Materials
Engineering Study Notes
1. Loads and Forces
The engineer starts the structural design process with a determination of the loads that act on the
structure. Loads can be static, dynamic, environmental, or otherwise.
Tension breaks up a member, whereas compression makes it come together.
Shear forces occur parallel to the surface, allowing for sliding between layers.
The process of bending involves both tension and compression.
Torsion turns a shaft or another object around its longitudinal axis.
2. Stress and Strain
"Stress is defined as internal force per unit area. " Strain is defined as deformation per unit length.
Normal stress: σ = F / A
Normal strain: ε = ΔL / L₀
Units for stress are Pascal, while strain does not have any units as it is a ratio.
3. Material Properties
Strength is the capacity of resisting load.
Stiffness: resistance to deformation.
Ductility: capacity for considerable deformation before fracture.
Fracture Tendency: Susceptibility to fracture without much plasticity.
Hardness: capacity to withstand energy prior to failure.