Applied Mechanics Commons^™

A Multi-Scale Homogenization Scheme For Modeling Anisotropic Material’S Elastic And Failure Response, Justin Matthew Garrard

Doctoral Dissertations

The effect of small-scale random defects such as microcracks or inclusions are critical to the prediction of material failure, yet including these in a fracture simulation can be difficult to perform efficiently. Typically, work has focused on implementing these through a statistical characterization of the micro- or meso-scales. This characterization has traditionally focused on the spatial distribution of faults, assuming the material is purely isotropic. At the macro-scale, many materials can be assumed to be fully isotropic and homogeneous, but at the small scale may show significant anisotropy or heterogeneity. Other materials may be effectively anisotropic in bulk, such as …

Strain-Based Design Methodology Of Large Diameter Grade X80 Linepipe, Mark D. Lower

Doctoral Dissertations

Continuous growth in energy demand is driving oil and natural gas production to areas that are often located far from major markets where the terrain is prone to earthquakes, landslides, and other types of ground motion. Transmission pipelines that cross this type of terrain can experience large longitudinal strains and plastic circumferential elongation as the pipeline experiences alignment changes resulting from differential ground movement. Such displacements can potentially impact pipeline safety by adversely affecting structural capacity and leak tight integrity of the linepipe steel.

Planning for new long-distance transmission pipelines usually involves consideration of higher strength linepipe steels because their …