structeam and ruster sports optimisation of the new dimond
TRANSCRIPT
S T R U C Te a m a n d R u s t e r S p o r t s O p t i m i s a t i o n o f t h e
N e w D i m o n d B i k e F r a m e
Frederic Louarn
Principal engineer
STRUCTeam Ltd
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STRUC Team Introduct ion
19/07/2018 Slide: 2
Independent Composites Solution Provider
We help our clients to:
¤ Make better decisions
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¤ Select and develop appropriate technologies for their composite
business
Over 200 successful projects across all markets sectors
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D i m o n d b i ke p ro j e c t I n t ro d u c t i o n
10/23/2018Slide: 3
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This project was carried out for Ruster
Sport’s new Dimond triathlon bike design - https://www.dimondbikes.com -
with a twofold objective.
STL to provide Ruster Sport with
an understanding of complex load
paths within the critical chainstay
crotch area and to make basic
recommendations in terms of
reinforcement
STL to validate the final
laminate specification by
using appropriate safety
margins for composite
structures.
S t r u c t u ra l D e s i g n Wo r k f l o w
10/23/2018Slide: 4
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STRUCTeam's approach consisted of
developing design load cases to be
implemented in a global beam finite
element model of the bike.
Chainstay loads were extracted from
this global model and applied to a local
shell finite element sub-model of the
frame chainstay, enabling detailed
analysis of load paths as well as
strength analysis within the critical
crotch area.
Composide FESpace
Ansys ACP
Recommendations vs
reinforcement weight
and fibre orientations
Strength
validation
Ruster Sports provided
design inputs in terms
of frame geometry and
initial laminates
Manufacturing
loop
G l o b a l B i ke F E A
10/23/2018Slide: 6
Beam Finite Element Model developed in CompoSIDE FESpace
Envelope static load cases based on EN standards and published data:
1. EN 14781 (Race bikes)
2. EN 14766 (Mountain bikes),
3. Development of experimental methods for fatigue testing of composite racing bicycle frames, S.
Styns, MSc Thesis,
4. Bicycle Frame Optimization by Means of an advanced Gradient method Algorithm, L. Maestreli,
A. Falsini.
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G l o b a l B i ke F E A
7
Loads and boundary conditions for static load case example
Ux=Uy=Uz=0
@ contact
between aft tire
and road
Ux=Uy=0
@ front dropouts
Pedal force
Fy=-1.19 kN
Fx= -0.16 kN
chain force
reaction @
cog
Handle bar
forces
chain force
Fz=2.7 kN
Fy=-0.13 kN
G l o b a l B i ke F E A
8
Predicted displacements for static load case example
Frame response dominated by
transverse bending in way of
chainstay
Chainstay crotch critical
loads components:
- axial force on chain
side
- transverse BM
Reactions Rx, Ry, Rz used
as inputs for shell FEA
10/23/2018Slide: 9
Local shell finite element model of the frame
chainstay
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L o c a l C h a i n s t ay F E A
10/23/2018Slide: 10
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Finite Element Mesh
16692 1st order laminated shell elements
“shell 181”
Refined mesh: 0.3-
0.5mm edge sizing
beam elements
around bottom
bracket penetrations
(steel ring)
Accurate geometrical
features in way of crotch
area
L o c a l C h a i n s t ay F E A
10/23/2018Slide: 11
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Laminates are simplified initially in terms of
fibre orientation and thickness VS accurate
final laminate thicknesses and fibre directions
used for validation
Contour plot of final Laminate thicknesses in ANSYS ACP
L o c a l C h a i n s t ay F E A
10/23/2018Slide: 12
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Loads and boundary conditions example
Ux=Ux=Uz=0 around downtube perimeter
Rx, Ry and Rz from framework model
L o c a l C h a i n s t ay F E A
10/23/2018Slide: 13
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Understanding load paths to make recommendations vs laminate fibre directions
L o c a l C h a i n s t ay F E A
10/23/2018Slide: 14
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Principal strain predictions to make recommendations vs reinforcement weights
L o c a l C h a i n s t ay F E A
10/23/2018Slide: 15
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Predicting strains and strength minimum reserve factors (“RF”) for final validation (after manufacturing loop)…vs ultimate static strength…and vs fatigue limit state.
C o n c l u s i o n s
10/23/2018Slide: 17
This presentation is intended to illustrate how
structural design inputs from STRUCTeam Ltd
have helped Ruster Sports to deliver the Dimond
bike frame.
Whereas the focus herewith has been on
structural design aspects, the importance of the
collaboration between the two parties has also
been highlighted as being key to a successful
project:
➢ from manufacturing inputs,
➢ to prototyping and testing,
➢ Leading to series production
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"Collaborating with Structeam on this project was a huge success for us. Their
analysis gave us a huge leg up in the development process. Using their work to
guide our initial layup design, and then being able to validate that and get
feedback from them has resulted in a great product. The resulting part has
seen zero issues, with 100s of frames in the field for 2 years and hundreds of
thousands of miles of use."
Matt Cymanski
Chief Engineer
Rüster Sports | Dimond Bikes
Thank you for your attention
Frederic Louarn
STRUCTeam
www.structeam-ltd.com
+44 (0)1983 240534
© Copyright STRUCTeam Ltd Slide: 18