Material Properties
- Strength: Resistance to deformation. Tensile = being pulled apart. Compressive = being crushed.
- Elasticity: Returns to original shape after deformation (rubber, steel springs).
- Plastic deformation: Permanent deformation that does not return.
- Brittle: Breaks without significant deformation (glass, cast iron).
- Ductile: Can be drawn into wire without breaking (copper, gold).
- Malleable: Can be hammered flat without cracking (gold, aluminum).
- Hardness: Resistance to scratching or indentation.
- Density: Mass per unit volume (kg/m³).
Structural forces: - Tension: Pulling/stretching force (suspension bridge cables, ropes). - Compression: Pushing/squeezing force (columns, arches). - Shear: Layers sliding past each other (scissors cutting, bolt being sheared off).