A weight (W)is dropped from a height (y) upon the cantilever beam in Fig. P7.17 causing a permanent deformation (δ), where δ is a function of h, b, ﻠ, and σf
in addition to W and y (where σf
is the plastic flow stress of the beam material). Thus, before dimensional analysis:
δ = ψ3
(W, y, h, b, ﻠ, σf)
However, further reflection reveals that in place of W and y, the energy of impact (U = Wy) may be used, and instead of h and b, the moment of inertia about the neutral axis (IN) = 1/12 bh3
[in.4] may be employed. Starting over:
δ = ψ3
(U, IN, ﻠ, σf)
a) Perform a dimensional analysis.
b) When a 1:10 scale model test is performed under geometrically similar conditions where σp/σm
= 2, it is found that when Um = 10 in. lbs, δm
= 0.1 inch. Find the corresponding values of Up and δp.