In automotive applications lightweight composite components will promote performance with improved acceleration, braking, handling and fuel efficiency. In evaluating composite performance it is often the very advantage these space-age materials provide that misguides the average person. Weight is traditionally an indicator of strength, however composites should never be evaluated on this basis. Just because a fiberglass hood or fender feels heavy does not necessarily mean it is strong.

Nor does it mean a very lightweight composite is necessarily weak. Properly engineered, advanced composites can provide very light weight and exceptional strength. High performance composites are achieved by a wide range of inter-related factors, many of which the average enthusiast has no experience of. And just like other areas of performance, the choice of product or material can often be enhanced by the way it works hand-in-hand with others. Asking informed questions will highlight the strengths and weaknesses of a composite more

Fiber Type
High performance fibers such as carbon are lower density than glass fiber, and therefore lighter weight. Carbon fiber also offers higher tensile strength and tensile modulus (stiffness) meaning less material can be used to achieve a specific level of mechanical performance. Sophisticated reinforcing fabrics such as 'hybrids' combine the unique benefits of different fiber types into a single reinforcing more

Reinforcing Fabric
Reinforcing fibers come in many shapes and forms, from uni-directional tapes to multi-axial woven fabrics. The choice of reinforcing fabrics can optimize load bearing in a single direction or provide anistropic qualities with equal load bearing in all directions. While resin control is important in achieving a high Fiber Volume Fraction, fiber density is an equal contributor. Reinforcing fibers and woven fabrics can appear to be the same in terms of weight per square metre, however the highest performance reinforcements will feature very fine fibers as this contributes greatly to fiber density and the Fiber Volume more

Resin System
Resins have similar densities, however epoxy offers considerably higher performance than commonly used polyester resin. This means less material is required to achieve specific mechanical properties and less material results in lower more

Fiber Volume Fraction
Resin control has a big impact on the performance of a composite. The Fiber Volume Fraction measures the ratio of resin to fiber reinforcement and ideally this should be 60-70% fiber to resin by weight. An unnecessarily high percentage of resin will affect the mechanical performance and weight of a laminate. A low Fiber Volume Fraction will be apparent in heavy laminates that are not particularly strong. Manufacturing processes can greatly affect the Fiber Volume Fraction; hand lay-up and chopper gun sprayed laminates produce the worst Fiber Volume Fraction, while vacuum bagging and autoclaving consolidate laminates under pressure to achieve the highest more

Core Structure
In much the same way that post-curing epoxy resin enhances the mechanical performance of the resin matrix, core structures can add dramatically to the load bearing qualities of a laminate. Engineering principles state that doubling the thickness of a material will increase the stiffness by a factor of eight. However, all core materials are not the same. Some will achieve dramatic gains while adding marginal extra weight, while cheap materials are porous and absorb resin, thereby adding excess weight. Just because a laminate features a core structure doesn't mean it's high more

Manufacturing Process
A very wide range of manufacturing processes are used to produce FRP composites, from simple hand lay-up to sophisticated autoclaving. These processes are optimized to achieve everything from reduced component cost to high performance at any cost. Look for a manufacturing process that optimizes the Fiber Volume Fraction and promotes the mechanical performance of the resin matrix. A high Fiber Volume Fraction maximizes the mechanical properties of a laminate and minimizes the resin ratio to a practical minimum, reducing weight in the process. Consolidating laminates under pressure by vacuum bagging or autoclaving contributes greatly to composite performance. While resin such as epoxy offers much higher mechanical performance than general-purpose polyester, manufacturing processes such as oven curing, autoclaving and post-curing maximize epoxy's inherently higher mechanical more

'Voodoo Evolution™' 32 Hiboy more.

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