Thanks for letting us know! I've been studying and haven't found anymore major problems lately.
Thanks for letting us know! I've been studying and haven't found anymore major problems lately.
@OldSquaw and @Dr. BarberI'm certainly not a vibration expert, but the equation for transmissibilty in 2.15.3 appears to have an extra r^2 term.
Can someone check me on that?
Ah, ok. Gotcha.@OldSquaw and @Dr. Barber
I believe that the equation for transmissibilty in 2.15.3 appears is correct as it is for force transmitted due to base excitation, rather than for force applied to an oscillating mass (through, for example, rotating unbalance).
An equation that is equivalent to 60.55/60.56 from MERM13 appears on page 691 (equation 9.94) of the Fourth Edition of Mechanical Vibrations by S.S. Rao for force applied to an oscillating mass, whereas an equation that is equivalent to the equation that appears in Section 2.15.3 of the NCEES manual appears on page 241 (equation 3.74) of the Fourth Edition of Mechanical Vibrations by S.S. Rao for base excitation.
Basically both the equations in the NCESS manual and MERM13 are correct, but are used for two different methods of exciting the mass.
Hope that helps.
I have never seen those equations in such an odd form. Yikes.Section 5.2.4, the equation for fin heat transfer rate is not correct. If there is negligible heat transfer from the tip, then you use the actual fin length L, not the corrected length Lc. The corrected length is used when calculating fin heat transfer rate for a tip with convection at the tip.
Also, if you use the units for thermal conductivity as specified here, the equation needs a "12" somewhere, or better yet, the units for k should be specified as (Btu/h)/(ft F) and not as (Btu/h) in/(ft^2 F).
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Dr Barber NCEES seriously needs to pay you for single handedly fixing their screwed up reference manual.
LOLDr Barber NCEES seriously needs to pay you for single handedly fixing their screwed up reference manual.
Are you an under cover secret NCEES agent ?![]()
I know you're doing your work and working to improve @Slay the P.E.'s course content.LOL
I’m a developer of technical content for @Slay the P.E.. Re-writing all the problems so they can be solved using only the handbook has been... an adventure.
Having said that, I’m never acting in an “official” capacity when I’m snarky or when I use profanity and sarcasm![]()
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