Materials are frequently chosen for various applications because they have desirable combinations of mechanical characteristics. For structural applications, material properties are crucial and engineers must take them into account. The mechanical behavior of a material reflects its response or deformation in relation to an applied load or force. Key mechanical design properties are:
- Stiffness. Stiffness is the ability of an object to resist deformation in response to an applied force.
- Strength. Strength is the ability of a material to resist deformation.
- Hardness. Hardness is the ability to withstand surface indentation and scratching.
- Ductility. Ductility is the ability of a material to deform under tensile load (% elongation).
- Toughness. Toughness is the ability of a material to absorb energy (or withstand shock) and plastically deform without fracturing (or rupturing); a material’s resistance to fracture when stressed; combination of strength and plasticity
- Malleability. Malleability is the ability of the material to be flattened into thin sheets under applications of heavy compressive forces without cracking by hot or cold working means.
- Creep. Creep is the slow and gradual deformation of an object with respect to time.