Lesson 6: Bending Stress and Strain

Question 1

What is stress?

Answer 1

Stress is force per unit area within a material:
σ= A/F

Where:

𝜎= Stress (Pa or N/m²)
𝐹= Force (N)
𝐴= Cross-sectional area (m²)

Question 2

What is strain?

Answer 2

Strain is the measure of deformation in a material due to applied stress:

ε= ΔL/L0
​

Where:

𝜀= Strain (dimensionless)
Δ𝐿= Change in length (m)
𝐿0= Original length (m)

Question 3

What is the flexure formula for bending stress?

Answer 3

σ= My/I

​Where:

𝜎= Bending stress (Pa)
𝑀= Bending moment (Nm)
𝑦= Distance from neutral axis (m)
𝐼= Moment of inertia (m⁴)