Compression members are structural elements that are pushed together or carry a load; more technically, they are subjected only to
axial compressive forces. That is, the loads are applied on the longitudinal axis through the
centroid
In mathematics and physics, the centroid, also known as geometric center or center of figure, of a plane figure or solid figure is the arithmetic mean position of all the points in the surface of the figure. The same definition extends to any ...
of the member cross section, and the load over the cross-sectional area gives the stress on the compressed member.
In buildings,
posts and
columns are almost always compression members, as are the ''top chord'' of
truss
A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure.
In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assembl ...
es.
Description
For a compression member, such as a column, the principal stress comes mainly from
axial forces, that is forces that fall along one line, usually the centerline.
The loading capacity of a short column is determined by the strength limit of the material. The strength of a column of intermediate size is limited by its degree of inelasticity. A long column is constrained by the elastic limit (that is by the amount of
buckling
In structural engineering, buckling is the sudden change in shape ( deformation) of a structural component under load, such as the bowing of a column under compression or the wrinkling of a plate under shear. If a structure is subjected to a ...
).
See also
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Arch
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Brown truss
A Brown truss is a type of bridge truss, used in covered bridges. It is noted for its economical use of materials and is named after the inventor, Josiah Brown Jr., of Buffalo, New York, who patented it July 7, 1857, as US patent 17,722.
Descri ...
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List of structural elements Structural elements are used in structural analysis to split a complex structure into simple elements. Within a structure, an element cannot be broken down (decomposed) into parts of different kinds (e.g., beam or column).
Structural elements can ...
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Strut
A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension.
Human anatomy
Part of the functionality o ...
Notes
External links
Columns and other compression membersNumerical load numbers for reinforced concrete compression members
Columns and entablature
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