1 The Effect of Cohesive-Law Parameters on Mixed-Mode Fracture R. B. Sills and M. D. Thouless Department of Mechanical Engineering Department of Materials Science & Engineering University of Michigan Ann Arbor, MI 48109-2125, USA Abstract Cohesive-zone models of fracture provide a framework that allows a smooth transition between a strength-based approach to fracture and an energy-based approac...

in this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. the model is derived from the framework of generalized biot theory. the fracture propagation is governed by a cohesive fracture model. the flow within the fracture zone is modeled by the lubrication equation. the displacement of solid phase, and...

Are the cohesive laws of interfaces sufficient for modelling fracture in polycrystals using the cohesive zone model? We examine this question by comparing a fully atomistic simulation of a silicon polycrystal to a finite element simulation with a similar overall geometry. The cohesive laws used in the finite element simulation are measured atomistically. We describe in detail how to convert the...

Cohesive zone models are explored in order to study cleavage fracture in adhesive bonded joints. A mode I cohesive model is defined which correlates the tensile traction and the displacement jump (crack faces opening) along the fracture process zone. In order to determine the traction-separation relation, the main fracture parameters, namely the cohesive strength and the fracture energy, as wel...

A mix-mode cohesive fracture model considering tension, compression and shear material behaviour is presented, which has wide applications to geotechnical problems. The model considers both elastic and inelastic displacements. Inelastic displacement comprises fracture and plastic displacements. The norm of inelastic displacement is used to control the fracture behaviour. Meantime, a failure fun...

Cohesive-zone models for interfaces incorporate both strength and energy parameters. Therefore, they provide a natural bridge between strength-based models and energy-based models for fracture, allowing delamination to be described by a single framework that covers a range of applications for which the strength or energy criteria alone might not be sufficient. In this paper, the relationships b...

OBJECTIVES To observe porcelain veneer behavior of zirconia and metal-ceramic full coverage crowns when subjected to compression testing, comparing zirconia cores to metal cores. STUDY DESIGN The porcelain fracture surfaces of 120 full coverage crowns (60 with a metal core and 60 with a zirconia core) subjected to static load (compression) testing were analyzed. Image analysis was performed u...

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...

In this work, we apply the multiscale cohesive method (Zeng and Li [2010]) to simulate fracture and crack propagations in polycrystalline solids. The multiscale cohesive method uses fundamental principles of colloidal physics and micro-mechanics homogenization techniques to link the atomistic binding potential with the mesoscale material properties of the cohesive zone, and hence the method can...