Content Pages1. The Objectives of this Project 2

2. The Objectives of this Meeting 3

3. The Different Ideas Explained (4-10)a) Diffraction 4-5b) Resistance Measurement technique 6-9c) Natural frequency measurement 10

4. Considerations to stress 11

5. Conclusion 12

Carbon Fibre Wire Quality Measurer

1. The Objectives of this Project3 Objectives1. Main Objective – Verify Wire quality before it is assembled to Fast Wire Scanner

What Influences Wire Quality? – This needs discussion: Local and Average Diameter, Longitudinal and Transverse Wire Cracks, Roundness…

PS Wire Specifications: 12 strands of 7 micron Carbon Fibre with 10 turns over a length of 200mm.

2. Second Objective: Measure Individual Strands of Carbon Fibre

3. Third Objective: Measure Wire when the Fast Wire Scanner is in the Machines

2. The Objectives of the Meeting1. What am I doing

2. What Ideas does everyone have

3. What does everyone thinks makes a Wire good enough

• Local and Average Diameter, Cracks and Roundness can be measured with the techniques

4. What Ideas should I go forward with

3. The Different Ideas explained

a. Diffraction:Brief Theory: 1. Point a laser with a wavelength within an order of the diameter of the wire and get the pattern shown in

the image.

2. Measure the spacing between the red marks on the pattern

3. Measure the distance between the Laser Generator and Wire

4. Therefore diameter can be calculated with above equation:• d = Diameter of wire, • λ = Wavelength of laser,• D is distance of laser generator to wire and • w is the spacing between the centre of the red marks in the picture above.

Two companies who use the diffraction technique and how it is useful for quality analysis:CERSA: Their machines can measure the quality of individual strands of fibres and potentially the whole wire.

Aeroel: Their machines can measure quality of whole wire but not individual strands since they can not measure down to 7 Microns thing

An anomaly in the roundness, diameter or if there is a blister or crack will get amplified as shown on the left

This Companies machine can measure small Blister like flaws as shown in the image

1. I have focused on two companies which measure beyond its diameter

2. I am also in contact with these companies

b. Resistance Measurement Technique

• Resistance is Measured and Compared with theoretical resistance:

• Theoretical Resistance; as seen in the equation: Resistance = (Resistivity × Length)/Area

• Resistivity varies with temperature, Length and cross sectional area and are known therefore resistance is calculated.

• We have 12 wires, so when these are put in parallel the total resistance becomes 1/12 of the one strand resistance.

• Therefore this total resistance can be calculated and compared with measured resistance.

Different methods for Measuring Resistance• We Currently have a method installed on the Fast Wire Scanners; which

can be monitored online.

The following methods are:

• Wheatstone Bridge

• Voltage Divider

• EIS(Electrochemical Impedance Spectroscopy)

• Fast Wire Scanner existing method ( I do not know circuitry for this)

Resistance Methods•Wheatstone Bridge:

Advantage: • Uncertainty only from resistor values since voltages are in balanceDisadvantage: • Several circuits required if you measure reactance as well

• Voltage DividerAdvantage: • Simple CircuitryDisadvantage: • Uncertainty in both measured value and components used

• EIS(Electrochemical Impedance Spectroscopy)Advantage:

• Uncertainty only in measured value

Disadvantage:

• Requires particular machines

• Fast Wire Scanners existing methodAdvantages:

1. It is already installed

2. We have results from it to show us what the method can do

3. The measurements can be monitored online whilst machine is installed.

Disadvantage:

• I do not know how it works

c. Natural Frequency Measurement•Method:• Get Wire to vibrate at its Natural Frequency

•Measure this value

• Compare this value with theoretical

• Use these results to analyse potential damage.

• This has been done to analyse damage before; however not for Wires as thin as these, hence I doubt this method will be feasible or better than the other methods.

1. Our Supplier of the Wire: Goodfellows-Mitsibushi(MRC):

a) The Carbon Fibre we get currently for our wire scanners is from Good fellows has a diameter tolerance of +-25%, which may have been a cause for previous wire failures, or could be insignificant.

b)I have contacted Goodfellows; their supplier of Carbon Fibre is Mitsibushi; who have given me the details of their Carbon Fibre.

c)Whether the 7 Micron wire is the best for the Fast Wire Scanners is under debate; therefore I have not looked into other suppliers of the wire yet.

2. What is it we are really looking to measure in the wire?

4. Considerations To Stress

5. Conclusions• Measure Individual Carbon Fibre Strands with Cersa’s Laser Diffraction

Sensor 14.0 machine.

• Measure The PS Wire with either Cersa’s LDS 14.0 Or Aeroil XLS13XY/1500/B Sensor

• Monitor the quality of the PS wire with the resistance measurement system already installed on the Fast Wire Scanners inside the machines.

• Consider new suppliers and look into significance of this large tolerance.