Questions
1) Carbon Fibres are manufactured from one of three pre-cursors Polyacrylonitrile (PAN), Pitch or Rayon. With the aid of diagrams explain:
a) The process of manufacture of carbon fibres from each of the three pre-cursors.
b) The advantages and disadvantages of using each pre-cursor for manufacturing carbon fibres.
2) Explain the strengths and limitations of thermosetting and thermoplastic resins in a composite material. Refer to specific resins in your answer and include specific applications.
3) Explain the following composite manufacturing processes:
a) Resin Transfer Moulding (RTM).
b) Spray Lay-up.
c) Autoclave Moulding with Vacuum Bag.
For each process include a diagram, description of the process, applications, tools and equipment and the health and safety issues that relate to each process.
4) With the aid of diagrams explain the procedures used and detail the health and safety precautions associated with the following types of repair:
a) Patch repair.
b) Scarf repair.
c) Step sanded repair.
5) A Carbon Fibre Reinforce Polymer (CFRP) has the following properties:
E11 = 200.00 GPa, E22 = 11.10 GPa, G12 = 8.35 GPa, ν12 = 0.32
a) Calculate the minor Poissons ratio ν21.
b) Calculate the Compliance Matrix.
c) Calculate the Stiffness Matrix
6) Lamina from Q5 is rotated through 45° and subjected to the stresses shown in the diagram below. Note that both the vertical direct stress and shear stress are acting in the negative sense according to convention.
a) Calculate the Transformation Matrix and modified Stiffness Matrix.
b) Calculate the Inverse Transformation Matrix and modified Compliance Matrix.
c) Calculate the stresses in the 1-2 directions.
d) Calculate the strains in the 1-2 directions.
e) Calculate the strains in the x-y directions.
7) With the aid of diagrams identify and state the cause of the four defects associated with composite material structures listed below:
a) Delamination
b) Disbond
c) Void
d) Contamination.
8) With the aid of diagrams describe the procedure and explain a use for the tap test, ultrasonic, thermographic and radiographic inspections of composite material structures and components.
Quality of arguments supporting these claims, evaluation, analysis, report presentation, references and bibliography.