Characterisation and Modelling of Continuous-Discontinuous Sheet Moulding Compound Composites for Structural Applications

Characterisation and Modelling of Continuous-Discontinuous Sheet Moulding Compound Composites for Structural Applications

Author: Trauth, Anna

Publisher: KIT Scientific Publishing

ISBN: 9783731509509

Category: Technology & Engineering

Page: 468

View: 791

The main objective of this work is to significantly deepen the understanding of the material and the structural behaviour of continuous-discontinuous SMC composites, following a holistic approach to investigate microscopic aspects, macroscopic mechanical behaviour as well as failure evolution at the coupon, structure and component level. In addition, criteria to evaluate the effect of hybridisation are introduced and modelling approaches are presented and discussed.

Microstructure generation and micromechanical modeling of sheet molding compound composites

Microstructure generation and micromechanical modeling of sheet molding compound composites

Author: Görthofer, Johannes

Publisher: KIT Scientific Publishing

ISBN: 9783731512059

Category: Technology & Engineering

Page: 258

View: 787

Wir präsentieren einen Algorithmus zur schnellen Erzeugung von SMC Mikrostrukturen hoher Güte, durch Verwendung einer exakten Schließung und eines quasi-zufälligen Samplings. Darüber hinaus stellen wir ein modulares Framework zur Modellierung anisotroper Schädigung vor. Unser Konzept der Extraktionstensoren und Schädigungsfunktionen ermöglicht die Beschreibung komplexer Vorgänge. Darüber hinaus schlagen wir einen ganzheitlichen Multiskalenansatz zur Bestimmung anisotroper Versagenskriterien vor. - We introduce an algorithm that allows for a fast generation of SMC composite microstructures. An exact closure approximation and a quasi-random orientation sampling ensure high fidelity. Furthermore, we present a modular framework for anisotropic damage evolution. Our concept of extraction tensors and damage-hardening functions enables the description of complex damage-degradation. In addition, we propose a holistic multiscale approach for constructing anisotropic failure criteria.

Continuous–Discontinuous Fiber-Reinforced Polymers

Continuous–Discontinuous Fiber-Reinforced Polymers

Author: Thomas Böhlke

Publisher: Carl Hanser Verlag GmbH Co KG

ISBN: 9781569906934

Category: Technology & Engineering

Page: 448

View: 516

Discontinuous long fiber reinforced polymer structures with local continuous fiber reinforcements represent an important class of lightweight materials with broad design possibilities and diverse technical applications, e.g. in vehicle construction. However, in contrast to continuous fiber reinforced composites, extensively used in the aircraft industry, there is still a lack of integrated and experimentally proven concepts for manufacture, modeling, and dimensioning of combinations of discontinuously and continuously reinforced polymer structures. This is partly ascribed to the complexity of the manufacturing processes of discontinuously reinforced polymers, with heterogeneous, anisotropic, and nonlinear material and structural properties, but also to the resulting bonding problem of both material types. This book addresses these issues, including both continuous and discontinuous fiber processing strategies. Specific design strategies for advanced composite reinforcement strategies are provided, with an integrated and holistic approach taken for composites material selection, product design, and mechanical properties. Characterization, simulation, technology, design, future research, and implementation directions are also included. Especially in the field of application of three-dimensional load-bearing structures, this book provides an excellent foundation for the enhancement of scientific methods and the education of engineers who need an interdisciplinary understanding of process and material techniques, as well as simulation and product development methods.

Structure evolution in tribological interfaces studied by multilayer model alloys

Structure evolution in tribological interfaces studied by multilayer model alloys

Author: Cihan, Ebru

Publisher: KIT Scientific Publishing

ISBN: 9783731509998

Category: Technology & Engineering

Page: 194

View: 596

Recent studies of deformation mechanisms of metals and alloys pioneer the better investigation of the friction and wear behavior of materials with well-defined initial microstructures. Within this scope, in this work, the effect of sub-surface deformations on the resulting friction and wear behavior has been searched by means of a systematic experimental study on Au-Ni metallic multilayer model alloy system.

