous bridge collapses in the late 1960s to early 1970s and the more recent Northridge earthquake fractures show that the community has a significant need for an improved design framework: a paradigm of design that treats cracks explicitly. Thus dissertation provides such a framework.; Based on the physics of failure, this work presents the Holistic Structural Integrity framework currently being developed in the aerospace industry and then adapts it to civil engineering. After discussing the need for an improved framework, this work presents an overview of the four stages of crack growth: nucleation, “small” crack, “long” crack, and final instability. It then presents a review of numerous tools for treating cracks, with heavy emphasis on similitude and fracture mechanics principles. Part 3 changes the focus of the dissertation to the practical application of the framework to weld discontinuities and includes various worked examples and parametric studies. |
