Mechanical Behaviour ofMechanical Behaviour of Highly ... Mechanical Behaviour ofMechanical...
Embed Size (px)
Transcript of Mechanical Behaviour ofMechanical Behaviour of Highly ... Mechanical Behaviour ofMechanical...
Mechanical Behaviour ofMechanical Behaviour of Highly Packed Particulate Composites
Henry Tany School of Engineering, University of Aberdeen, UK
Highly Packed Particulate Composites (HPPCs)
Five topics on the “Mechanical Behaviour of “Highly Packed Particulate Composites” (HPPCs)
1. Microstructure of Highly Packed Particulate CompositesComposites
2. Interface Cohesive Law 3. Network Formation and Percolation Modelling3. Network Formation and Percolation Modelling 4. Materials Point Method and X‐Ray tomography 5. Catastrophic Behaviours under Loading5. Catastrophic Behaviours under Loading
Mechanical Behaviour of Highly Packed particulate Composites (HPPCs)g y ac ed pa t cu ate Co pos tes ( Cs)
1 Microstructure of HPPCs1. Microstructure of HPPCs
One of the greatest challenges in the food industries is to develop products that can fracture in a pre‐designed way so that they can provide the required function.
Sedimentary rocks are made of sediments cemented or compacted together by a particular force or process over time.
P ti l i 50
Mudstone, 泥岩 Conglomerate , 砾岩 Sandstone, 砂岩
S di t k l t th ti fl d
Particle size 2mm Particle size
bamboo poplar eucalypt pine
Cellular Structure of Wood
bamboo poplar eucalypt pine
Mayo, Evans, Chen, Lagerstrom, 2009, Journal of Physics
Brick‐and‐mortar like network.
Li X, Huang Z (2009) Unveiling the Formation
Mechanism of Pseudo‐Single‐Crystal Aragonite Platelets in Nacre, Phys Rev Lett.
Hierarchical Organization in Nacre
crystal / biological binderBrick‐mortar network biological binderBrick mortar network
Luz and Mano , 2009
Plastic Bonded Energetic Materialg
coarse particlesp (~250 m)
fine particles (~8m)
High volume fraction ~93%g
High specific surface of interface
Bimodal Size Distribution
Safety in Nuclear Decommissioning
Partnership with Sellafield Ltd Decommissioning, Cumbria, 2007 -p g, ,
Explosive charges placed under the cooling towers of Calder Hall Plant
Controlled collapse of each tower. (World Nuclear News)cooling towers of Calder Hall Plant.
A d t di f th iti it f l i t f d t l
(World Nuclear News)
An understanding of the sensitivity of explosives at a fundamental level is important for safety in nuclear decommissioning.
Solid Propellant Rocket
DDT: normal surface burning ‐>explosion
Catastrophic interface debonding ‐> formation of hotspot
Microstructure of solid propellant material. Id l 1999
Center for Simulation of Advanced Rockets, UIUC
Ide et al., 1999 • Ignition and combustion of composite energetic materials • Solid mechanics of propellant, case, insulation, and nozzle • Fluid dynamics of interior flow and exhaust plume
Pressure – Burn – Microstructure
Relatively small defects, like debonded interfaces and cracks, can lead to catastrophic failure.
Several typical Highly Packed Particulate Composites (HPPCs)