60 3-D textile reinforcements in composite materials costs,manufacturability,mechanical performance,long-term behaviour, repairability and recyclability.As discussed before,composites offer some important benefits over metals,such as mechanical performance,long-term behaviour (no corrosion),high damping and low-energy expense for raw material manufacturing.On the other hand,there are currently no adequate solutions for high-volume manufacturing techniques for long-fibre rein- forced composites,costs,repair and recycling.Therefore,no automotive manufacturer has so far applied this class of material for structural com- ponents in real high-volume models(50000 to 300000 cars per year). Of special interest is the use of composites in chassis applications,as in this field the anisotropy of the material can be used to create all-new design concepts,allowing a significant reduction in component numbers and a very marked weight reduction compared with steel.It is,for example,possible to realize beam elements with a very high bending stiffness and low tor- sional stiffness,or vice versa. In order to evaluate the applicability of textile structural composites, Daimler-Benz has manufactured and tested a 3-D reinforced engine mount at laboratory level within the framework of a research project.One com- ponent has been produced using 20 conventionally woven glass fibre layers; the other one is based on a single 3-D weaving integrating these layers in a single preform.The result is a significant decrease in manufacturing time (see Fig.2.11),which is due to a reduction in manual work (cutting and laminating).It is expected that cycle times of less than 10 minutes are possible when applying an optimized RTM process. Bending and fatigue tests have shown that the composite components 豆 hours Vacuum Preparation 2.5 ■ Lamination/ Impregnation ◇ Pre-Forming ■ Cutting 1,5 0.5 2-D weaving 3-D weaving 3-D weaving Hand lamination Hand lamination automated RTM-Process 2.11 Manufacturing time for composite engine mounts.costs, manufacturability, mechanical performance, long-term behaviour, repairability and recyclability. As discussed before, composites offer some important benefits over metals, such as mechanical performance, long-term behaviour (no corrosion), high damping and low-energy expense for raw material manufacturing. On the other hand, there are currently no adequate solutions for high-volume manufacturing techniques for long-fibre rein￾forced composites, costs, repair and recycling. Therefore, no automotive manufacturer has so far applied this class of material for structural com￾ponents in real high-volume models (50 000 to 300 000 cars per year). Of special interest is the use of composites in chassis applications, as in this field the anisotropy of the material can be used to create all-new design concepts, allowing a significant reduction in component numbers and a very marked weight reduction compared with steel. It is, for example, possible to realize beam elements with a very high bending stiffness and low tor￾sional stiffness, or vice versa. In order to evaluate the applicability of textile structural composites, Daimler-Benz has manufactured and tested a 3-D reinforced engine mount at laboratory level within the framework of a research project. One com￾ponent has been produced using 20 conventionally woven glass fibre layers; the other one is based on a single 3-D weaving integrating these layers in a single preform. The result is a significant decrease in manufacturing time (see Fig. 2.11), which is due to a reduction in manual work (cutting and laminating). It is expected that cycle times of less than 10 minutes are possible when applying an optimized RTM process. Bending and fatigue tests have shown that the composite components 60 3-D textile reinforcements in composite materials 2.11 Manufacturing time for composite engine mounts. RIC2 7/10/99 7:26 PM Page 60 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:29:45 AM IP Address: 158.132.122.9