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  1. midsidenode

    phosphoric acid anodizing

    Thanks Dave another question for you: would you say that a phosphoric acid anodized coating is "conductive"?
  2. midsidenode

    phosphoric acid anodizing

    I'm not at all familiar with phosphoric acid anodizing, but apparently, I'm going to need it as a final process for surface preparations involving adhesive bonding. The problem is that I neither need it nor want it in other areas that do not involve bonding - it obviously involves dipping the...
  3. midsidenode

    static loads and 3Sigma Loads

    Thanks for the reply rb1957. The PSD is not associated with gust - it's vibration. The static loads established from aero and inertia were ultimate loads.
  4. midsidenode

    static loads and 3Sigma Loads

    Have you ever seen someone add static load results to 3Sigma loads? In other words….say I exposed a structure to some aerodynamic and inertial loads and then obtained resulting fastener loads. Then I exposed the same structure to a power spectral density curve and obtained resulting fastener...
  5. midsidenode

    FEMAP PSD Anslysis

    I was wondering if someone could give me some free FEMAP tech support as my access to Siemens has lapsed. The question goes like this: I can successfully complete a solve for a laminate structure’s normal modes (#2 Normal Modes/Eigen Value), followed by a solve for the modal frequencies (#4...
  6. midsidenode

    equivalent pressure

    Yes - it's indeed air and a very violent environment. The overall sound pressure level (OASPL) for the frequency spectrum is 164.2 dB. How is the OASPL value calculated using the data of the frequency spectrum? thanks Greg.
  7. midsidenode

    equivalent pressure

    Thank you Greg. I am reading this report and it says that 144.6 dB at 400 Hz converts to an equivalent 3-sigma pressure of 2.11 psi. That doesn't seem correct. Thoughts? v/r, msn
  8. midsidenode

    equivalent pressure

    I am not well versed in acoustics so bear with me...... I am reading a report that presents an acoustic noise chart whereby a range of 1/3 octave sound pressure vs a frequency range is plotted. The report states a "worst case" value (dB) at a specific frequency and goes on to say that this can...
  9. midsidenode

    Film Adhesive - Supported vs Unsupported

    Are random carriers generally less expensive than kit? I will plan on talking to the supplier. Thanks SW.
  10. midsidenode

    Film Adhesive - Supported vs Unsupported

    Something that I've never had a good grasp on was how to determine when I would need a supported or un-supported film adhesive. Is the carrier only used to maintain a consistent bondline thickness? When should one choose a knit vs random carrier? thanks, msn
  11. midsidenode

    Resin properties following a cure

    Yes, you guys are correct. There is always usually some darkening. It just seems a little excessive this time. I want to be able to prove to my customer (and to some extent- myself) that all is still well. I think the idea of just creating some panels with proper thicknesses for SBS and varying...
  12. midsidenode

    Resin properties following a cure

    SW, The resin is cyanate ester so you can imagine what kind of an item i'm dealing with here. The production cure temp is 350F with a 400F post cure. The repair cure temp was 350F with no post cure - only 90 minutes. The area around the repair looks to be on the verge of charring. I've worked...
  13. midsidenode

    Resin properties following a cure

    I agree that the act of bonding doublers to the specimens and thinking that the skin will experience interlaminar failure during a test is kind of a pipe dream. I'm not sure it's even work attempting. I do have access to every type of Tg testing nevertheless, I do not see how I can use Tg to...
  14. midsidenode

    Resin properties following a cure

    SW, I should have clarified my intentions a little better. I'm looking at this from a strength perspective. I have a repair that must be carried out on some skin. The repair was performed remotely using a portable hot bonder unit. The person that performed the repair assures me that the proper...
  15. midsidenode

    Resin properties following a cure

    Does anyone know of an acceptable test for evaluating resin properties of a laminate after a cure? I was thinking of probably using ASTM D2344 (short beam, interlaminar shear) but my problem is that the laminate has a cured ply thickness of only .025 inches. This is well below the parameters...
  16. midsidenode

    FEMAP Material Card

    Thank you rb. what about Poisson's - something very small and non-zero - or other? v/r, msn
  17. midsidenode

    FEMAP Material Card

    A question for any FEMAP users. My FEM will require a material card for a film adhesive. The properties that I have for the film adhesive are shear modulus, strain at failure and maximum shear stress. What would be the best material card to use for this material? I would call TECs but it has...
  18. midsidenode

    additive manufactured part is corroding

    First of all, thanks to you both for your replies. Porosity was what I expected as I have seen things like this happen when beryllium copper was plated with gold without an intermediate plating of something such as nickel. Ed - there was no special operation to smooth or seal the Ultem before...
  19. midsidenode

    additive manufactured part is corroding

    We made a part from ULTEM 9085 using additive manufacturing and then electroplated it with copper. It didn't take long for the darn thing to start corroding. Does anybody know what the heck is happening?
  20. midsidenode

    curve conversion

    Thank alot Tom. and thank you Brian for that info as well.

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