The structural reliability of many brittle materials such as structural ceramics relies on the occurrence of intergranular, as opposed to transgranular, fracture in order to induce toughening by grain bridging. For a constant grain boundary strength and grain boundary toughness, the current work examines the role of grain strength, grain toughness, and grain angle in promoting intergranular fra...

Danshui River estuarine system is the largest estuarine system in northern Taiwan and is formed by the confluence of Tahan Stream, Hsintien Stream and Keelung River. A comprehensive one-dimensional model was used to model hydrodynamics and cohesive sediment transport in this branched River estuarine system. The applied unsteady model uses advection/dispersion equation to model the cohesive sedi...

This paper investigates the force transmission modes, mainly described by probability density distributions, in non-cohesive dry and cohesive wet granular materials by discrete element modeling. The critical state force transmission patterns are focused on with the contact model effect being analyzed. By shearing relatively dense and loose dry specimens to the critical state in the conventional...

Most quasi-static variational models of fracture are based on the splitting of the energy functional into the sum of two terms: bulk, depending on the displacement gradient, and surface, depending on the displacement discontinuities. In this paper we consider the simplest one-dimensional problem of this type, a bar stretched by a given axial displacement, and systematically compare two alternat...

This study identifies and assesses the controls on hydraulic erosion of cohesive riverbanks on a 600-m reach of an urban ephemeral stream with active bank erosion. We examined hydraulic bank erosion by separating estimated bank shear stress into four properties: magnitude, duration, event peak, and variability. The values of these independent variables were used as a bank erosion context at thr...

Social communities have drawn a lot of attention in the past decades. We have previously introduced and validated the use of the cohesion, a graph metric which quantitatively captures the community-ness in a social sense of a set of nodes in a graph. Here we show that the problem of maximizing this quantity is NP-Hard. Furthermore, we show that the dual problem of minimizing this quantity, for ...