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Institute for Carbon Composites donated by
Interaction of braiding ring geometry and fiber lay-up in
the braiding process
Christoph Ebel, Thorsten Hans
„A Comprehensive Approach to Carbon Composites Technology“
Symposium on the occasion of the 5 th anniversary of the Institute for Carbon Composites
Research Campus Garching, September 11th - 12th 2014
2
Summary and Outlook5
Experiments and results4
Experimental design3
Virtual preliminary investigations2
The braiding process and fiber angle deviations1
Agenda
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
3
The braiding process and fiber angle deviations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Braiding machine working principle and function of the braiding ring
4
The braiding process and fiber angle deviations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Desired braiding yarn angle
Way of mandrel:
2*Δs
Rotation:
180°
Way of mandrel:
4*Δs
Rotation:
180°
φ = 45°
2*Δs
φ = 30°
4*Δs
5
The braiding process and fiber angle deviations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Global fiber angle: Idealized yarn path for different mandrel cross-sections
Circle Square Rectangle
Way of mandrel:
4*Δs
Rotation:
360°
6
Typical yarn path on plane side
of a mandrel
Small braiding angle around edges
Great braiding angle in the center
S-shaped path of the yarn
Yarn path on plane side of a mandrel with squared cross-section
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
The braiding process and fiber angle deviationsLocal fiber angle: Overbraiding mandrels with prismatic cross-sections
7
The braiding process and fiber angle deviations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Realistic yarn path on a mandrel with rectangular cross-section (exaggerated)
Minimize deviations by appropriate shape of braiding ring?
Theoretical global fiber angle
Close to realistic yarn path
(fiber angle deviations exaggerated)
Desired angle
8
Mandrel
Squared
Rectangular, side length ratio 1:5
Braiding ring shapes
round (reference) oval elliptical
Different aspect ratios
Different orientations
Virtual preliminary investigations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
𝑙2 𝑙 1
Parameters
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round (reference) oval, oval, ratio 1:1.6 oval, ratio 1:3.5
parallel orientation normal orientation normal orientation
Virtual preliminary investigations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Different aspect ratios and orientation
65°
45°
25°
[unpublished LCC term project: 2014, Christopher Detmar, „Analyse des S-Schlag-Phänomens im Flechtprozess mittels FE-Vergleichsrechnungen“]
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1:1.5 1:1.7 1:2
Virtual preliminary investigations
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Different aspect ratios and orientation
65°
45°
25°
[unpublished LCC term project: 2014, Christopher Detmar, „Analyse des S-Schlag-Phänomens im Flechtprozess mittels FE-Vergleichsrechnungen“]
11
a/b=3
Mandrel cross-sections (U ~ const. ~ 540mm)
Circular
Squared
Rectangular
Braiding machine setup (max. diameter):
biaxial braid, 4x4 braid architecture
128 bobbins with 50k carbon fibers
Experimental Design
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Geometrical design of tested components and braiding machine parameters
a/b=2
b = 250mm
a/b=1
b=135mm
D=173mm
48mm x 226mm
Braiding ring shapes
a/b=1,5
D = 250mma1 = 375mma2 = 500mma3 = 750mm
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Experimental Design
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Integration of the test setup at the braiding machine
750mm wide elliptical braiding ring mounted at the LCC braiding machine
13
Experiments and Results
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Fiber angle measurement (2 mandrels for each configuration)
Braid formation areaEdge effects
Measuring area
Overbraided rectangular test mandrel
Size of measuring window
8 measurements around circumference 3 measurements on each side 5 and 1 measurements on respective sides
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Data acquisition via Profactor ® optical device
Fiber angle determination within defined area
Sum of values for each pixel (Profactor ®)
Edge detection (LCC-MatLab tool)
Experiments and Results
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Data acquisition and analysis
Measuring directionExample of Profactor ® stitched pictures of fiber angles on a rectangular mandrel
top
rightleft
bottom
[unpublished diploma thesis: 2014, Georg Kirmair, „Untersuchung zum Einfluss der Flechtringgeometrie auf die Faserablage beim Umflechten von Kernen“]
15
Experiments and Results
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Rectangular mandrel, braiding angle 45°, parallel orientation
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
Bra
idin
g a
ng
le [
°]
250
375
500
750
Massive angle differences
on neighboring sides
Round ring: 42° - 52°
Elliptical ring: 34° - 57°
[Test data from unpublished diploma thesis: 2014, Georg Kirmair, „Untersuchung zum Einfluss der Flechtringgeometrie auf die Faserablage beim Umflechten von Kernen“]
16
Experiments and Results
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Rectangular mandrel, braiding angle 45°, normal orientation
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
Bra
idin
g a
ng
le [
°]
250
375
500
750
Angle differences on
neighboring sides reduced
Round ring: 41° - 52°
Elliptical ring: 44° - 50°
[Test data from unpublished diploma thesis: 2014, Georg Kirmair, „Untersuchung zum Einfluss der Flechtringgeometrie auf die Faserablage beim Umflechten von Kernen“]
17
Experiments and Results
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Squared mandrel, braiding angle 45°
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
Bra
idin
g A
ng
le [
°]
250
375
500
750
Local angle deviations on left/right side reduced
Massive differences of global angle on neighboring sides
[Test data from unpublished diploma thesis: 2014, Georg Kirmair, „Untersuchung zum Einfluss der Flechtringgeometrie auf die Faserablage beim Umflechten von Kernen“]
18
Influence of ring shape decreases with
increasing global fiber angle
Very irregular braid for small angles
Experiments and Results
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
Influence of desired global braiding angle
3035404550556065707580
top
left 1
left 2
left 3
left 4
left 5
bo
ttom
rig
ht 1
rig
ht 2
rig
ht 3
rig
ht 4
rig
ht 5
Bra
idin
g a
ng
le [
°]
Global angle 60°
250
375
500
25
30
35
40
45
50
top
left 1
left 2
left 3
left 4
left 5
bo
ttom
right 1
rig
ht 2
rig
ht 3
rig
ht 4
rig
ht 5
Bra
idin
g a
ng
le [
°]
Global angle 30°
250
375
500
[Test data from unpublished diploma thesis: 2014, Georg Kirmair, „Untersuchung zum Einfluss der Flechtringgeometrie auf die Faserablage beim Umflechten von Kernen“]
19
Control of fiber angle formation by braiding ring shape
Local fiber angle deviations (s-shaped yarn path)
Reduction possible
No complete compensation with investigated braiding rings (too big)
Global fiber angles
Fiber angle differences on neighboring mandrel sides of up to 30°
Tailor profiles for specific load cases
Outlook
Investigate additional ring geometries
Understand interacting effects
Off-centric mandrel path
Guiding mandrel under an angle
Combine findings in an
„active braiding ring“
Summary and Outlook
09/12/2014 | Ebel | Interaction of braiding ring geometry and fiber lay-up in the braiding process
[http://blog.mercedes-benz-passion.com]
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Technische Universität München
Institute for Carbon Composites
Boltzmannstraße 15
85748 Garching
www.lcc.mw.tum.de
Contact
Address
Fax
Tel
Room
+49 89 /
+49 89 /
Institute for Carbon Composites donated by
Christoph Ebel
289 - 15070
554.01.439
289 - 15097