Modeling transport properties and electrochemical performance of hierarchically structured lithium-ion battery cathodes using resistor networks and mathematical half-cell models

Modeling transport properties and electrochemical performance of hierarchically structured lithium-ion battery cathodes using resistor networks and mathematical half-cell models

Author: Birkholz, Oleg

Publisher: KIT Scientific Publishing

ISBN: 9783731511724

Category: Science

Page: 246

View: 521

Hierarchically structured active materials in electrodes of lithium-ion cells are promising candidates for increasing gravimetric energy density and improving rate capability of the system. To investigate the influence of cathode structures on the performance of the whole cell, efficient tools for calculating effective transport properties of granular systems are developed and their influence on the electrochemical performance is investigated in specially adapted cell models.

Phase-field Modeling of Phase Changes and Mechanical Stresses in Electrode Particles of Secondary Batteries

Phase-field Modeling of Phase Changes and Mechanical Stresses in Electrode Particles of Secondary Batteries

Author: Zhang, Tao

Publisher: KIT Scientific Publishing

ISBN: 9783731510024

Category: Technology & Engineering

Page: 224

View: 392

Most storage materials exhibit phase changes, which cause stresses and, thus, lead to damage of the electrode particles. In this work, a phase-field model for the cathode material NaxFePO4 of Na-ion batteries is studied to understand phase changes and stress evolution. Furthermore, we study the particle size and SOC dependent miscibility gap of the nanoscale insertion materials. Finally, we introduce the nonlocal species concentration theory, and show how the nonlocality influences the results.

Consequences of hydroxyl generation by the silica/water reaction - Part II: Global and local Swelling - Part III: Damage and Young's Modulus

Consequences of hydroxyl generation by the silica/water reaction - Part II: Global and local Swelling - Part III: Damage and Young's Modulus

Author: Fett, Theo

Publisher: KIT Scientific Publishing

ISBN: 9783731511595

Category: Science

Page: 226

View: 159

Water diffusing into silica surfaces gives rise for several effects on diffusion behaviour and mechanical properties. In a preceding booklet, we focused on diffusion and fiber strengths and deformations which were obtained by water soaking under external loading. In the present booklet we deal with results and interpretations of strength increase in the absence of applied stresses.

Consequences of hydroxyl generation by the silica/water reaction - Part I: Diffusion and Swelling

Consequences of hydroxyl generation by the silica/water reaction - Part I: Diffusion and Swelling

Author: Fett, Theo

Publisher: KIT Scientific Publishing

ISBN: 9783731511489

Category: Science

Page: 226

View: 564

Water diffusing into silica surfaces gives rise for several effectson diffusion behaviour and mechanical properties. Water added to silica glass increases its specific volume so that the silica expands near the surface. Mechanical boundary conditions give rise for compressive “swelling stresses”. This fact provides a tool for the interpretation of many experimental observations from literature.

Development of NbN based Kinetic Inductance Detectors on sapphire and diamond substrates for fusion plasma polarimetric diagnostics

Development of NbN based Kinetic Inductance Detectors on sapphire and diamond substrates for fusion plasma polarimetric diagnostics

Author: Mazzocchi, Francesco

Publisher: KIT Scientific Publishing

ISBN: 9783731511816

Category: Technology & Engineering

Page: 212

View: 829

This work aimed at designing, studying and producing the first prototypes of KIDs tailored for fusion plasma polarimetric diagnostics. Diamond was considered for the first time as substrate material for low-temperature superconducting detectors given its unmatched optical, radiation hardness and thermal qualities, properties necessary for working environments potentially saturated with radiation. This work represents a first step toward the optimization and final application of this technology.

On the Electro-Chemo-Mechanical Coupling in Solid State Batteries and its Impact on Morphological Interface Stability

On the Electro-Chemo-Mechanical Coupling in Solid State Batteries and its Impact on Morphological Interface Stability

Author: Ganser, Markus

Publisher: KIT Scientific Publishing

ISBN: 9783731510475

Category: Technology & Engineering

Page: 272

View: 843

Solid state batteries with a lithium metal electrode are considered the next generation of high energy battery technology. Unfortunately, lithium metal is prone to harmful protrusion or dendrite growth which causes dangerous cell failure. Within this work the problem of protrusion growth is tackled by deriving a novel electro-chemo-mechanical theory tailored for binary solid state batteries which is then used to discuss the impact of mechanics on interface stability by numerical studies.

Discontinuous Fiber Composites

Discontinuous Fiber Composites

Author: Tim A. Osswald

Publisher: MDPI

ISBN: 9783038974918

Category: Chemistry

Page: 212

View: 441

This book is a printed edition of the Special Issue "Discontinuous Fiber Composites" that was published in J. Compos. Sci.