《纺织复合材料》课程参考文献（3-D textile reinforcements in composite materials）08 3-D forming of continuous fibre reinforcements for composites

8 3-D forming of continuous fibre reinforcements for composites O.K.BERGSMA,F.VAN KEULEN,A.BEUKERS, H.DE BOER AND A.A.POLYNKINE 8.1 Introduction 8.1.1 The earliest fibres,fabrics and composite structures The control of fire and the spinning of continuous strands of fibres are prob- ably the most important discoveries humans ever made.Both inventions made it possible for a naked human to survive in non-tropical conditions. Yarns and derivatives,like robes and textile fabrics,provided humans with a portable and personal tropical microclimate by clothes and structures so that they could withstand most climatological conditions.It made humans able to migrate from the crowded and unhealthy tropical zones to the large, cool plains and mountainous areas,free of diseases,but rich in animals,veg- etables,minerals and water.Compared with animal skin,flexible textile was 豆 a big step forward.The usage of light fabrics that were adjustable to local conditions made a big and relatively fast migration of hunters and gather- ers possible over all continents,except Antarctica [1].Humans could only use local natural growing fibres.They differ from modern artificial synthetic fibres in length.Instead of the continuous filaments,nature offers only short fibres,like animal hair.These protein-based fibres are provided by animals, such as sheep,goats,camels,llamas and rabbits.Various forms of vegetable cellulose-based fibres were available as well:in a hairy form taken from seeds(cotton)and fruits(coir)or as fibres extracted from basts and leaves, like jute,sisal,hemp,flax,yucca,palm,rice,grass,ramie and rattan. Several of these materials could instantly be used to make basket-like structures or to wattle hedges and walls.However,to handle and to make the staple fibres suitable for knitting and weaving,as shown in Fig.8.1,the spinning and intertwining of yarns was essential.A distaff,a small portable wooden spinning wheel on a vertical axle(Fig.8.2),had already been known in prehistoric times,far before the wooden wheel on the horizontal axle was invented to make wheeled transport possible.Depending on the local climate,people started to use ropes,felt (paper-like textile)and woven 241

8.1 Introduction 8.1.1 The earliest fibres, fabrics and composite structures The control of fire and the spinning of continuous strands of fibres are prob￾ably the most important discoveries humans ever made. Both inventions made it possible for a naked human to survive in non-tropical conditions. Yarns and derivatives, like robes and textile fabrics, provided humans with a portable and personal tropical microclimate by clothes and structures so that they could withstand most climatological conditions. It made humans able to migrate from the crowded and unhealthy tropical zones to the large, cool plains and mountainous areas, free of diseases, but rich in animals, veg￾etables, minerals and water. Compared with animal skin, flexible textile was a big step forward. The usage of light fabrics that were adjustable to local conditions made a big and relatively fast migration of hunters and gather￾ers possible over all continents, except Antarctica [1]. Humans could only use local natural growing fibres.They differ from modern artificial synthetic fibres in length. Instead of the continuous filaments, nature offers only short fibres, like animal hair. These protein-based fibres are provided by animals, such as sheep, goats, camels, llamas and rabbits. Various forms of vegetable cellulose-based fibres were available as well: in a hairy form taken from seeds (cotton) and fruits (coir) or as fibres extracted from basts and leaves, like jute, sisal, hemp, flax, yucca, palm, rice, grass, ramie and rattan. Several of these materials could instantly be used to make basket-like structures or to wattle hedges and walls. However, to handle and to make the staple fibres suitable for knitting and weaving, as shown in Fig. 8.1, the spinning and intertwining of yarns was essential. A distaff, a small portable wooden spinning wheel on a vertical axle (Fig. 8.2), had already been known in prehistoric times, far before the wooden wheel on the horizontal axle was invented to make wheeled transport possible. Depending on the local climate, people started to use ropes, felt (paper-like textile) and woven 8 3-D forming of continuous fibre reinforcements for composites O.K. BERGSMA, F. VAN KEULEN, A. BEUKERS, H. DE BOER AND A.A. POLYNKINE 241 RIC8 7/10/99 8:26 PM Page 241 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:31:28 AM IP Address: 158.132.122.9

