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--- team:gdeliege:composite [2015/08/13 17:12] – geoffrey
+++ team:gdeliege:composite [2016/03/30 15:23] (current) – external edit 127.0.0.1
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 ===== Composite materials =====
+=== Background ===
 Carbon-Fibre-Reinforced Polymers (CFRP) are now widely used in aerospace industry
@@ Line 8: / Line 10: @@
 (fibre brittle failure, fibre-matrix debonding, matrix ductile failure and delamination)
 that are not easily described at a macroscopic level.
+When I joined the MN2L-group, my first objective was to implement a material model for composite laminates with woven fibre reinforcement in Metafor. This was part of a project in collaboration with Sonaca, LMS-Samtech and the Université Catholique de Louvain, among others.
-My objective was to implement a material model for composite plies with woven fibre
+=== Constitutive laws ===
-reinforcement in Metafor.
-This model is inspired by the meso-model
+This model I implemented is inspired by the meso-model
 proposed by P. Ladevèze and O. Allix [1-2] for unidirectional
 composites as well as the 2D model for woven composites proposed by C. Hochard [3].
 The idea is to describe the laminate as a stack of 3D orthotropic plies separated by 2D interfaces.
-In a direction parallel to the fibres,
+In directions parallel to the fibres,
 the plies are elastic and subject to brittle fracture;
-in shear, an elastoplastic behaviour is assumed and progressive damage is introduced.
+in shear, an elastoplastic behaviour with progressive damage is assumed.
 The 2D interfaces between the plies are elastic with progressive damage.
 Practical information on the
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 One interesting feature of Ladevèze and Allix's work is that most parameters of the constitutive laws
 can be linked to physical quantities.
-Therefore, these parameters can be identified with suitable experimental tests.
+Therefore, these parameters can be identified with suitable experimental tests. For example, the hardening and damage parameters characterizing the shear behaviour are determined by cyclic loading tests on a  $[(+45^\circ/-45^\circ)_n]_S$  laminate (Fig. 1).
+Complex as they are, these models neglect important phenomena like the viscoplastic behaviour of the resin or the specific damage mechanism under compressive loading. I am currently working on compressive damage of woven fibre laminates. My goal is to introduce in the mesoscopic model a damage evolution law accounting for the microscopic instabilites (microbuckling) generated in a ply under compression.
 {{ :team:gdeliege:comp05.png?500 |}}
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 {{ :team:gdeliege:comp04.png |}}
-//Figure 4. Impact simulation : (left) experimental setup for impact testing at [[http://www.uclouvain.be/en-imap.html|UCL-IMAP lab. (Prof. Pardoen)]], (right) finite element model of the impact test; the impactor is represented as a rigid sphere having the same mass and kinetic energy as the experimental impactor.//
+//Figure 4. Impact simulation : (left) experimental setup for impact testing at [[http://www.uclouvain.be/en-imap.html|UCL-IMAP (Prof. Pardoen)]], (right) finite element model of the impact test; the impactor is represented as a rigid sphere having the same mass and kinetic energy as the experimental impactor.//
 {{ :team:gdeliege:comp03.png |}}