Modelling and aerodynamic simulation of a vehicle and failure

188 Pages·2005·5.66 MB·English

by  Manuel Matos

INSTITUTO SUPERIOR DE ENGENHARIA DE LISBOA

Mechanical Engineering Department

ISEL

Modelling and aerodynamic simulation of a vehicle
and failure analysis of a laminated front fender.
(Project VEECO)

VIRGÍLIO OLIVEIRA DOMINGUES SESTA

(Bachelor degree in Mechanical Engineering)

Master Thesis in mechanical engineering field of maintenance and production

Supervision:
Ph.D. Maria Amélia Ramos Loja

Co-Supervision:
MSc Afonso Manuel de Sousa Leite
Jury:
President:
Ph.D. João Carlos Quaresma Dias

Vogues:
Ph.D. Jorge Manuel Fernandes Trindade
Ph.D.Victor Manuel dos Reis Franco Correia
Ph.D. Maria Amélia Ramos Loja
MSc Afonso Manuel daCosta Leite

April 2014
INSTITUTO SUPERIOR DE ENGENHARIA DE LISBOA

Mechanical Engineering Department

ISEL

Modelling and aerodynamic simulation of a vehicle
and failure analysis of a laminated front fender.
(Project VEECO)

VIRGÍLIO OLIVEIRA DOMINGUES SESTA

(Bachelor degree in Mechanical Engineering)

Master Thesis in mechanical engineering field of maintenance and production

Supervision:
Ph.D. Maria Amélia Ramos Loja

Co-Supervision:
MSc Afonso Manuel de Sousa Leite
Jury:
President:
Ph.D. João Carlos Quaresma Dias

Vogues:
Ph.D. Jorge Manuel Fernandes Trindade
Ph.D. Victor Manuel dos Reis Franco Correia
Ph.D. Maria Amélia Ramos Loja
MSc Afonso Manuel da Costa Leite

April 2014
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ACKNOWLEDGMENTS
The development of this master thesis was only possible with the collaboration
of some people and entities. The author would like to thank the time and attention
provided by the supervisor, Professor Maria Amélia Ramos Loja, that helped overcome
the issues encountered during the work, and was always available to help improving the
final result whether with suggestions or advices.
Special thanks to engineers Paulo Almeida, and Celso Menaia, for their time and
availability to help during the course of this work, not only with issues directly related
to the project but also providing all the help in every occasion.
A deeply thank for all the love, support, opportunities and education provided by
my parents, specially my mother who gave me a wonderful education, and helped in
many occasions. When no one else believed in my success she was the one to encourage
me to go on.
All the encouraging words and support received from all the friends and
colleagues that helped the author keep on the work. And a special thanks to my
girlfriend Marisa for the comprehension and love.
Finally to V.E. – Fabricação de veículos de tracção eléctrica, and the CEO, Mr.
João Oliveira, by the leadership in the Project VEECO (Ecologic electric vehicle), the
will to make the project happen and also the time and patience to endure through the
entire process, and to all the personal in the CIPROMEC, particularly Mr. Carlos Lucas,
for the time and patience to help, and the enthusiasm shown for the work developed.

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ABSTRACT
The main goals of this project were the development of the body for an electric
vehicle and the study of the front fender.
Various aspects related with the project of a fiberglass component were
addressed in this work like the choice of materials, and manufacturing processes of
composite materials.
The model was entirelly designed using the software CATIA V5 and based in
that model the aerodynamic studie was conducted using the software ANSYS 11.
This study used Computacional Fluid Dynamics code, ANSYS-CFX to predict
the static aerodynamic characteristics of the vehicle VEECO. The study was conducted
for several wind speeds. The results were compared against experimental data from
actual wind tunnel tests.
In order to test the front fender, this was modeled seperatly and imported to
ANSYS classic. A model with solid elements and a tailored mesh was developed,
having one element per ply in the through the thickness direction and accounting for
aspects like contact and laminate layup. Failure analysis was made by a progressive
damage model with a set of Hashin type failure criteria.

Keywords:
Design with CATIA V5, ANSYS workbench and ANSYS classic, Aerodynamic study,
Stress analysis

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RESUMO
Os principais objectivos deste trabalho foram o desenvolvimento da carroceria
para um veículo eléctrico, e o estudo do pára-choques dianteiro.
Foi também necessário estudar processos de fabrico adequados para a situação e
para o tipo de produção desejado, bem como a seleção de materiais.
O modelo foi todo desenhado utilizando o software CATIA V5, e baseado neste
modelo foi feito o ensaio aerodinamico recorrendo ao software ANSYS 11.
O estudo teve por base o código de CFD do ANSYS e serviu para determinar as
caracteristicas aerodinamicas do VEECO. Este estudo foi feito com diferentes
velocidades e os resultados foram depois comparados com os valores obtidos do ensaio
em tunel de vento real.
De modo a testar o para-choques, este foi modelado separadamente e importado
para ANSYS classic, onde foi criado um modelo de elementos finitos e a respectiva
malha. O modelo desenvolvido contava com um elemento por camada na direção da
espessura e teve em conta aspectos como o contacto interlaminar e a direção de
laminação. A analise de falha foi baseada num modelo com o criterio de Hashin como
critério de falha.

Palavras chave:
Modelação em CATIA V5, Ensaios em ANSYS workbench e ANSYS classic, Estudos
aerodinâmicos, análise de elementos finitos.

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LIST OF SYMBOLS

γ Engineering shear strain associated to plane ij (i≠j)
ij
ε Normal strain along direction i
ii
ε Shear strain associated to plane ij (i≠j)
ij
θ Angle between the laminate axis (x) and fibre direction (1)
μ Coefficient of viscosity
ρ Fluid density
σ Normal stress along direction i
ii
σ Shear stress on ij plane (i≠j)
ij
τ Surface shear force
υ Poisson‟s ratio
ij
δ Displacements
0,0
x y Mid-plane extensional strains along x and y directions
k0,k0,k0
x y xy Mid-plane curvatures
[A] Laminate membrane stiffness matrix
[B] Laminate membrane-bending coupling stiffness matrix
[D] Laminate bending stiffness matrix
F ,F 
G L Forces vectors
[J] Jacobian matrix
[K] Stiffness matrix
[S] Compliance matrix
Q
  Transformed reduced stiffness matrix
[T] Reduced transformation matrix
2D Two dimensional
3D Three dimensional

A Area
C C C
, , Friction, drag and lift coefficients
f D L
E, E Fibre and matrix Young‟s modulus
f m
E Elasticity modulus along direction i
i
G Shear modulus associated to plane ij
ij
H Total laminate thickness
h Thickness of kth layer
k

L Length
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