Thermoplastic Wind Turbine Blades

Submitted By paddyk1234
Words: 1286
Pages: 6

Coursework 2 - MEC328 –

Thermoplastic wind turbine blades are very economical. If useless, they can be recycled, if broken they are easily repaired and especially, short mould cycle times made TPCs very attractive to blade manufacturers as they struggled to keep up with an all-time high demand. For the design of a wind turbine blade the material would most certainly have to be a thermosetting plastic, especially 30 metres in length. A thermosetting plastic, known by many as a thermoset is also a polymer. Materials like this are sometimes solid but generally liquid. Once hardened, the thermoset resin cannot be reheated and melted back to a solid. Thermoplastics are generally melted and formed in process known as moulding and extrusion. Thermoplastic and thermosetting have many similar mechanical properties although some are lost once heated.. They are very hard materials and extremely brittle. The manufacturing processes between these two plastics are almost the same. Thermosetting contain polymers that share a strong chemical bond. This, as earlier mentioned, means when shaped it cannot be melted back. Also means it is extremely hard and cannot be beaten into shape. Thermoplastics do not share the same bond and can be melted. Injection moulding is the main process to mass produce this type of product and can be seen below.

In my opinion, thermosetting would be the best choice for a 30m turbine blade. Thermoplastics are lightweight, acid resistant and extremely hard as thermosetting is heat and chemical resistant. It takes between 70 and 100 degrees to melt thermoplastics. The two have similar properties and similarities. These materials can be extremely expensive as they are built to last. Both could be used to make the blade if it came down to it, just both have advantages and disadvantages. Thermoplastics tending to be more expensive.

Car wishbones undergo a lot of pressure whilst driving so this is the first consideration to be taken on board in the manufacture. Unsprung weight is a measurement of the weight of everything outboard of the wishbones or suspension links, plus 1/2 of the weight of the wishbones or links and spring/shock. It has a great effect on handling. The diagram below demonstrates why unsprung weight is so important: The more weight outboard of the car, the more force bumps exert on the suspension (and ultimately the chassis). This force must be dealt with using springs, dampers and anti-roll bars, and the more force, the more difficult it is to keep the tire planted on the road. This is especially true of lighter weight cars. In the example above, if the car weighs 1000 lbs, a 2G bump would result in a vertical force of 10% of the car's weight. This will at the very least reduce the grip of the car, because the weight of the car is what keeps the tire planted, and pushing a car up into the air with that much force will inevitably reduce the weight on the tire, and hence grip. As the first point of contact with the road, the tires work in conjunction with the suspension geometry and weight transfer dynamics to provide grip. The grip provided by a tire is linked to the coefficient of friction (Cf) of the rubber compound and to the tire's construction (Radial/bias). This coefficient indicates the lateral grip the tire is capable of providing for a given weight being placed on it. The primary types of wheels used in racing are alloy and steel.
Features of wishbones:
Rubber to metal – a load should be applied to the bush until it pulls out of the wishbone housing. The failure load should be recorded and compared.
Rubber to metal assembly – checks should be made for the correct alignment and position of the bush within the wishbone are compared.
Mechanical Properties – Yield strength of the sheet steel on pressed steel wishbones. Tensile strength of the sheet steel used on pressed steel wishbones.
Chemical Analysis – This will ensure the materials used can