Polymer composites damage tolerance

Damage tolerance of fibre reinforced thermoplastic composites Processing of polymer matrices using resin transfer moulding Fractal analysis of wear in short-fibre reinforced thermoplastic composites Rheology flow behavior of associative polymers in coating applications Kevlar-thermoplastic composites... 

Rag Raghava, R. S. Development and characterization of thermosetting-thermoplastic polymer blends for applications in damage-tolerant composites. J. Polym. Sci. Part B Polym. Phys. 26 (1988) 65-81. 

The ceramic matrix composites (CMCs) contain brittle fibers and a brittle matrix. This combination ends up in a damage tolerant material. CMCs are of interest to thermostmctural applications. They consist of ceramics or carbon reinforced with continuous ceramic or carbon fibers. Their mechanical behavior displays several typical features that differentiate them from the other composites (such as polymer matrix composites, metal matrix composites, etc. .. ) and from the homogeneous (monolithic) materials. 

As compared to laminated composite, there is no doubt that the impact tolerance of the 3-D woven fabric reinforced polymer composite has been enhanced dramatically due to the 3-D network structme and the improved transverse shear resistance. However, it is clear that even repeated low velocity impact can cause significant damage. Therefore, tike laminated composite and sandwich composite, 3-D woven fabric reinforced polymer composite also calls for self-healing capabilities. 

To this point the effect ofthermoplastics on DGEBA or TGAP,di- andtri-fimctional epoxies, has been discussed. However, when epoxies are reinforced with fibers to form polymer composites for use as structural materials, atetra-2,3-epoxypropyl epoxy is frequently used because its greater crosslinking provides a more damage tolerant epoxy. Other special epoxies such as the 2,3-epo qjropyl ether of bis(hydroxy )fluorene are of interest as well. 

The absorber materials are in most cases very tough polymer composites. These may consist of aramid fibres in a tough matrix such as heavily plasticised and toughened polymer resin or neoprene. Polyethylene fibre composites are also widely used, although typically these consist of pressure-consoUdated laminates rather than using resin infiltration. Most systems have a covering of fibre composite or fabric to provide impact resistance and to enhance the damage tolerance of the... 

Conventional wisdom on the durability of polymer composites is that FRP composite products can be in-service for a very long time unlike steel or concrete. FRP composite materials can provide a longer service life because of lower therm effects, better mechanical performance, and higher damage tolerance than conventional materials provided they are tailor-made with a high degree of precision... 

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