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  1. scotland6

    FE modelling of a peltier (TEC)

    Hi, I am creating a FE model of a heat source cooled using a pelter mounted to a copper block then to a heatsink. I am wondering on how to represent the characteristics of the peltier in steady state then a transient model. I am assuming the hot side of the peltier is at 50°C with a deltaT of...
  2. scotland6

    Welding of SHS to I Beam End-to-End

    Hi Guys, Please see attached picture of the frame. Its a 30ft ISO frame 8f x 8ft and it carried a large pressure vessel. I have a requirement to remove as much wight as possible hence the joint. The moment acting on the connection will be minimal but I want get the specifics right for...
  3. scotland6

    Welding of SHS to I Beam End-to-End

    Hi Guys, I wish to weld a 250mm SHS with an internal flush end cap to a 200HEB I beam. The combined beam will be horizontal and the bottom of the SHS will align with the bottom flange of the I beam, see attached. The connection will be subject to bending forces, not yet established. Is it...
  4. scotland6

    hydraulic simulation software

    Hi, Can anyone recommend a good hydraulic simulation package? Even any free on web would be helpfull. Regards
  5. scotland6

    Damping Constant

    Hi, Sorry didn't know the piston velocity initially but determined it by testing. Can c be calculated without knowing velocity at this stage? Scotland6
  6. scotland6

    Damping Constant

    Hi, Can someone help me work out the damping constant of a cylindrical viscous damper. I know the viscosity of the oil, the ID of the tube, the OD of the piston and its velocity. The oil is effectivly being forces through an annular area from one side of the piston to the next. Any help...
  7. scotland6

    Vibration Isolation

    Hi Greg, But I don't know k or wn I only know m. I have worked out the velocity change due to the 1/2 sine input. Can I use this to establish wn? Sorry for labouring this. Regards Scotland6
  8. scotland6

    Vibration Isolation

    Thanks Greg for this. Can you expand? I have the following variables to set up the ODEs for a single-degree-of-freedom system :- m is mass (known) c is damping coefficient (unknown) k is spring (mount) stiffness (unknown) y1 is displacement of the mass (unknown) y2 is input displacement...
  9. scotland6

    Vibration Isolation

    Hi, Hopefully someone can give me some assistance. I have a mass that I wish to isolate with 4-off AV mounts. The mass (40kg) is subject to a 1/2 sine input of 30g 18ms. The isolators I have in mind have a 'Q' of 5. How can I calculate the velocity due to the shock, the natural frequency of...
  10. scotland6

    Random Vibration Help

    I have a stepped random vibration PSD profile going from 20Hz to 2000Hz (4.2 grms). If I know the mass, stiffness, etc how can I calculate the max acceleration and displacement. I think it uses convolution integrals but I require some help to understand it. Any help would be appreciated...
  11. scotland6

    Random Vibration Calculations

    I have a stepped random vibration PSD profile going from 20Hz to 2000Hz (4.2 grms). I have a suspended mass of about 5kg on 4 off AV mounts. Can anyone give me an idea of how to select the mounts or caclulate the response given that the frequency of the suspended mass has to be approx. 40Hz? I...
  12. scotland6

    Anti Vibration Mounting

    Can anyone provide me with any good site references for how to mount electronic assemblies using rubber AV mounts? What consideration are required, i.e. C of G position, etc. I have to design to withstand random vibration and shock loading in 3 axes. Any help would be appreciated.
  13. scotland6

    Shuttle Disaster

    I don't know exactly how or if they relate to each other but when designing for a shock load, specifically a half sine pulse, the safest approach for a dynamic system is to double the static load. This is a cover all and the actual amplification factor depends on the system natural frequency...
  14. scotland6

    Shuttle Disaster

    JimMetalsCeramics, Without putting you to too much bother can I get a copy also? I am at scotland6@bigfoot.com. Regards John
  15. scotland6

    Material Properties

    Can anyone halp me collate a material properties database? I am looking for web links, book or paper references etc. on aluminium alloys, stainless steels, carbon steels, copper, brass, phosphor bronze, nickel aluminium bronze, rubber (natural,chloroprene, etc) and foam (expanded neoprene...
  16. scotland6

    looking for "simple" plate design software

    RG88's thoughts are well founded. As glass is a brittle material it will have a distribution in fracture strengths normally described by a Weibull distribution. This distribution is based on sample testing of representative samples with representative loading and the spread of failure...
  17. scotland6

    3D Scanning

    Try http://www.3dscanners.com/ for some possible assistance.
  18. scotland6

    Fracture Mechanics

    Does anyone have any good liks to sites that deal with flaws / cracks in pressure vessels subject to cyclic pressure loading? Anything that relates to Paris equation and the likes? Regards Scotland6
  19. scotland6

    Weld Repair of Super Duplex Steel

    Can anyone possibly give me some details, or links to others sites, on how to weld repair super duplex specifically F55 (S32760)? I would appreciate any assistance with this. Regards Scotland6
  20. scotland6

    Heat Removal

    Can anyone help me?? I am trying to evaluate the size of hole (diameter and length) that I need to remove one Watt of heat from an aluminium component. This requirement is for general cooling of a component with heat loads contained within as aluminium alloy has good thermal conductivity. If...
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