242 3-D textile reinforcements in composite materials SuruC 8.1 Weaving of plain fabrics. wo'ssaudmaupeaupoow//:dny Aq palnad WV8Z:IE:ZI I IOZ 'ZZ Aenur 'Aupines 8.2 Spinning of yarns. fabrics of different natural materials for several purposes.In many parts of the world the same ancient design of clothes,tapes,baskets and tents,all continuous fibre structures,are still in use and almost unchanged.Up to this day,3-D textile structures still offer nomadic families the best protection against extreme temperatures.The peaked black tent,an example of a con- trolled draped fabric,is used in the hot dry deserts.In the cold snowy areas circular tents,yurts,are used.These circular trellis structures,limited in shear by a doorframe and a circumferential rope,are covered with wattle and felt.As soon as communities started to settle,the flexible and foldable textile structures were transformed,step by step,in more protective rigid wattle and daub or straw reinforced clay structures.In fact,it was the first creation of artificial composites,a combination of different materials to

fabrics of different natural materials for several purposes. In many parts of the world the same ancient design of clothes, tapes, baskets and tents, all continuous fibre structures, are still in use and almost unchanged. Up to this day, 3-D textile structures still offer nomadic families the best protection against extreme temperatures. The peaked black tent, an example of a con￾trolled draped fabric, is used in the hot dry deserts. In the cold snowy areas circular tents, yurts, are used. These circular trellis structures, limited in shear by a doorframe and a circumferential rope, are covered with wattle and felt. As soon as communities started to settle, the flexible and foldable textile structures were transformed, step by step, in more protective rigid wattle and daub or straw reinforced clay structures. In fact, it was the first creation of artificial composites, a combination of different materials to 242 3-D textile reinforcements in composite materials 8.1 Weaving of plain fabrics. 8.2 Spinning of yarns. RIC8 7/10/99 8:26 PM Page 242 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:31:28 AM IP Address: 158.132.122.9

3-D forming of continuous fibre reinforcements for composites 243 Table 8.1.Elastic properties of some natural composites compared with steel Material Density Young's Yield stress Yield Elastic (kg/m3×103) modulus (N/m2×10) strain energy/ (N/m2×10) (%) weight (J/kg) Steel 0.2 carbon 7.8 210 773 0.2 99 quenched Piano wires, 7.8 210 3100 0.8 1590 springs Animal Sinew 1.3 1.24 103 4.1 1620 Buffalo horn 1.3 2.65 -124 -3.2 1530 Bovine bone 2.1 22.6 -254 -1.4 846 lvory 1.9 17.5 217 1.2 685 Hardwood Ash 0.69 13.4 165 1.0 1196 poo Birch 0.65 16.5 137 1.0 1050 Elm 0.46 7.0 68 1.0 740 Wych elm 0.55 10.9 105 1.0 950 Oak 0.69 13.0 7 1.0 703 Softwood Scots pine 0.46 9.9 89 0.9 870 10 Taxus brevifolia 0.63 10.0 116 1.3 1100 Notes: 1 Northern hardwoods,sinew and horn were the basic structural materials for the laminated composite bows and chariots from Mesopotamia and Egypt. 2 Taxus baccata was used for medieval longbows. 3 Horn,a natural thermoplastic polymer was especially applied in the 8 compression loaded areas. 4 Sinew,superior in tension,was employed for strings and bow-reinforcement; more in general it was used as a shrinking (smart)robe to encapsulate and to connect different components. obtain improved or modified properties.The earliest laminated composite structures,like composite bows and chariots,were glued layered structures of natural composites such as wood,bone,sinew and horn [2].They were all fibrous materials,based on cellulose,collagen and keratin,which had very specific capabilities,already discovered and understood by the prehis- toric craftsman (Table 8.1). All applications mentioned in this part of the Introduction,from textile structures more than 50 to 8 millennia ago to the composite shelters, bows and chariots from 12 to 5 millennia ago were not developed overnight, the structures were sometimes very complex and took probably centuries

