Question

The stress induced in an extra full length leaf in case of a prestresed leaf spring is

(a) 1.5 times that in graduated leaves

(b) equal to that in graduated leaves

(c) dependent on the ratio of the number of extra full length and graduated leaves

(d) none of the mentioned

This question was posed to me in unit test.

I'd like to ask this question from Closely-coiled Helical Spring and Compound Pendulum in portion Simple Harmonic Motion of Machine Kinematics

Answer 1

Right option is (b) equal to that in graduated leaves

To explain: The leaves which are cut from original triangular leaf, are termed as graduated leaves. In actual practice some extra leaves with the same length as that of top leaf are added to increase the stiffness of the spring.