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Any follow up discussions on the dynamic analysis of foundation for vibration machines

Any follow up discussions on the dynamic analysis of foundation for vibration machines

Any follow up discussions on the dynamic analysis of foundation for vibration machines

(OP)
thread507-327848: Foundations - Vibrating Machines

I wonder why there is no follow-up on this discussion.

I have been reading the same book by Arya, O'Neil and Pincus. Same question as Egnorant had came up. Nobody seemed to have addressed it. At least not any that I can find.

In Example 2 of Chapter 6, which addresses the design of the concrete block foundation of a centrifugal machine, in Table 6-3, the calculations of Magnification facor M and Tranmissibility factor Tr used formulae for "constant force excitation" from Table 1-4. Shouldn't the formulae for "rotating mass-type excitation" be used instead? More confusingly, even though the Ms were calculated using formulae for "constant force excitation" from Table 1-4, the results for vibration amplitude Z and X came up to be matching the results of using Ms calculated through the formulae for "rotating mass-type excitation".

Another important point to be noted is that, using the numbers of Example 2 and the formulae of Table 1-4 for "rotating mass-type excitation", the Transmissibility factors are much larger than 1.0 as r = w/wn becomes much larger than 1. For example, r = w/wnv = 6949/1041 = 6.7, which gets the Trv = 11.4. That is a transmissibility factor much larger than 1.0! Does that mean the formulae for calculating the transmissibility factor of "rotating mass-type excitation" per Table 1-4 is wrong? That the formula should be the same as that for "constant force excitation"?

Some clarification would be greatly appreciated.

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