obtain improved or modified properties. The earliest laminated composite structures, like composite bows and chariots, were glued layered structures of natural composites such as wood, bone, sinew and horn [2]. They were all fibrous materials, based on cellulose, collagen and keratin, which had very specific capabilities, already discovered and understood by the prehis￾toric craftsman (Table 8.1). All applications mentioned in this part of the Introduction, from textile structures more than 50 to 8 millennia ago to the composite shelters, bows and chariots from 12 to 5 millennia ago were not developed overnight, the structures were sometimes very complex and took probably centuries 3-D forming of continuous fibre reinforcements for composites 243 Table 8.1. Elastic properties of some natural composites compared with steel Material Density Young’s Yield stress Yield Elastic (kg/m3 ¥ 103 ) modulus (N/m2 ¥ 106 ) strain energy/ (N/m2 ¥ 109 ) (%) weight (J/kg) Steel 0.2 carbon 7.8 210 773 0.2 99 quenched Piano wires, 7.8 210 3100 0.8 1590 springs Animal Sinew 1.3 1.24 103 4.1 1620 Buffalo horn 1.3 2.65 -124 -3.2 1530 Bovine bone 2.1 22.6 -254 -1.4 846 Ivory 1.9 17.5 217 1.2 685 Hardwood Ash 0.69 13.4 165 1.0 1196 Birch 0.65 16.5 137 1.0 1050 Elm 0.46 7.0 68 1.0 740 Wych elm 0.55 10.9 105 1.0 950 Oak 0.69 13.0 97 1.0 703 Softwood Scots pine 0.46 9.9 89 0.9 870 Taxus brevifolia 0.63 10.0 116 1.3 1100 Notes: 1 Northern hardwoods, sinew and horn were the basic structural materials for the laminated composite bows and chariots from Mesopotamia and Egypt. 2 Taxus baccata was used for medieval longbows. 3 Horn, a natural thermoplastic polymer was especially applied in the compression loaded areas. 4 Sinew, superior in tension, was employed for strings and bow-reinforcement; more in general it was used as a shrinking (smart) robe to encapsulate and to connect different components. RIC8 7/10/99 8:26 PM Page 243 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:31:28 AM IP Address: 158.132.122.9

244 3-D textile reinforcements in composite materials of experimentation and evolution.The results are still striking for the craftsmanship,knowledge of materials and the sophisticated manu- facturing processes [2].For a successful introduction of modern artificial composites,equal understanding must be developed and supported by modern mathematical modelling and computers.Besides the application of new synthetic materials,the biggest break with the past will be the introduction of low-cost and fast manufacturing and simulation equipment to replace the time-consuming,high-priced and mystic skills of craftsmen. 8.1.2 The renaissance of fibre reinforced composites During the second half of this century,the last decade in particular,a true revival started of using light-weight composite structures for many techni- cal applications.In the beginning,the introduction of fibre reinforced poly- 酒 mers was only driven by particular electromagnetic characteristics.More pooM than a century ago,cotton reinforced rubbers and phenolics were used for insulators.Later,glass fibre reinforced polyesters were applied for radomes, minehunters and minesweepers.In the 1980s,high-technology composites based on carbon-and aramid-fibre reinforced epoxies became popular to 2-0 improve the structure performance of spacecraft,military aircraft,heli- copters and all kinds of sports and racing equipment.Initially,the sky was A the limit as far as the price was concerned.Nowadays,cost reduction during manufacturing and operation is the technology driver,and examples are large structures in civil applications(carbon fibre reinforcement of bridges 二一8、 and buildings)or in corrosive chemical or marine environments(glass fibre reinforced bridges,piers,pipes,tanks,etc.).One of the latest developments is the application of continuous fibre reinforced polymers to protect people against impact and fire and a more general tendency to design means of transport which are less damaging to our environment.Some typical exam- ples are shown in Fig.8.3. Like in prehistoric times,the reinforcing fibrous materials are applied in different forms;short or continuous,as tapes,mats or plain weaves. Although the vegetable fibres mentioned earlier are gaining renewed inter- est,most structural applications are now reinforced with synthetic fibres with constant quality.Inorganic fibres are applied such as glass,metal and silica,organic fibres based on natural cellulose and protein polymers or syn- thetic fibres based on condensation or addition polymers.There are innu- merable types of synthetic fibres,such as single filaments or tows,neat or post-treated,stretched or carbonized.Nowadays,the most popular rein- forcing fibres with respect to price-performance are the low-cost(E)glass fibres and the high modulus(HM)aramid-and high-tenacity (HT)carbon fibres (Table 8.2)

