Mechanical Design 2 min
Stress vs Strain: Why Steel Bends Before It Breaks
Pull a steel bar and plot force against stretch. The curve has a straight part, a yield point, a long plastic region and a final neck and break. Every number a designer uses comes from it: modulus, yield strength, ultimate strength, ductility.
The video runs the test on steel and on a brittle material, and shows what each feature of the curve means for a real part.
In this video
- Elastic region and Young's modulus
- Yield strength and the 0.2 % offset
- Plastic deformation, necking and fracture
- Ductile versus brittle materials