Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 28 for “"dynamic fracture"”.
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The static and dynamic fracture of brittle materials
… the initial period of loading, at the onset of fracture and during the stage of rapid crack propagation, have been performed in order to gain an insight into some of the fundamental processes of brittle fracture which might prove useful in the solution of practical problems in mining and process …
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Modelling of dynamic fracture by Phase Field and Finite Fracture Mechanics
L'abstract è presente nell'allegato / the abstract is in the attachment
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Cohesive Modeling of Dynamic Fracture: Rate Dependence and Intersonic Crack Motion
The second dynamic fracture problem addressed in this thesis is concerned with the issue of intersonic crack propagation, a topic of great interest in the fracture mechanics and geophysics community with the recent first direct observations of shear cracks exceeding the shear wave speed in …
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Dynamic Fracture of Adhesively Bonded Composite Structures Using Cohesive Zone Models
Using experimental data obtained from standard fracture test configurations, theoretical and numerical tools are developed to mathematically describe non-self-similar progression of cracks without specifying an initial crack. A cohesive-decohesive zone model, similar to the cohesive zone model …
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Extrinsic Cohesive Modeling of Dynamic Fracture and Microbranching Instability Using a Topological Data Structure
Realistic numerical analysis of dynamic failure process has long been a challenge in the field of computational mechanics. The challenge consists of two aspects: a realistic representation of fracture criteria, and its efficient incorporation into a viable numerical scheme. This study investigates …
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Multi-paradigm modeling of mode I&II dynamic fracture mechanisms in single crystal silicon
… and similar technologies. The understanding of fracture of silicon is crucial for the engineering process and the development of robust devices. However, the mechanisms of fracture in silicon are complex and are still not fully understood. Several experimental studies of fracture have been …
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A scalable computational approach for modeling dynamic fracture of brittle solids in three dimensions
… method is proposed for modeling threedimensional dynamic fracture of brittle solids. The method is based on a combination of the discontinuous Galerkin (DG) formulation of the continuum elastodynamic problem with Cohesive Zone Models (CZM) of fracture. In the proposed framework, discontinuous …
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Next generation computational tools for extreme-scale simulation of dynamic fracture and fragmentation in three dimensions
The accurate modeling of dynamic fracture and fragmentation remains one of the most difficult challenges in computational mechanics research. As part of this thesis, a scalable algorithm for modeling dynamic fracture and fragmentation of solids in three dimensions is developed. The method is based …
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Applications of the Optical Method of Caustics to the Study of Viscoelastic Dynamic Fracture and Static Blunt Crack Fronts
The opto-mechanical relation, as used in the optical methods of photoelasticity and caustics, are extended to linearly viscoelastic materials. The Maxwell-Neumann relation for the stress-optic constants, which is good for linearly elastic behavior, is replaced by an expression derived from the …
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A Mixed Eulerian-Lagrangian Model for the Analysis of Dynamic Fracture (Finite Element Method, Moving Mesh, Virtual Energy Release Rate)
… formulations for the analysis of static and dynamic brittle fracture problems based on a mixed Eulerian-Lagrangian kinematic model. Effective finite element computational methods based on the continuum formulations are also described.
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Grain-Level Simulation of Dynamic Failure in Ceramic Materials
… the grain-based CVFE code, we investigate four dynamic fracture problems. The first one is concerned with the propagation of dynamic intergranular cracks under mode I loading, with special emphasis on the effect of the microstructure on the branching instability of the crack motion. The second …
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Study of layer orientation on the fracture behavior of two additively manufactured thermoset resins, A
This work examines the fracture behavior of additively manufactured (AM) thermosetting resins to enable rapid production of lightweight and functional polymeric and composite materials that can meet a wide range of applications. Specifically, the role of print orientation on the quasi-static and …
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Some Aspects of the Mechanics and Mechanisms of Dynamic Brittle Fracture
Previous research in dynamic fracture mechanics has focused largely on steady-state growth in the absence of reflected stress waves. This is because of the analytical and experimental complexities of studying crack propagation in finite geometries. For example, inadequate spatial and temporal …
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Potential-Based Fracture Mechanics Using Cohesive Zone and Virtual Internal Bond Modeling
… of nonlinear constitutive relationships along fracture surfaces is a fundamental issue in mixed-mode cohesive fracture simulations. A generalized potential-based constitutive theory of mixed-mode fracture is proposed in conjunction with physical quantities such as fracture energy, cohesive …
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Applications of Continuous Wavelet Transform in Hydraulic Fracturing and Reservoir Management
… of Continuous Wavelet Transform (CWT) in fracture diagnostics and reservoir management, offering an in-depth analysis of various methods and their effectiveness. It addresses key aspects of hydraulic fracturing diagnostics, including fracture closure identification, dynamic fracture event …
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A comparative study of shared memory parallelism on regular and irregular data structures using OpenMP and Galois
… High Accuracy Relativistic Magnetohydrodynamics (HARM) which operates on a grid data structure; Delaunay Triangulation, which refines a triangulated mesh; and Dynamic Fracture Propagation, which operates on a triangulated mesh with adaptive refinement; is evaluated. It is found that …
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Failure processes in unidirectional composite materials
… first time. Further, the results indicate that dynamic fracture participates to a significant extent in determining the failure process in these materials. Based on the results of this study the influence of various parameters in determining the composite strength is described.
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Time- and Temperature-Dependence of Fracture Energies Attributed to Copper/Epoxy Bonds
… forces, the need arises to characterize fracture energies corresponding to related, high-speed failure events. Work (or energy) is required to create new surface area—with associated dissipation events—during fracture, and this energy (for a given material system) is dependent on the …
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The effects of microstructure and nanostructure upon dynamic ductile fracture
Dynamic fracture is an important process in the behaviour of materials. However, the effects of material microstructure on dynamic fracture processes are not well understood. This thesis investigates the role of material microstructure and nanostructure in dynamic ductile fracture, such that the …
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Numerical Methods for Fluid-Solid Coupled Simulations: Robin Interface Conditions and Shock-Dominated Applications
… algorithms for coupling computational fluid dynamics (CFD) and computational solid dynamics (CSD) solvers, and the use of these solvers for simulating fluid-solid interaction (FSI) problems involving large deformation, shock waves, and multiphase flow. The dissertation consists of two parts. …
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