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Mechanical Engineering


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DrD last won the day on October 15

DrD had the most liked content!

About DrD

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  • Gender
  • Location
    Iowa, USA
  • Interests
    Kinematics, dynamics, mechanics of materials, Theory of Machines, machine design, vibrations
  • Present Company
    Machinery Dynamics Research
  • Highest Qualification
  • Engineering Qualification
    Registered Professional Engineer, TX, WI (Ret'd)

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  • Achievement /recognition/ Certifications
    Consulting work for a variety of industries, particularly in the IC engine related area (Torsional vibration analysis, shaking force analysis, engine cam design, system simulation).

    Author of several books, including one widely used textbook for Theory of Machines.

    Life Member ASME
    Member SAE
    Member SNAME

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  1. Look at the accidents that have already happened. What sort of failures led to those accidents? What sort of inspection would be required to identify the potential for those accidents before they happened? I suspect you may find a host of causes, such as 1) Metal fatigue 2) Manufacturing defects (bad welds, loose nuts, missing pins, etc) 3) Motion control problems, leading to sudden violent motions and resulting overloads Again, look at what has happened, the history, to guide your inspection procedure. DrD
  2. Automotive engineering involves both the mechanical design side and the thermal power side. Even if we narrow it just to engines, the statement above is still true. The truth is simply that you have to know both sides to some degree, even if your interest is primarily on one or the other side. DrD
  3. The term "hands-on" seems to fit, but I don't think I've ever seen the phrase "manual side." What is this last phrase intended to convey? DrD
  4. The term "steam power plant" usually refers today to an electric generating plant driven by a steam turbine supplied by a boiler. DrD
  5. Curious mix of units, some SI and some US Customary; oh, well .... What do you mean by " it holds cords at a tension between 10-60 newton meters" ? That sounds like an energy unit, not a load. DrD
  6. DrD


    Looks like a homework problem to me. Moitz, are you a graduate engineer? DrD
  7. Maybe you could start by defining MEP. When I hear those three letters, I think of Mean Effective Pressure, but I don't see a career in that. What did you have in mind?
  8. So what is the question? Do you want the tip deflection? Do you want the deflection at every point along the length? Do you want the bending moment at the anchor? What is the question? DrD
  9. The short answer is you cannot. A velocity value alone does not tell you what the acceleration is. If on the other hand you know that the displacement is sinusoidal with constant frequency, then y=A*sin(omega*t) y-dot= A*omega*cos(omega*t) y--ddtor=-A*omega^2*sin(omega*t) Your data includes say the max value of y-dot (a velocity), then you can find A*omega. From there, it is not hard to find the acceleration, all subject to the assumption of sinusoidal motion. DrD
  10. For starters, the shear modulus is a factor in determining the stiffness which in turn is a factor in determining the undamped natural frequency. Thus you should be able to work back to t he shear modulus from the natural frequency. Give it a try. DrD
  11. It appears that you are assuming that the material in the rotor remains almost centered. Why? Can it not all move to one side? DrD
  12. Perhaps we are not communicating clearly. If you want to send me a PM with a better figure and a more clear statement, I will look at your problem. DrD
  13. That's not what I would conclude, so please do not say that I said those things. DrD
  14. I'm certainly not a magnet expert, but I doubt that this is workable. Heat tends to destroy magnetism, and 2500 C is pretty hot. DrD
  15. At the levels of precision indicated by the instrument shown at your URL, you have to ask yourself if the bore is truly circular or not. DrD
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