The modulus of resilience is the amount of energy per unit volume that a material can absorb without permanent deformation — i.e., within the elastic range. It quantifies how much energy a material can store when loaded elastically and is a key indicator of toughness for elastic loading.
This value is represented by the area under the stress-strain curve from zero to the yield point.
After the yield point, plastic deformation begins, and energy is no longer stored elastically.
Mathematically, for linearly elastic materials: \[ \text{Modulus of Resilience} = \frac{\sigma_y^2}{2E} \] where: $\sigma_y$ = yield stress $E$ = Young’s modulus of elasticity Therefore, the correct answer is the area under the stress-strain curve up to the yield point.
A steel wire of $20$ mm diameter is bent into a circular shape of $10$ m radius. If modulus of elasticity of wire is $2\times10^{5}\ \text{N/mm}^2$, then the maximum bending stress induced in wire is:
Which of the following statements are correct?
A. Malleability is the ability of a material to absorb strain energy till the elastic limit.
B. Toughness is the ability of a material to absorb energy till the rupture.
C. Resilience is the area under the load deformation curve within the elastic limit.
D. Stress-strain diagram of highly brittle material has no plastic zone.
Choose the most appropriate answer from the options given below: