![Function of an elastic
compensation structure
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Load distribution characterization
The Arm structure has many
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•A more uniform load distribution
•Increase the ski stiffness
•Fill the unloaded ski shovel
•Increase ski performances:
Edge switching quickness
Edge catching quickness
Carving precision
Reactiveness at out of a turn
Vibration damping](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-3-320.jpg)
![Padua workbench
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blizzard SCS
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Slytech bench](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-4-320.jpg)
![Results
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Nspitf-PD ICE HL_30°
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HEEL
LOAD
TIP](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-6-320.jpg)
![Results and Comparisons
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Nspitf-PD ICE HL_30°
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WB300
HEEL
LOAD
TIP
BR300
ALU
WOOD
LARGE
EFFECT](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-7-320.jpg)
![Results and Comparisons
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Nspitf-PD ICE HL_30°
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BR300
PU
C H B
SMALL
EFFECT](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-8-320.jpg)
![Chemnitz (DE) workbench
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ski length from tail to tip [mm]
Nspitf-CH MI LL-30°
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WOOD (B)
CHB (C)
ALU (D)
Limitation](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-9-320.jpg)
![0,00E+00
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From tail to tip [mm]
Nspitf - Nordica bench
original AA
ALU
PU
C H B
WB 300
portabraccetto
Nordica workbench
The Nordica bench curves
show an high influence due
to the aluminum support
Even if the benches are showing
different parameters, the same
configuration trend can be noticed](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-10-320.jpg)
![Foam: a new device for edge
load profile investigation
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Soft snow
Average snow
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Federolf’s snow characterization Foam as snow surrogate
Snow indenter](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-15-320.jpg)
![Results
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SLYTECH BENCH
FARO SCANARM
SMARTSCOPE](https://image.slidesharecdn.com/41084130-0b02-42f1-af47-021f9614c6f3-150614181548-lva1-app6891/85/Alex-Persico-Power-Point-17-320.jpg)
Alex Persico Power Point
- 1. Caratterizzazione di materiali per applicazioni innovative in ambito sciistico Materials Characterization For The Innovation Of Ski Equipments Alex Persico Laurea Magistrale in Ingegneria dei Materiali Relatore: Prof. Nicola Petrone Correlatore: Ing. Giorgio Grandin 10/10/2014
- 2. Objective and main steps Elastic compensation structure • Prototypes • Workbenches • In-field tests • Results Foam surrogate for edge load distribution analysis • Foam characterization • Laser Scan devices for traces evaluation • Results
- 3. Function of an elastic compensation structure 0 20 40 60 80 100 120 140 0 200 400 600 800 1000 1200 1400 1600 Load[N] Load distribution from tail to tip [mm] Load distribution characterization The Arm structure has many effects: •A more uniform load distribution •Increase the ski stiffness •Fill the unloaded ski shovel •Increase ski performances: Edge switching quickness Edge catching quickness Carving precision Reactiveness at out of a turn Vibration damping
- 4. Padua workbench Angle [°] Load [N] 0 500 10 600 20 700 30 850 40 1000 50 1200 60 1400 0 20 40 60 80 100 120 140 160 0 500 1000 1500 Load[N] Load distribution from tail to tip[mm] Angle: 40° blizzard SCS spitfire Heel Tip Force Slytech bench
