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1Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of Mobility – Looking Backward and Forward
Prof. Dr.-Ing. Frank Walther
Materials Test Engineering (WPT), TU Dortmund University
Innovative Leichtbauwerkstoffe auf Kunststoff- und Holzbasis als Impulsgeber der Mobilität – Rückblick und Ausblick
2Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
1. Introduction
Scientific Areas
3Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Carbon Fiber Reinforced Plastics (CFRP)
Laminates Hybrid Structures
Vulcanized Fiber Wood
Wood Wood-Plastic-Composites (WPC)
Measurement Techniques
AcousticEmission
Fiber-Bragg-Grating-Sensors
Fundamentals Applications
1. Introduction
Innovative Lightweight Composites and Hybrid Compounds
4Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
2. Testing Systems
Mechanical and Corrosion Labs
5Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
2. Testing Systems
Mechanical Lab
Universal Testing Systems AGS-X and AG-X
5kN … 250kN
Thermostatic Chamber TCLHumidity Chamber TCH
ServopulserL-type (20kN) Micro-Magnetic
Testing System MMT-500 (500N)
Ultrasonic Fatigue Testing System USF-2000 (20kHz)
ServopulserU-type (100kN)
6Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
3. Measurement and Testing Methods
Research Qualifications
7Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
3. Measurement and Testing Methods
Sensor Systems
mechanical
thermal
electrical
acoustical
magnetic
optical
Extensometer
Thermocouples
Thermocamera
Direct current
Alternating current
Barkhausen noise
Ferritescope
GMR
Digital image correlation
Mechanical vibration / Acoustic emission
8Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Fatigue life
Str
ess
amp
litu
de
August Woehler (1819 - 1914)
Shipton, 1874
Eschede, 1998 Cologne, 2008
Linz, 1875
Demerits:- Only total life is considered- No information about failure mechanism- Extensive testing (time, costs !)
Shortcomings ? Intelligent accelerated testing ! Basis for process design / understanding,
life cycle evaluation
3. Measurement and Testing Methods
Woehler Curve
9Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
3. Measurement and Testing Methods
Short-Time Load Increase Procedure – Staircase or „Cyclic Tensile Test“
Material reaction:Material reaction:and
and
RAPID (Rapid Fatigue Performance
Identification Method)
10Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Wood(Beech, Spruce)
Wood Plastic Composites(WPC)
Vulcanized Cotton Fiber(Vulkanfiber)
4. Results
Innovative Lightweight Products Made of Vulcanized Fiber, Wood and WPC
11Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Young's modulus Tensile strengthMaximum
strain
Highhumidity 30% 40%
Lowhumidity
Ideal for forming processes
After drying original properties(reversibel process)
4. Results
Influence of Humidity on Mechanical Properties of Vulcanized Fiber
12Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Speed [mm/min] 1 5 10 100 1.000 3.000 720.000 900.000 1.200.000
Young's modulus[MPa]
8.264 8.461 8.865 9.288 15.651
Tensile strength[MPa]
101 106 110 115 124 128 130 145 161
Maximum strain[%]
6,78 7,28 7,04 7,12 5,96
High strain rate: Increase in strength ~ 60%
4. Results
Influence of Strain Rate on Mechanical Properties of Vulcanized Fiber
HITS-T
HPV-1/-2
13Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
4. Results
Tensile and Fatigue Properties of Timber and Timber Structures
14Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Beech
Spruce
WPC (50% PVC/50% wood)
WPC (25% PE/75% wood)
4. Results
Influence of Strain Rate on Tensile Deformation of Vulcanized Fiber, Wood and WPC
15Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Beech
Spruce
WPC (50% PVC/50% wood)
WPC (25% PE/75% wood)
4. Results
Influence of Humidity on Tensile Deformation of Vulcanized Fiber, Wood and WPC
16Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Beech
Spruce
WPC (50% PVC/ 50% wood)
WPC (25% PE/75% wood)
T1
T2
T3
4. Results
Fatigue Behavior of Vulcanized Fiber, Wood and WPC
17Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
0°glued 10° 90°
Specimen Geometry
• DIN EN ISO 527-2:2012
• Flat tensile specimen
0°
Fiber Orientation
0°
10°
90°
Glued joint
• Hysol 9492 (epoxy resin adhesive)
• Glass balls to control joint gap
4. Results
Fiber Orientation and Geometry of Beech Wood
18Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Pyrometer
• Contactless operation
∆T = Tspecimen - Tambient
Thermocouples
• Fixed with tape
- Influencing the structure- Results vary widely
T2
T1
T3
Used
Thermocouples
• Fixed with wood glue
- Fixation dissolves
T2
T1
T3
∆T = T2 - 0.5 (T1+T3)∆T = T2 - 0.5 (T1+T3)
4. Results
Temperature Measurement of Beech Wood Under Fatigue Loading
19Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
• 0° and 10° are similar (90-100%)
• 90° has lowest stress amplitudes (8-12%)
• Glued joints show stress amplitudes of 87-88% of 0°
Average of 3 tests in each category
4. Results
Comparison of Stress Amplitudes for Beginning of Damage and Fracture
25
46
20Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
• Construction of Woehler curves based on tensile and single step tests
• Further tests to define endurance limit
4. Results
Influence of Fiber Orientation on Woehler Curves
21Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Side view Top view
Rear view
Glass balls
• 0.4 mm diameter
Adhesive layer
Fracture surface
Wood fiber structure
Source: Prof. Kaloudis, University of Applied Sciences Aschaffenburg, 2013
4. Results
CT Investigations on Glued Beech Wood Specimens
22Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
4. Results
Fatigue Behavior of CFRP/Blind Rivet Nut Hybrid Compounds
CFRP
Blind Rivet Nut
23Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
C-Fibre G-Fibre Steel
E-Modul [GPa]
~230 86 ~210
Density[g/cm3]
1.80 2.54 ~7.85
CFRP
4. Results
Fatigue Behavior of CFRP/Blind Rivet Nut Hybrid Compounds
Blind Rivet Nut
head
shaft
formed part
threaded part
24Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
N
sa
Fa Fa
sa
∆sa = sa,max - sa,min
Fa
sa
4. Results
Fatigue Behavior of CFRP/Blind Rivet Nut Hybrid Compounds
Load
ampl
itude
Fa
Dis
plac
emen
tam
plitu
des a
Number of cycles N (x 104)
Load amplitude Fa
Cha
nge
in d
ispl
acem
ent
s a
25Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
CFRP/Aluminium
CFRP/Stainless Steel
4. Results
Corrosion Behavior of CFRP/Aluminium and CFRP/Steel Compounds
26Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
4. Results
Intrinsic Hybrid Structures
Steel: Isotropic High Density (7.85 g/cm³) Young`s Modulus 210 GPa
CFRP: Anisotropic Low Density (1.5 g/cm³) Young´s Modulus ǁ 150 GPa
Hybrid Structures: Combination of steel and CFRP Optimization of the component regarding
mechanical load Reinforcement by CFRPWeight reduction
Source: LiA, Paderborn
Source: LiA, Paderborn
27Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
4. Results
Intrinsic Hybrid Structures
28Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Industry
Cooperation Partners
„Teaching and Research are of great importance, but as a
progressive department we`re moreover a Partner of the Industry
for developing and implementing real tasks and analysis.“
29Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
Universal Testing Systems AGS-X and AG-X
5kN … 250kN
Thermostatic Chamber TCLHumidity Chamber TCH
ServopulserL-type (20kN) Micro-Magnetic
Testing System MMT-500 (500N)
Ultrasonic Fatigue Testing System USF-2000 (20kHz)
ServopulserU-type (100kN)Stand 8b / H16
Industry
Cooperation Partners
30Innovative Lightweight Materials on Polymer and Wood Basis as Instigators of MobilityFrank Walther | 26.10.2014
TU Dortmund UniversityFaculty of Mechanical EngineeringDepartment of Materials Test EngineeringProf. Dr. Frank WaltherBaroper Str. 303D-44227 Dortmund (Germany)
Phone: +49 (231) 755 8028Fax: +49 (231) 755 8029Email: frank.walther@tu-dortmund.deWeb: www.wpt-info.de
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