Transcript 1st_Progress_Report_Presentation_101711.ppt

Layered Fiberglass vs. Injection Molded
Fiberglass Surfboard Fin Finite Element Analysis
1st Progress Report
Dan Ippolito
Project Advisor: Ernesto Gutierrez-Miravete
Rensselaer Polytechnic Institute
October 17, 2011
Layered Fiberglass vs. Injection Molded Fiberglass Surfboard Fins
Deflection Comparison Analysis
 A deflection comparison analysis is a study of two or more components in which
displacements, as a result of an applied load, are compared
 When identical loads and boundary conditions are applied, a comparison of flex
patterns can be done by observing the x, y and z displacements throughout the
geometry of the components
 To do a detailed deflection comparison finite element analysis should be uses to plot
displacement contours to visualize various deflections
 The goal of this analysis is to investigate how different the flex patterns are when a
surfboard fin is constructed of layered fiberglass vs. cheaper injection molded
fiberglass
The Project
 Model a surfboard fin as accurately as possible in Abaqus CAE
 Make two identically shaped, and meshed, fins and assign one isotropic material
properties and the other layered orthotropic material properties with alternating fiber
angles
 Apply a force to the fins exposed surface and secure the base of the fin plugs
 Run an Abaqus FEA analysis and compare deflections throughout the fin for layered
fiberglass vs. the injection molded construction
Injection Molded Fiberglass Fin
Layered Fiberglass Fin
Fin Geometry and Model Development
 To make the fin’s part geometry a popular thruster center fin (a FCS® model G-AM) is modeled as a
solid part in Abaqus CAE. This is done using a picture of the fin as well as the actual fin to scale
the part accordingly
 Since layered fiberglass must be assigned Lamina material properties, and are not suitable for solid
parts, a shell made is made using the solid fin model
 The shell is assigned various thicknesses to map the thickness contour of the solid fin. This shell
model will be used for both the isotropic injection molded fin and the orthotropic layered fiberglass
fin to provide an accurate apples to apples comparison
Picture of the FCS® G-AM
Center Fin
Abaqus Solid Model of the
FCS® G-AM Center Fin
Abaqus Shell Model of the
FCS® G-AM Center Fin
Abaqus Shell Model of the
FCS® G-AM Center Fin with
Thickness Contour Shown
Assigning Material Properties
 Assigning different materials properties to each of the two fins simulates the different construction
methods
 One fin is assigned isotropic elastic material properties, for injection molded fiberglass, and different
shell thicknesses to different geometric regions to provide the thickness contour
 The other fin will be constructed using a composite layup in which elastic orthotropic fiberglass
material properties are defined. A composite layup is assigned with defined thicknesses and
alternating fiber angles of +45°/-45°
Abaqus Shell Model of the FCS® G-AM Center Fin
Material
E1
(10^6 psi)
E2
(10^6 psi)
v12
v23
G12
(10^6 psi)
G13
(10^6 psi)
G23
(10^6 psi)
Material
E
(10^6 psi)
v
E-glass
Fiberglass
8.34
2.727
0.25
0.29
1.08
1.08
1.05
Random Short Fiber
Fiberglass/Epoxy
5.5
0.33
Material Properties for Orthotropic
E-Glass/Vinylester Fiberglass
Material Properties for Isotropic
Injection Molded Fiberglass
Calculation of Drag Force for a Full Speed Bottom Turn
 The drag force is calculated for a full speed bottom turn on a wave that is 10 ft high assuming you
are traveling the same speed as a vertical drop from that height
Derivation of Drag Pressure Applied
to Fin Exposed Surface
A Surfing Bottom Turn
Drag Force Equation
Expected Outcomes
 It is expected that layered fiberglass will behave differently that injection fiberglass when loaded.
How different these flex patterns are is what this study is aimed to find
 In general, a fin with a stiff base and flexible tip is ideal for performance
Preliminary Results of Isotropic Injection Molded Fin
References
[1] Ronald F. Gibson “Principles of Composite Material Mechanics”, second edition, CRC Press Taylor &
Francis Group, 2007
[2] White, Frank M., “Viscous Fluid Flow”, 3rd Edition, McGraw Hill, 2006
[3] Chou Shih-Pin, “Finite Element Application for Strength Analysis of Scarf-Patch-Repaired Composite
Laminates”, Master of Science Thesis, Wichita State University, Dec. 2006
[4] Stephen Pirsch, “How to Build Your First Surfboard – Glassing”, www.surfersteve.com, 2003
[5] M. Nurhaniza, M.K.A. Ariffin, Aidy Ali, F. Mustapha and A. W. Noraini, “Finite Element Analysis of
Composites Materials for Aerospace Applications”, Nov 2010
[6] Y.W. Kwon, D.H Allen, R. Talreja, “Multiscale Modeling and Simulation of Composite Materials and
Structure”, 2008