A straight bar of arbitrary cross section and thickness h is cold-formed to an inner radius R about an anvil as shown in the figure. Some surface at distance N having an original length L AB will remain unchanged in length after bending. This length is

The lengths of the outer and inner surfaces, after bending, are

Using Eq. (2-4), we then find the true strains to be

Tests show that |εo | = |εi |. Show that

And

Transcribed Image Text:

(R + N) LAB = LAV =- LAB