Ottenere i migliori risultati risparmiando tempo e costi con la simulazione: un’alleata preziosa per il progettista Webinar 24 novembre 2021

1. Modellare i materiali compositi
con la simulazione
Mara Pagani
COMSOL

2. Agenda
▪ Composite Materials overview
What is a composite material?
Composite material application
area
▪ COMSOL specialized tool for
laminates: Composite Material
Module
▪ Live Demo
▪ Q&A
▪ Further resources
▪ Contact us
Stresses in a wind turbinecomposite blade made up of thick PVC foam as a core material surroundedby
several layers of glass fiber composite on each side combinedwith an externalcarbon fibercladding

3. ▪ Composite materials are heterogeneous
materials composed of at least two
integrated components
▪ Layered composite materials are quite
common and are widely used for aircraft,
spacecraft, wind turbine, automobile,
marine, buildings, and safety equipment
use cases.
Fiber-reinforced plastics, laminated plates,
and sandwich panels are a few common
examples of layered composite materials.
▪ Composite materials are stronger and
lighter than conventional materials, which
is why they have many potential use cases
in diverse areas.
What is a Composite Material?
Layeredcomposite material

4. Composite Materials Application Areas
▪ Aircraft industry
▪ Defense industry
▪ Wind turbine industry
▪ Building and construction industry
Doors, panels, frames, bridges
▪ Chemical industry
Pressure vessels, storage tanks, piping, reactors
▪ Automobile and transportation industry
Bicycles, automobile components
▪ Marine and railway industry
Boat hulls, rail components
▪ Consumer and sports goods
Tennis racket, golf club shaft
▪ Electrical and electronics industry
Distribution pillars, link boxes
▪ Orthopedic aids
▪ Safety equipment
Carbon fiber plastic composite tailfin for a radio-controlled helicopter model

5. In quale ambito vorresti eseguire simulazioni di materiali
compositi?
1. Aerospaziale ed energia eolica
2. Automotive e trasporti
3. Beni di consumo e articoli sportivi
4. Edilizia
5. Altro
SONDAGGIO 1

6. ▪ Why use composite materials?
High strength-to-weight ratio
Material properties can be customized
High resistance to fatigue and
corrosion degradation
Improved friction and wear properties
Low thermal conductivity and low
coefficient of thermal expansion
▪ Why not replace metals then?
High cost of raw materials and fabrication
Difficulty in reuse and disposal
Difficulty in joining different components
Different types of failure modes
Anisotropic materials — difficult to
analyse
Why Use Composite Materials?
Need for numerical
simulations

9. ▪ Software for analyzing layered
composite structures
▪ Uses layered material technology
▪ Add-on to the Structural Mechanics
Module
Add-on to the MEMS Module (does not
include the Shell and Membrane interfaces)
▪ Objective is to optimize the layup and
other parameters of a laminate
Composite Materials Module
Stresses in a composite wheel rim

10. ▪ Layered shell element
Layerwise theory (mixed shape order
possible)
Equivalent single layer theory
▪ Layered material
Layered material stack, preview plots,
connection, etc.
▪ Specialized tool for postprocessing
Layered material dataset, layered
material slice plot, through thickness plot,
etc.
Composite Materials Module Overview
Stresses in a wind turbinecomposite blade made up of thick PVC foam as a core material
surroundedby several layers of glass fibercomposite on each side combinedwith an
externalcarbon fiber cladding.

11. ▪ Nonlinear material models*
Plasticity, hyperelasticity, viscoplasticity,
creep, etc.
▪ Failure analysis
First-ply failure, linear bucking,
delamination, etc.
▪ Multiscale analysis
Micromechanics
Macromechanics
▪ Multiphysics analysis
Heat transfer, electromagnetics
Acoustics, fluid flow
Composite Materials Module Overview
* Requires Nonlinear StructuralMaterialsModule
Buckling mode for the same composite laminatewith
differentchoice of fiber orietnationsin the lamina

12. ▪ Stacking sequence is the fiber
orientation in each ply with respect to
the main axis of the laminate coordinate
system
▪ Based on the stacking sequence,
laminates can be classified as:
Angle-ply
Cross-ply
Balanced
Symmetric
Antisymmetric
Stacking Sequence and Laminate Types
0°
-45°
90°
45°
0°
Stacking sequenceof an antisymmetric-balancedlaminate

