Thermal stress in a composite bar DOES NOT depend on which of the following factors?

Explanation:

Thermal Stress in Composite Bars

• Thermal stress refers to the stress induced in a material or structure due to a change in temperature. When a composite bar (a bar made up of two or more different materials) is subjected to a temperature change, each material tends to expand or contract based on its coefficient of thermal expansion. However, since the materials are bonded together, they restrict each other's free expansion or contraction, leading to thermal stress.
• In the context of composite bars, thermal stress depends on several factors, including the coefficient of thermal expansion, temperature change, modulus of elasticity, and the way materials are bonded. However, thermal stress DOES NOT depend on the area of the cross-section of the composite bar.

The formula for thermal stress is given as:

σ = E × α × ΔT

Where:

• σ: Thermal stress
• E: Modulus of elasticity
• α: Coefficient of thermal expansion
• ΔT: Temperature change

From the formula, it is clear that the thermal stress does not depend on the area of the cross-section. While the area of the cross-section may influence the total force generated due to the thermal stress (as force is given by stress × area), the stress itself remains independent of the cross-sectional area.