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Recent content by paulmech01

  1. paulmech01

    Minimum Fibreglass Tube Engagement

    How do I calculate the, Hoop stress: 1. In the aluminium tube? 2. In the Fibreglass tube?
  2. paulmech01

    Minimum Fibreglass Tube Engagement

    For pressure I have used: =(0.5xDensityAir)xVdes2xCfig =(0.5 x 1.2kg/m3) x 66.66^2 x 1.2 =3199.36Pa Multiplied by Area Gives a Force(N): Area 76.5 x 5500mm = 0.421 m2 Area x Pressure = 1346.93 N Is this not correct?
  3. paulmech01

    Minimum Fibreglass Tube Engagement

    To answer some questions. Orientation is vertical. Target Wind Speed is 240 km/h Fixed into aluminium 6061 using a silicone adhesive. Fibreglass tube is pultruded matting in polyester matrix. Wind Speed: 240 kmh, 66.67 m/s Wind Pressure: (0.6x(Vel2)x1.2) = 3200.00 Pa Fibreglass Projected Area...
  4. paulmech01

    Minimum Fibreglass Tube Engagement

    The Fibreglass tube is sleeved into the aluminium tube. The fibreglass is quite long (about 5-6m) out of the aluminium tube in a cantilever situation, and has a load due to wind acting upon it. This generates a bending moment down at the connection into the aluminium tube. My question is how...
  5. paulmech01

    Minimum Fibreglass Tube Engagement

    What is the minimum Tube Engagement that is necessary for a connection between a Fibreglass Tube into an aluminium tube that is in cantilever. Fibreglass tube is 76.5mm OD 6mm Wall Aluminium Tube is 77.0 ID 6mm wall
  6. paulmech01

    Electrical Connection to aluminium substrate

    Is this just a consumables site. What product do you mean exactly, the Super Alloy 1? What is its composition, (ie silver, tin)? What is the flux used with it made from?
  7. paulmech01

    Electrical Connection to aluminium substrate

    I am trying to make an electrical connection between an electrical cable and aluminium, currently brass pins are soldered to the aluminium and the wire is soldered to the pin. We need to move away from the solder used to join the brass pin to the aluminium as it contains lead, but no ther lead...
  8. paulmech01

    Electrical connection to Aluminium Subtrate

    The core of the cable that is connected to the aluminium is tinned copper. Could this be spot welded or induction or some other resistance weld joined to the aluminium. The aluminuim is quite thin, Dia 12mm x 1mm wall.
  9. paulmech01

    Electrical connection to Aluminium Subtrate

    I am trying to make an electrical connection between an electrical cable and aluminium, currently brass pins are soldered to the aluminium and the wire is soldered to the pin. We need to move away from the solder used to join the brass pin to the aluminium as it contains lead, but no ther lead...
  10. paulmech01

    19mm Dia x 720mm Fibreglass Tube Natural Frequency

    Thanks Steve, I have just borrowed Thompsons, Theory of Vibration, I think I really do need a text on this topic. The result looks good, I'll make sure it all seems Ok then I will get back to you guys with result.
  11. paulmech01

    19mm Dia x 720mm Fibreglass Tube Natural Frequency

    Thank Tom, that's handy. Is this working on the same theory that we have been discussing. ie. Per Den Hartog's Mechanical vibrations wn = a * sqrt(E*I/(mu*l^4) also is this formula correct for calculating the vortex shedding frequency for a closed end circular hollow section dia 16mm x 720mm...
  12. paulmech01

    19mm Dia x 720mm Fibreglass Tube Natural Frequency

    I have plugged all these into an excel spreadsheet and I am now playing around with units metric/imperial. Youngs modulus of E= 30000Mpa converts to 4351132lbs/in2. I have corrected to rod OD to 16mm ID 14mm Which has an I = 1328.9 metric = 0.00319 imperial Density of 1663kg/m^3 = 0.06007969...
  13. paulmech01

    19mm Dia x 720mm Fibreglass Tube Natural Frequency

    The material is a prepreg E-Glass. E = 30000 Mpa Density = 1663 kg/m3 Not sure how this equates to a Linear density in lbs/in
  14. paulmech01

    19mm Dia x 720mm Fibreglass Tube Natural Frequency

    The tube is closed at both ends. The angle of the airflow can change depending on where this is mounted. Position a = perpendicular flow. Position b = 45deg up from perpendicular.

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