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Polycarbonate is commonly used in eye protection, as well as in other projectile-resistant viewing and lighting applications that would normally indicate the use of glass, but require much higher impact-resistance. Polycarbonate lenses also protect the eye from UV light.
Twinwall plastic most commonly refers to two exterior plastic sheets that are connected with a plastic support layer to create parallel channels. This design adds both impact toughness and the ability to support weight. Twinwall plastic may also be used to describe a pipe that has a smooth interior with exterior air filled ridges. [3]
Since carbon nanotubes have a low density for a solid of 1.3 to 1.4 g/cm 3, its specific strength of up to 48,000 kN·m·kg −1 is the best of known materials, compared to high-carbon steel's 154 kN·m·kg −1. Under excessive tensile strain, the tubes will undergo plastic deformation, which means the deformation is permanent. This ...
Eventually the stress is great enough to overcome the strain-field interactions and plastic deformation resumes. However, ductility of a work-hardened material is decreased. Ductility is the extent to which a material can undergo plastic deformation, that is, it is how far a material can be plastically deformed before fracture. A cold-worked ...
The plastic section modulus is used to calculate a cross-section's capacity to resist bending after yielding has occurred across the entire section. It is used for determining the plastic, or full moment, strength and is larger than the elastic section modulus, reflecting the section's strength beyond the elastic range. [1]
Toughness is the strength with which the material opposes rupture. One definition of material toughness is the amount of energy per unit volume that a material can absorb before rupturing. This measure of toughness is different from that used for fracture toughness, which describes the capacity of materials to resist fracture. [2]
Theoretically, the strength of a material with no dislocations will be extremely high because plastic deformation would require the breaking of many bonds simultaneously. However, at moderate dislocation density values of around 10 7 -10 9 dislocations/m 2 , the material will exhibit a significantly lower mechanical strength.
Fracture toughness varies by approximately 4 orders of magnitude across materials. Metals hold the highest values of fracture toughness. Cracks cannot easily propagate in tough materials, making metals highly resistant to cracking under stress and gives their stress–strain curve a large zone of plastic flow.