Compression members are structural elements that are pushed together or carry a load; more technically, they are subjected only to
axial
Axial may refer to:
* one of the anatomical directions describing relationships in an animal body
* In geometry:
:* a geometric term of location
:* an axis of rotation
* In chemistry, referring to an axial bond
* a type of modal frame, in music
* ...
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
column
A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member ...
s 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 assembla ...
es.
Description
For a compression member, such as a column, the principal stress comes mainly from
axial
Axial may refer to:
* one of the anatomical directions describing relationships in an animal body
* In geometry:
:* a geometric term of location
:* an axis of rotation
* In chemistry, referring to an axial bond
* a type of modal frame, in music
* ...
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
*
Arch
An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it.
Arches may be synonymous with vau ...
*
Brown truss
*
List of structural elements
*
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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