of experimentation and evolution. The results are still striking for the craftsmanship, knowledge of materials and the sophisticated manu￾facturing processes [2]. For a successful introduction of modern artificial composites, equal understanding must be developed and supported by modern mathematical modelling and computers. Besides the application of new synthetic materials, the biggest break with the past will be the introduction of low-cost and fast manufacturing and simulation equipment to replace the time-consuming, high-priced and mystic skills of craftsmen. 8.1.2 The renaissance of fibre reinforced composites During the second half of this century, the last decade in particular, a true revival started of using light-weight composite structures for many techni￾cal applications. In the beginning, the introduction of fibre reinforced poly￾mers was only driven by particular electromagnetic characteristics. More than a century ago, cotton reinforced rubbers and phenolics were used for insulators. Later, glass fibre reinforced polyesters were applied for radomes, minehunters and minesweepers. In the 1980s, high-technology composites based on carbon- and aramid-fibre reinforced epoxies became popular to improve the structure performance of spacecraft, military aircraft, heli￾copters and all kinds of sports and racing equipment. Initially, the sky was the limit as far as the price was concerned. Nowadays, cost reduction during manufacturing and operation is the technology driver, and examples are large structures in civil applications (carbon fibre reinforcement of bridges and buildings) or in corrosive chemical or marine environments (glass fibre reinforced bridges, piers, pipes, tanks, etc.). One of the latest developments is the application of continuous fibre reinforced polymers to protect people against impact and fire and a more general tendency to design means of transport which are less damaging to our environment. Some typical exam￾ples are shown in Fig. 8.3. Like in prehistoric times, the reinforcing fibrous materials are applied in different forms; short or continuous, as tapes, mats or plain weaves. Although the vegetable fibres mentioned earlier are gaining renewed inter￾est, most structural applications are now reinforced with synthetic fibres with constant quality. Inorganic fibres are applied such as glass, metal and silica, organic fibres based on natural cellulose and protein polymers or syn￾thetic fibres based on condensation or addition polymers. There are innu￾merable types of synthetic fibres, such as single filaments or tows, neat or post-treated, stretched or carbonized. Nowadays, the most popular rein￾forcing fibres with respect to price–performance are the low-cost (E) glass fibres and the high modulus (HM) aramid- and high-tenacity (HT) carbon fibres (Table 8.2). 244 3-D textile reinforcements in composite materials RIC8 7/10/99 8:26 PM Page 244 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:31:28 AM IP Address: 158.132.122.9

3-D forming of continuous fibre reinforcements for composites 245 wo'ssaidmau'peaupoow/:dny Aq palnad 8.3 Some typical examples of continuous fibre reinforced products. 8.1.3 Industrial manufacturing of composite components A successful introduction of reinforced polymer materials and components depends on the availability of fast and reliable manufacturing techniques. In general,new materials are more expensive than the materials they have to compete with.Added value in mechanical,chemical or physical charac- teristics is only convincing when the price performance is competitive.No parameter is so determinant for the price-performance ratio of advanced structures as the cost to manufacture.Once the materials have been accepted and established,the performance per unit weight gains impor-

8.1.3 Industrial manufacturing of composite components A successful introduction of reinforced polymer materials and components depends on the availability of fast and reliable manufacturing techniques. In general, new materials are more expensive than the materials they have to compete with. Added value in mechanical, chemical or physical charac￾teristics is only convincing when the price performance is competitive. No parameter is so determinant for the price–performance ratio of advanced structures as the cost to manufacture. Once the materials have been accepted and established, the performance per unit weight gains impor- 3-D forming of continuous fibre reinforcements for composites 245 8.3 Some typical examples of continuous fibre reinforced products. RIC8 7/10/99 8:26 PM Page 245 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:31:28 AM IP Address: 158.132.122.9