13. Micromechanics: Fibre-Matrix Modelling
Representativeunit cell of a fibre composite layer having 20% fibre volume fraction
Fiber
(orthotropic properties)
Matrix
(isotropic properties)
Lamina/layer/ply
(homogenized orthotropic
properties)
Mixed in a given
volume fraction
This is achieved using
Cell Periodicity* feature
* Available in Solid Mechanics interface
Used for laminate modeling

14. Macromechanics: Laminate Modelling
Stacking
sequence
Material properties
of each layer
Thickness of
each layer
Number of
sublayers in each
layer
Surface
geometry
Laminate
coordinate system
Physical
offset
Step 1
Step 2
Stacking sequenceof a laminate Cross section of a laminate

15. Equivalent single layer (ESL) theory
▪ Computes homogenized material
properties of entire laminate and solves
only at midplane
Layerwise (LW) theory:
▪ Solves also in thickness direction and
can be used for very thick laminates
including delaminated regions
Which Laminate Theories Are Available?
Available in Layered Linear Elastic Material
node in Shell and Membrane interfaces
Available in Layered Shell interface

16. ESL theory
▪ Shell-like formulation
▪ Dof (3 displacements, 3 rotations) on the
meshed boundary
▪ Thin to moderately thick laminates
▪ Finding global response as gross
deflections, eigenfrequencies, critical
buckling load, and in-plane stresses
▪ Computationally inexpensive
▪ Shear correction factor for thicker
laminates
Layerwise theory
▪ Solid-like formulation
▪ Dof (3 displacements) distributed also in
the thickness direction
▪ Moderately thin to thick laminates
▪ Predicts interlaminar stresses and
suitable for delamination and detailed
damage analysis
▪ Supports piezoelectric material model
▪ No need of shear correction factor
ESL Theory Vs. Layerwise Theory

17. Laminate Theory Selection
Very Thick Very Thin
Laminate Aspect Ratio
Layerwise Theory
ESL Theory
h
l
Laminate Aspect Ratio = l/h

18. ▪ Laminate coordinate system and layer local
coordinate system
▪ In-plane and out-of-plane shape functions can
have different order
▪ No need to build a 3D geometry with many
thin layers
▪ In-plane finite element meshing is
independent of the out-of-plane meshing
▪ Easy to handle layerwise and interfacial data
Benefits of Layerwise Theory over 3D Elasticity
Stresses in a simply supportedthree-layercomposite laminatesubjectedto bending

19. A quale tipologia di compositi sei interessato?
1. Compositi particellari
2. Compositi rinforzati con fibre
3. Compositi strutturati (ad esempio pannelli sandwich)
SONDAGGIO 2

20. Layered Material
▪ Inputs (per layer):
Material
• Reference to an ordinary
material
Thickness
Orientation
• Relative to laminate system
Discretization in thickness
direction
▪ Input formats
Direct table input
Load from text file
Stored in material libraries
The layup of a layeredmaterial,together with a layer stack previewplot showing principal fiber orientationsof each
layer

21. Layered Shell Interface
▪ Available under Structural Mechanics in
Model Wizard
▪ Based on layerwise laminate theory
▪ Supported space dimensions:
3D
▪ Supported analysis types:
Stationary, parametric
Time dependent
Eigenfrequency, frequency domain
Linear buckling
Random vibration

22. ▪ A material model in the Shell and
Membrane interfaces
▪ Based on the equivalent single layer
laminate theory
▪ Supported space dimensions:
3D, 2D axi
▪ Supported analysis types:
Stationary, parametric
Time dependent
Eigenfrequency, frequency domain
Linear buckling (only in the Shell interface)
Random vibration, response spectrum
Layered Linear Elastic Material

23. ▪ Available in Layered Shell, Shell, and
Membrane interfaces
▪ Linear elastic material
Plasticity *
Creep *
Viscoplasticity *
▪ Hyperelastic material *
Only in Layered Shell interface
▪ Possible to have different material
models in different layers of a laminate
Nonlinear Material Models
* Requires Nonlinear StructuralMaterialsModule

24. ▪ The following failure criterion are
available in both laminate theories:
Isotropic:
• Von Mises,Tresca, Rankine, St. Venant
Orthotropic:
• Jenkins, Waddoups, Tsai–Hill, Hoffman,
Tsai–Wu
Anisotropic
• Tsai-Wu
▪ Additionally, the equivalent single layer theory
allows the following failure criteria:
Orthotropic:
• Azzi–Tasi–Hill, Norris, Modified Tsai–Hill
First-Ply Failure (Safety)
Hoffman safety factor in differentplies of a laminate

