- Compressive stress
Compressive stress is the stress applied to materials resulting in their compaction (decrease of volume). When a material is subjected to compressive stress, then this material is under compression. Usually, compressive stress applied to bars,
columns, etc. leads to shortening.
Loading a structural element or a specimen will increase the compressive stress until the reach of
compressive strength. According to the properties of the material, failure will occur as yield for materials with ductilebehaviour (most metals, some soils and plastics) or as rupture for brittle behaviour (geomaterials, cast iron, glass, etc).
In long, slender structural elements -- such as columns or
trussbars -- an increase of compressive force "F" leads to structural failuredue to bucklingat lower stress than the compressive strength.
Compressive stress has stress units (force per unit area), usually with negative values to indicate the compaction. However in
geotechnical engineering, compressive stress is represented with positive values.
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