114 lines
3.8 KiB
Markdown
114 lines
3.8 KiB
Markdown
#description
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# Finite element method
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full notes : [[Finite element method]]
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### Weak Formulation
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[video](https://www.youtube.com/watch?v=xZpESocdvn4) *(30min)*
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The weak formulation is the formulation of the differential equation so that it becomes solvable using the finite elements method.
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This video shows how the weak formulation is derived from the initial problem, and its use.
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### Mathematical Finite element method base
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[video](https://www.youtube.com/watch?v=1wSE6iQiScg) *(40min)*
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The finite element method is a mathematical method to be able to computationally solve a differential equation.
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The core of the method is to discretise the problem, because computer cannot solve the problem analytically.
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# Continuum mechanics
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full notes : [[Continuum Mechanics]]
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### Continuum mechanics
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[video](https://www.youtube.com/watch?v=rhDkluTuWlQ) *(10min)*
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This video goes over what is continuum mechanics, and the uses of fields to describe matter. It presents as well the boundary value problem.
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### Strain tensor formula
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[video](https://www.youtube.com/watch?v=X-H3Fwdm-kI) *(10min)*
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The strain tensor is the symmetric part of the gradient of the displacement field vector.
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This video manages to make this confusing statement a lot clearer.
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### Visualizing the strain tensor
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[video](https://www.youtube.com/watch?v=UQ4GnWACesY) *(10min)*
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This video makes the physical effect of each element of the tensor more apparent.
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### Stress and traction
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[video](https://www.youtube.com/watch?v=NtTVEzZS3Bg) *(10min)*
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In continuum mechanics, the force over an area is not the stress, it is traction. This video helps getting a clearer understanding of the stress tensor.
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# Laminate analysis
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### Composite materials course
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[video](https://www.youtube.com/watch?v=j3rvtgqrGsQ) *(1h30)*
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This video is a course on the analysis of composite laminate. Mainly the maths to compute the stress/strain relationship with discrete layers.
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(see [[Layerwise Theories]])
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## Modeling layered composite
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[video](https://www.comsol.fr/video/modeling-layered-composite-structures-with-comsol-multiphysics-nov-29-2018) *(1h)*
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This video exposes multiple models for composite laminates, for example equivalent single layer (eql) and layerwise (lw)
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(see [[Composite laminate models]])
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# Failure theories
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full notes : [[Failure Theories]]
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### Failure theories
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[video](https://www.youtube.com/watch?v=xkbQnBAOFEg) (15min)
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This video presents a few failure theories, and their physical meaning :
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Ductile materials :
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- Tresca
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- von Mises
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Brittle materials :
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- Coulomb-Mohr
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# Polymers
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## What are elastomers ?
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[video](https://www.youtube.com/watch?v=ZUlQXcm5A4o) (3min)
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This video gives a brief overview of what are [[Elastomers]]
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Elastomers are polymers which displays [[Viscoelasticity|viscoelastic]] properties, they have a larger elastic deformation domain than other polymers, because they are lightly-cross linked.
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## Polymer course - part 1
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[video](https://youtu.be/CF6x3UVD6_I?si=OCep-ABzbdi2thwv)
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#### Homopolymers vs Copolymers
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Homopolymers are constructed with a single repeating monomer
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Copolymers are constructed with more than one monomer, can be :
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- alternating # - * - # - *
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- block # - # - # - * - * - *
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- graft (with branches)
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- random
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#### Chain structure classification
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Linear polymer chain : almost only thermoplastics
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*(slide past one another)*
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Branch polymer chain structure : usually thermoplastic, but depend on branches
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*(slide, but can catch branches)*
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Star polymer chain, all branches from one central monomer : thermoplastic/thermoset
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Polymer networks,lot of cross linking : almost only thermosets
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Interpenetrating polymer networks, that are intertwined.
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#### Thermoplastics vs Thermosets
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thermoplastic : heat -> mold -> cool -> strengthen
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(can be recycled)
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thermoset : heat -> burn
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but better hold shape and strength when heated
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(3d cross linking)
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