Question

What does it mean, if the stress-strain curve is linear for a material?
1. The material follows Hook's Law
2. The material follows Pressure law
3. The material follows deformation law
4. None of the above is correct

Answer 1

Correct Answer - Option 1 : The material follows Hook's Law

CONCEPT:

• Stress-Strain Curve determines how a material behaves how it has a relationship between the strain and stress for a given material.
  • We apply a force on a material cylinder and record the change in length at various applied forces to cause the strain.

• Hook's Law: For small deformations, the stress is proportional to the strain produced. 

Stress ∝ strain

stress = k × strain

where k is the proportionality constant.

EXPLANATION:

• According to Hook's law

stress = k × strain

• It is the same as the straight line y = mx.
• Stress is on the y-axis, strain is at the x-axis, and k is slope m.
• So straight line on a stress-strain curve represents that material is following Hook's law.
• Hence the correct answer is option 1.