Structural alterations to bridges may result in unintended consequences up- or downstream, such as changes in discharge, velocity, stream power, and water levels. This work presents a framework and methodology to analyze interconnected bridge-stream interactions under flood conditions. Such analysis may help prioritize limited resources available for bridge and river rehabilitations, facilitate holistic design of bridges and better-informed cost/benefit analyses, and address stakeholder concerns raised in response to planned bridge and infrastructure alterations.
View Article and Find Full Text PDFTurtle shells comprising of cortical and trabecular bones exhibit intriguing mechanical properties. In this work, compression tests were performed using specimens made from the carapace of Kinixys erosa turtle. A combination of imaging techniques and mechanical testing were employed to examine the responses of hierarchical microstructures of turtle shell under compression.
View Article and Find Full Text PDFNacre, a composite made from biogenic aragonite and proteins, exhibits excellent strength and toughness. Here, we show that nacreous sections can exhibit complete brittle fracture along the tablet interfaces at the proportional limit under pure shear stresses of torsion. We quantitatively separate the initial tablet sliding primarily resisted by nanoscale aragonite pillars from the following sliding resisted by various microscale toughening mechanisms.
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