Page 79 - Fundamental Of Design In Mechanical Engineering

Deformation under direct axial loading

◦ Deformation

1. Deform Uniformly –
L represent the axial strain

undeformed every where in the bar.
O . . A
the axial strain is the
same at all point
x Δx

L + 2. Deform not Uniformly –
d
Δ
=
deformed ε = lim Δx dx
O . . A Δx→0

Δx + Δ elongation bar

=׬ = ׬ εdx
0 0
◦ Compressive (shortening) carries a negative sign (example
Є=-0.001) 79