Mechanical Engineering - Strength of Materials - Discussion

Heat causes the expansion, hence there is no support to restrict the expansion. Therefore no resistance, no stress induction.

When heating a body tensile stress will be indicated.

Stress = thermal coefficient x change in temperature x modulus of elasticity.

Stress depending on temperature, s = alpha * t * e.
But here not constrained so no stress.

The body is free to expand so no stress.

As there is no obstruction and the bar is free, no stress will be induced.

There is no stress develop, because when we heated a metal then it receive the heat energy and the molecules nearer to it produce vibration and transfer the thermal energy to other.

This causes the rise in its temperature and as well as increases the intermolecular distances as there is no external forces applied on the metal who the metal resists it, and as we know that stress is restoring force per unit crossectional area so there is no stress developed in the material.

Only the thermal stress come in the picture.

There is no restriction in expansion so no stress will generated.

A free bar never had any stress. Its a fact.

It will induce thermal stress.