Page 321 - Fiber Fracture

Fiber Fracture
M . Elices and J . Llorca (Editors)
0 2002 Elsevier Science Ltd . All rights reservcd

FRACTURE OF NATURAL POLYMERIC

FIBRES

Chris topher Viney

Department of Chemistq Heriot- Watt University. Edinburgh EH14 4AS. Scotland. UK

Introduction ..................................... 305
A Traditional View of Natural Fibres ..................... 305
Nature Revisited ................................ 306
Some Thoughts on the Meaning of ‘Brittle’ .................. 307
Fracture of Natural Self-Assembled Fibres ..................... 308
Self-Assembly Favours the Formation of Fibrous. Hierarchical Structures . . 308
Primary and Secondary Bonds Can Have Direct. Distinguishable. Comple-
mentary Effects on Fibre Mechanical Properties ........... 309
A Hierarchical Structure Optimises Toughness ................ 310
Water Plays Multiple Roles in the Assembly and Stabilisation of Natural
Fibres ................................. 311
The Fracture Characteristics of Natural Fibres Can Be Sensitive to Prior
Deformation .............................. 312
In a Hierarchical Fibre Microstructure. Molecules That Have ‘Melted’ Can
Continue to Carry Loads Usefully .................. 313
The Experimental Methods Used for Characterising the Failure Strength and
Other Mechanical Properties of Fibres Must Be Appraised Carefully 315
Conditioning ............................... 315
Cross-Sectional Area Characterisation .................. 316
Force Characterisation .......................... 317
The Statistical Basis of Fibre Failure Analysis ............. 317
Echinoderm Collagens: Fibre Optimisation in Smart Composites ......... 320
Tensile Property Control ............................ 320
Tapered Fibres ................................. 320
Acknowledgements ................................. 325
References ...................................... 325