Question

The equation for natural frequency of system as suggested by Barken is __________

(a) ωn = √f(1 – r2)

(b) ωn = √cu A / m

(c) ωn = cu A / m

(d) None of the mentioned

This question was addressed to me during an online interview.

My doubt stems from Machine Foundations topic in chapter Machine Foundations of Geotechnical Engineering II

Answer 1

The correct choice is (b) ωn = √cu A / m

The explanation is: Barken suggested the following equation for the natural frequency of the system

ωn = √cu A / m

Where cu = co-efficient of elastic uniform compression of soil

A = contact area of foundation with soil

m = mass of machine plus foundation.