#description

# optimization of carbon-epoxy plates with a viscoelastic layer
*2020* #perforated #vem
[online ref](https://www.tandfonline.com/doi/abs/10.1080/15376494.2021.1882626)
[[Article_Taylor_and_Francis_vfinal.pdf|local ref]]

**basis of the work**

*both experimental and numerical analyse*

This papers explore the use of [[PCLD]], its goal is to optimise the damping (of the dynamic response) from the [[Viscoelasticity|viscoelastic]] layer (DYAD) while keeping some stiffness (at least half of the undamped plate), by studying the size and placement of the bridges between the two external layers of carbon-epoxy.

The bridges are made by puncturing the viscoelastic layer with holes so that some of the epoxy matrix fills them.

The simulations where made using the [[Finite element method]], with 2D elements for the carbon-epoxy layers and 3D elements with a [[Hyperelastic model|neo-hookean visco-hyper-elastic behavior law]] for the inserted layer. The simulations are accurate with the experiments.

The paper also points out an issue with the manufacturing of the bridges : the epoxy does not fill the holes fully, so there are bubbles or gaps, diminishing the properties of the material.


# thesis
*2020* #perforated #vem
[[manuscrit_de_these_de_Remy_Mateu_Pastor.pdf|local ref]]
Viscoelastic layer :
hyperelastic (see [[manuscrit_de_these_de_Remy_Mateu_Pastor.pdf#page=27|ref]]) when static
viscoelastic (see [[manuscrit_de_these_de_Remy_Mateu_Pastor.pdf#page=29|ref]]) when dynamic

It is possible to tweak the hyperelastic parameters with the frequency and conjugate it to a viscoelastic model.

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## Improving carbon-epoxy toughness via interleaved porous PES
*2019* #perforated
[online ref](https://www.sciencedirect.com/science/article/abs/pii/S0266353819313806)
[[Improving_carbon-epoxy_toughness_via_interleaved_porous_PES.pdf|local ref]]

This papers aims to assess the improvements of adding perforated polyethersulfone (PES) films (**viscoelastic ?**) to the interlaminar fracture of carbon-epoxy laminates.

An increase of the fracture energy for [[Fracture Toughness#Fracture modes|mode I and II]] was shown. In addition to that, an increase of the interlaminar shear strength was observed, with no significant changes in the flexural and tensile properties.

Common interleaves : microfiber veils, continuous films and electrospun nanofiber mats.