What will be oretical elongation of outside fibre in ratio to neutral axis, if inside bend radius is equal to material thickness and bending factor is equal to 0.33?

Given: 1) r = t
2) k = 0.33
Solution: Let, bend angle = ?
Length of the outside fibre= l_o =(r + t)*?
Length of the neutral axis = l_n = (r + 0.33t)* ?
Therefore, theoretical elongation = ( l_o – l_n )/ l_n
= [(r + t)*? ? (r + 0.33t)* ?]/ (r + 0.33t)* ?
As, r=t and k=0.33,
Elongation= 0.503 = 50.3%.