A5040676596- Microstructure and mechanical properties
- High-Velocity Impact and Material Behavior
- Additive Manufacturing Materials and Processes
- Energetic Materials and Combustion
- Titanium Alloys Microstructure and Properties
- Microstructure and Mechanical Properties of Steels
- Fatigue and fracture mechanics
- High Temperature Alloys and Creep
- Welding Techniques and Residual Stresses
- High Entropy Alloys Studies
- Additive Manufacturing and 3D Printing Technologies
- Crystallography and molecular interactions
- High-Temperature Coating Behaviors
- Aluminum Alloy Microstructure Properties
- Metal and Thin Film Mechanics
- Intermetallics and Advanced Alloy Properties
- Thermal and Kinetic Analysis
- Advanced materials and composites
- Aluminum Alloys Composites Properties
- Metallurgy and Material Forming
- Manufacturing Process and Optimization
- Advanced Materials Characterization Techniques
- Nuclear Materials and Properties
- Combustion and Detonation Processes
- Metal Alloys Wear and Properties
University of Oxford
2019-2024
University of Bristol
2021-2024
National University of Singapore
2021
Purdue University West Lafayette
2017-2019
Paul Scherrer Institute
2015-2018
École Polytechnique Fédérale de Lausanne
2015-2017
Crystal Plasticity (CP) modeling is a powerful and well established computational materials science tool to investigate mechanical structure–property relations in crystalline materials. It has been successfully applied study diverse micromechanical phenomena ranging from strain hardening single crystals texture evolution polycrystalline aggregates. However, when considering the increasingly complex microstructural composition of modern alloys their exposure to—often harsh—environmental...
The motion of dislocations governs the plastic deformation crystalline materials, which in turn determines mechanical properties. complex thermal history, large temperature gradients and high cooling rates during process additive manufacturing (AM) can induce dislocation density unique structures material. origin these their stability loading are debated. A novel dependent continuum dynamics (CDD) model is developed, four state variables used for each slip system representing total density,...
A coupled crystal plasticity phase field damage framework has been developed and applied to modelling initiation. novel implementation of a grain misorientation angle dependent critical energy release rate used determine reduction in the local resulting from effects intergranular carbide precipitates boundary misorientation. When notched high temperature 316H austenitic stainless steel specimen, good correlation between experimental results void nucleation statistics for was obtained. This...
The response of high-energy-density materials to thermal or mechanical insults involves coupled thermal, mechanical, and chemical processes with disparate temporal spatial scales that no single model can capture. Therefore, we developed a multiscale for 1,3,5-trinitro-1,3,5-triazinane, RDX, where continuum description is informed by reactive nonreactive molecular dynamics (MD) simulations describe reactions transport. Reactive MD under homogeneous isothermal adiabatic conditions are used...
Estimating the properties of dissimilar metal welded joints made using modern high-energy beam techniques presents significant challenges due to complex nature process. These complexities arise from different thermal and mechanical materials involved. The a joint are primarily determined by element mixing final chemical composition when two metals fused together, or filler material is used. Hence, representative model capable tracking elemental distribution temperature essential for...
Defects such as cracks, pores, and particle-matrix interface debonding affect the sensitivity of energetic materials by reducing time-to-ignition threshold pressure to initiate an explosion. Frictional sliding preexisting cracks is considered be one most important causes localized heating. Therefore, understanding dynamic fracture crystalline extreme importance assess reliability safety polymer-bonded explosives. Phase field damage model simulations, based on regularization crack surface a...
The thermomechanical behavior of solids includes dissipative processes such as plastic deformation and fracture. relative importance these on the response energetic materials has been a subject study for many decades due to their significance ignition reaction. However, constitutive model simulate anisotropy crack patterns effect slip in is not yet available. Finite strain equations that couple crystal plasticity, an equation state, anisotropic phase field damage are presented. implemented...
Abstract Selective laser melting is receiving increasing interest as an additive manufacturing technique. Residual stresses induced by the large temperature gradients and inhomogeneous cooling process can favour generation of cracks. In this work, a crystal plasticity finite element model developed to simulate formation residual understand correlation between plastic deformation, grain orientation in process. The profile structure from thermal-fluid flow growth simulations are implemented...
Mechanical insult may be able to produce chemical transformations in solids when the energy is released highly localized regions. This phenomenon responsible for nucleation of hot-spots that are ignition energetic materials. The concentration at microstructural defects leads probabilistic nature ignition. effect microstructure particles, specifically influence initial crack distribution on sensitivity ignition, studied a particle embedded polymeric matrix impact velocities 100 m/s and 400...
Precursors of failure are dislocation mechanisms at the nanoscale and organization mesoscale responsible for long-range internal stresses lattice rotation. Detailed information on link between both scales is missing, computationally experimentally. Here we present a method based x-ray Laue diffraction scanning providing time sub-micron spatially resolved evolution geometrical necessary dislocations in volumes that similar to what advanced computational models can achieve. The approach used...
Calibrating and verifying crystal plasticity material models is a significant challenge, particularly for materials with number of potential slip twin systems. Here we use digital image correlation on coarse-grained $\alpha$-uranium during tensile testing in conjunction finite element simulations. This approach allows us to determine the critical resolved shear stress, hardening rate different The constitutive model based dislocation densities as state variables simulated geometry...
Abstract Metal additive manufacturing (AM) has the potential to tailor mechanical performance of materials. Due complex thermal history and unique microstructure, AM materials are reported contain distinct dislocation networks with a high density, which affect plastic deformation behavior fracture. However, it is challenging experimentally observe formation such structures. In this work, multi-scale multi-physics crystal plasticity modeling framework that integrates...
The deformation behaviour of coarse-grained α-uranium is studied using crystal plasticity finite element simulations. constitutive model includes 8 slip and 2 twin systems, based on dislocation densities as state variables. Polycrystal simulations are carried out to reproduce the manufacturing procedure: a quenching stage followed by cutting sub volume allow relaxation internal stresses. Room temperature tension compression experiments simulated for textured samples that generated this...