Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Search results for query: *

  1. graemew

    Checking of calculations in the aircraft industry

    Nice to see this subject on the agenda. As an Aussie, I deal with both civil and military regulators who are both quite anal about their requirement for independent verification of the adequacy of designs. I personally like to see my analyses verified. It saves grief later. I have found that the...
  2. graemew

    DC-10 tail cone placard..

    KirbyWan, Boeing have a series of standards for their placards which depends upon application. I'm sure that McD had similar. Take care to use suitable alternate materials. Remember to edge seal, and make it from really tough abrasion resistant material next time, or better train staff. "the sky...
  3. graemew

    Removing Sealant

    G'day canes0714, Sealant ain't just sealant. You will need to identify the type before a suitable dissolver can be found: Silicone?, polyurethane?, polysulphide? Is it an aircraft application?
  4. graemew

    BACN11AT16

    You might like to try the SPS website for inserts of the style you seek. http://www.spstech.com/aero/products/inserts/staked_inserts.html If you give them the Boeing pn tehey may well be able to provide a suitable alternate. You will probably need to seek an independant approval for it though...
  5. graemew

    Cable chafing through a fairlead.

    G'day thruthefence, The requirement in the FAR's is for Controls, and a system that locks/unlocks a tailwheel is a control. If it was certified with a cable rubbing where it shouldn't, it points to an inadequate certification process. The first person to touch it will be duty bound to fix it and...
  6. graemew

    Cable chafing through a fairlead.

    G'day Foglights and Wil I'll add my little bit if I may. Will you are quite correct in what you say and if Foglight looks in FAR27.685 he will see the following (extract) (a) Each detail of each control system must be designed to prevent jamming, chafing, and interference from cargo...
  7. graemew

    high voltage generation system

    G'day Karl You need a list of requirements to fill out before you can get started: 1. Certification basis for compliance purposes 2. Power characteristics: 2.1 Duty cycle, 2.2 Power requirement (watts) 2.3 Voltage input, voltage AC or DC 2.4 Voltage output, voltage AC or DC If AC, single phase...
  8. graemew

    Wet Rivet Shear Strength

    wktayor G'day Wil Loctite advise that: "The Primers concerned have copper salts (in minute quantities) to serve to accelerate the polymerisation (curing) process of the anaerobic. Primers are used in circumstances such as: inactive metals (eg Stainless Steel etc) need to reduce cure time...
  9. graemew

    Wet Rivet Shear Strength

    G'day rb1957: I confess that I agree with you about wanting a bit more info.about CSK fillers. I also have called them up for use, and unlike the experience of others, mostly they have been used. Maybe because I "hover around" at times and they are afraid that I will catch them leaving them...
  10. graemew

    Help on Stress Analysis Distance Learning Course

    G'day mate, Like many areas of endevour, academic quals. will only take you so far. The Flabel course is a good one on practical stress analysis but it will still only give you the basics. Yes, it is basically what is in the book. You will need to get out there and apply the lessons in a...
  11. graemew

    Pitch Distance

    G'day Istambul As 737eng says, changing the pitching of fasteners in a fitting can vary the load distribution between the fasteners, as well as the reactions to applied loads which may have a component parallel to, but displaced away from the mating surfaces. Without knowing what the fitting...
  12. graemew

    Wet Rivet Shear Strength

    Gooday Wil Thanks for the response, The issue is with the Loctite Primer. It gets sprayed on quite liberally at times and sometimes is not adequately washed off afterwards (it is solvent based and I have seen procedures not calling for a wash afterwards). You are correct in regard to isolation...
  13. graemew

    Wet Rivet Shear Strength

    G'day Wil A caution on the use of Loctite primers. I was advised by a Loctite rep. some years ago that these contain a very fine dispersion of copper or iron (depending on the primer type)to catalyse the adhesive, which should be washed off after the Loctite has set. My experience of the use of...
  14. graemew

    Inter-rivet buckling

    A complicated subject with an empirical base, connected to effective sheet widths. See Bruhn Section C7.12 to C7-20 for discourse. Fir is elastic, wrinkling is plastic. With staggered rows, use the lengthwise spacing of each row to calculate Fir for each row unless the 1/2W calculated from the...
  15. graemew

    panel post buckled capacity

    Uniaxial compression with a superimposed shear is wing torsion box upper skin stuff. Provided that the panel is bounded by stiffeners (aka stringers and ribs) the panel will carry substantial shear even though the onset of buckling may occur at relatively low stress. The mix of shear and...
  16. graemew

    Question on the definition of Limit Load and service life

    Some interesting views expressed here, not all of which I could agree with. All repairs on large aircraft should comply with FAR25.601 "The airplane may not have design features or details that experience has shown to be hazardous or unreliable. The suitability of each questionable design detail...
  17. graemew

    beam plastic bending / "drinking straw" failure?

    Good on you. I am pleased that you are now viewing this in the correct light. Here was me thinking that you were dealing with a bit of light structure. All the best with it.
  18. graemew

    Matrial Bearing vs Compressive Yield Stress

    You are on the correct path, but please remeber that the values in MIL-HDBK-5H are "dry-pin" values which normally require a knock-down factor in the real world. Also the fit of the pin in the hole will impact upon your bearing allowable as well. The larger the hole/pin clearance, the lower the...
  19. graemew

    ForceTec Rivetless Nutplates

    Gooday utspg 1980 and Wil, I have looked at the Forcetec nutplate a numner of times in the past for resolution of a number of problems but the biggest issue has always been the closeness of the anchor nut rivet holes. According to Len Reid at FTI, it is necessary to cold work those as well...
  20. graemew

    beam plastic bending / "drinking straw" failure?

    Yes it is. The equations and pictures in Bruhn do not illustrate this very well but the peaky discontinuities in the Kc curves are related to the number of waves in a panel. Also, elastic buckling isn't a "failure" per se. It can become a limiting stress since a buckled part will not carry a...
Back
Top