- 5. Aluminum support developed by Eng. Federico Signoretto (2013) ARM Prototypes WOOD (PD) ALU (PD) PU PU + C CHB OAK WOOD Hand-crafted Aluminum alloy, Ergal 7075 - T6 Al 5,1-6,1%Zn; 2,1-2,9%Mg; 1,2-2%Cu SG 95 Mix ratio (A:A-LP):(50:50) B:150 Mixing time 45 s to 60 s Resin temperature 40 °C Mould temperature 70 °C Curing temperature 70 °C Curing time in mould 70 min Vacuum Casting ARM Prototypes Nordica
- 6. Results 0 20 40 60 80 100 120 140 0 200 400 600 800 1000 1200 1400 1600 Load[N] Load cells: from tail to tip[mm] Nspitf-PD ICE HL_30° original HEEL LOAD TIP
- 7. Results and Comparisons 0 20 40 60 80 100 120 140 0 200 400 600 800 1000 1200 1400 1600 Load[N] Load cells: from tail to tip[mm] Nspitf-PD ICE HL_30° original ALU WB300 HEEL LOAD TIP BR300 ALU WOOD LARGE EFFECT
- 8. Results and Comparisons 0 20 40 60 80 100 120 140 0 200 400 600 800 1000 1200 1400 1600 Load[N] Load cells: from tail to tip[mm] Nspitf-PD ICE HL_30° original PU C H B HEEL LOAD TIP BR300 PU C H B SMALL EFFECT
- 9. Chemnitz (DE) workbench Angle Applied Load 0° 350 N 20° 500 N 30° 600 N 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 Load[N] ski length from tail to tip [mm] Nspitf-CH MI LL-30° original PU (A) WOOD (B) CHB (C) ALU (D) Limitation
- 10. 0,00E+00 1,00E+09 2,00E+09 3,00E+09 4,00E+09 5,00E+09 6,00E+09 7,00E+09 8,00E+09 9,00E+09 1,00E+10 0 500 1.000 1.500 FlexmodulusEJ [Nmm^3/micron] From tail to tip [mm] Nspitf - Nordica bench original AA ALU PU C H B WB 300 portabraccetto Nordica workbench The Nordica bench curves show an high influence due to the aluminum support Even if the benches are showing different parameters, the same configuration trend can be noticed
- 11. Arm stiffness characterization NORDICA DII Arm fixed to the ski Aluminum support Arm fixed to a rigid support
- 12. Ski and Arms stiffness • Even if CHB is «softer» than PU, CHB has higher influence on total ski+ arm stiffness K
- 13. In-field test sessions METHOD & TESTERS The skiers test all the configuration consequently, filling the evaluation form at the end of each run Two tests STUBAI end of July • Five Nordica testers • Only one filled evaluation form • WOOD arm was not tested HINTERTUX early September • Three testers: one ex-racer and two expert amateurs • Three personal evaluation form completed • All arms tested • Blind testing
- 14. In field test results Summarizing: The CHB and WOOD during Stubai and Hintertux test respectively had best scores; the ski behaves like a «longer ski». The quality percived is the carving precision: all the points of the ski edge traveling through the same track on the snow surface during a turn. n=1 n=3
- 15. Foam: a new device for edge load profile investigation 0,0 500,0 1000,0 1500,0 2000,0 2500,0 3000,0 3500,0 4000,0 0,0 5,0 10,0 15,0 Force[N] Displacement [mm] θ=40° Schiuma_A Schiuma_RP1 Schiuma_RP2 Schiuma_C Schiuma_D Schiuma_G Schiuma_PEDILEN Soft snow Average snow Hard snow Federolf’s snow characterization Foam as snow surrogate Snow indenter
- 16. Traces acquisition FARO SCANARM SMARTSCOPE FLASH
- 17. Results 0 20 40 60 80 100 120 700 800 900 1000 1100 Load[N] Load distribution cells 11 12 13 [mm] 40° cells: 11 12 13 0 20 40 60 80 100 120 140 160 700 800 900 1000 1100 Load[N] Load distribution cells 11 12 13 [mm] 50° cells 11 12 13 0 10 20 30 40 50 60 70 80 90 700 800 900 1000 1100 Load[N] Load distribution cells 11 12 13 [mm] 60° cells 11 12 13 0,0 200,0 400,0 600,0 800,0 1000,0 1200,0 1400,0 1600,0 1800,0 0,0 5,0 10,0 15,0 20,0 Force[N] Displacement [mm] θ=40° Schiuma_ RP1 Soft snow Average snow Hard snow SLYTECH BENCH FARO SCANARM SMARTSCOPE
- 18. Conclusions Elastic compensation structure: • CHB and WOOD arms better influenced the ski •Importance of the subjective evaluation form •More in-field tests are necessary to create statistical results •New prototypes have to be engineered and tested Foam as snow surrogate: • New foam materials can be tested in order to match the snow properties • The parameters to be considered are: density, a small spring back, constant thickness of the keyboard. • Advantage: a “detailed” edge load distribution characterization can be performed without the array of load cells • Disadvantage: large amount of foam needed. THANKS FOR THE ATTENTION