Fracture of materials has been regarded as the major danger to structures and is to be avoided in design, manufacture and maintenance. However, the application of classical cold drawing technique to advanced composites consisting of brittle semiconductor/glass/2D materials and ductile polymers prone to necking enables controlled fragmentation of the target component, resulting in structured patterns in micro- down to nano- scales. The controlled fragmentation can thus be taken advantage of to produce microstructures in large scale. Mechanism of controlled fragmentation and key parameters for tuning fragment size are revealed through theoretical modeling, experiment and finite element analysis. Effects of the addition of a sacrificial layer/capping layer on fragment size to improve capability of the cold drawing technique will also be discussed.
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Themes: Microstructures and Fracture in Advanced Materials
FATIGUE DAMAGE MODELLING OF ALUMINIUM ALLOY POLYCRYSTALS CONTAINING INTERMETALLIC PHASES
The objective of this work is to model fatigue damage of the aluminium alloy AA2139 at the microscopic scale. It combines an experimental campaign and numerical simulations for a complete modelling of the alloy. Special attention is given to the reproduction of the alloy grain morphology and crystallography. Moreover, intermetallic phases are preferred sites for fatigue crack initiation in this alloy. Therefore, a method for taking into account the alloy microstructural complexity including the presence of intermetallic phases is presented. Finally, a fatigue damage model using a fatigue indicator parameter (FIP) is considered for the introduction of a crack and its propagation in simulations.
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