25. First-Ply Failure (Safety)
▪ Fibre-composite-specific failure criterion are available for both laminate theories:
Zinoviev
Hashin & Rotem
Hashin
Puck
LaRC03
Failuremodes in Puck criterion

26. Delamination
▪ Available in Layered Shell
interface
▪ Initial state
Bonded or delaminated
▪ Adhesive stiffness
▪ Cohesive zone models
Displacement or energy based
▪ Traction-separation law
Linear, polynomial, exponential,
etc.
▪ Contact after delamination
Progressive delamination ina laminatedshell

27. Structural Couplings and Contact
▪ Structural couplings for Layered
Shell to connect with Solid, Shell, or
Membrane elements:
Layered Shell - Structure Cladding
Layered Shell - Structure Transition
▪ Contact for Layered Shell:
Layered Shell to Layered Shell
contact
Layered Shell to Solid, Shell or
Membrane contact Model of a layeredshell connectedto solid and shell elementsin claddingand
transitionconfigurations.The results show the stress distributionin the layeredshell
(colour plot) as well as in the solid and shell members (colour wireframe plot).

28. Structural Contact
▪ Layered Shell to:
Layered Shell contact
Solid contact
Shell contact
Membrane contact
Meshed surface contact
▪ Shell/Membrane to:
Shell contact
Membrane contact
Layered Shell contact
Solid contact
Meshed surface contact
Stress distribution in different layers of a composite laminate while modeling
contact with a cylindrical surface.

29. Micromechanics (Cell Periodicity)
▪ Micromechanics analysis can be performed
using the Cell Periodicity node in the Solid
Mechanics interface
▪ Needs 3D solid geometry of a unit cell (RVE)
having fibre matrix and their material
properties
▪ Solves for six load cases
▪ Creates a node containing homogenized
material data
* Cell Periodicity is available withStructural Mechanics Module

30. LOAD CASE 1
Strain XX
Micromechanics (Cell Periodicity)
LOAD CASE 2
Strain YY
LOAD CASE 3
Strain ZZ
LOAD CASE 4
Strain XY
LOAD CASE 5
Strain YZ
LOAD CASE 6
Strain XZ

31. Multiphysics Couplings
▪ Multiphysics coupling nodes available for
Layered Shell, Shell, and Membrane interfaces:
Heat transfer
Acoustics
Fluid flow
▪ Piezoelectricity, Layered Shell interface:
Layered Shell
Electric Currents in Layered Shells
Layered Piezoelectric Effect
Example of fluid-composite interaction.Left:Velocity magnitudeof
the fluid flow. Right: Von Mises stresses in a composite plate
Thermal stress in a composite laminate

32. Quali analisi vorresti aggiungere alla modellazione di
materiali compositi?
1. Analisi micromeccanica (modellazione fibra-matrice)
2. Analisi macromeccanica (modellazione del laminato)
3. Analisi di rottura (buckling e rottura first ply)
4. Delaminazione (danneggiamento progressivo)
5. Analisi multifisica (accoppiamento termoacustico…)
SONDAGGIO 3

33. LIVE DEMO
Thermal expansion of
a laminate
▪ Thermal expansion of a laminate,
subjected to a deposited beam
power heat source, is modelled.
▪ Laminate has six layers with [30/-
45/75/-75/45/-30] stacking
sequence.
▪ Layerwise theory is used in this
model.
Normal and Shear stress
Temperaturedistributionand von Mises stress and
deformation

35. Models Are Created by
the Modeling Specialist
MODEL
Physics
Parameters
Geometry
Properties
Study
Results
Postprocessing
Reports

37. Applications Are Built by
the Modeling Specialist
Input
Output
Reports
APPLICATION

38. Q&A Session

39. ▪ Find user stories as well as tutorial blog
posts on the COMSOL Blog
▪ Examples of blog posts about
composites:
Optimizing Composite Wheel Rim
Designs with COMSOL Multiphysics®
Modeling Multi-Ply Materials with
Composite materials Technology
Introducing the Composite Materials
Module
The COMSOL Blog

40. Further Resources
to Get Started
comsol.it

41. Contact Us
comsol.it/contact