Mechanical Stress

Mechanical stress is the internal resistance offered by a unit area of a material to an externally applied load.

Types of stress:

• Normal stress – $\sigma$
  • Tension (positive)
  • Compression (negative)
• Tangential shear stress – $\tau$

SI units are Newtons per square meter – $1\text{ N}/{\text{m}}^2=1\text{ Pa}$ US units are pounds per square inch – $\text{psi}$

Types:

• Normal Stress
• Direct Shear Stress
• Pure Shear Stress