# Cantilever

Wooden cantilever bridge that led from the hamlet of Eye over the Vispa to St. Niklaus Dorf.
The two arms of this bridge to the right and left of the central pillar are - statically speaking - cantilever arms

A cantilever beam (also: cantilever beam or cantilever ) is in the engineering mechanics (in particular in the structural analysis ) is a unilaterally mounted (in the strict sense firmly clamped ), is often the horizontal bar , the free at its end or is charged up over its entire length transversely.

As a basic system of statics , it is the idealization of a simple component (other simple static systems are the beam on two supports and the three-hinged frame ). As a beam, the length of a cantilever is significantly greater than its height and width.

The cantilever is subjected to shear , bending and sometimes torsion .

The support must be a restraint in which all six degrees of freedom are fixed. The support reactions are a bearing force and a clamping moment or - respectively decomposed into the three spatial directions - three force - and three torque components . ${\ displaystyle {\ vec {F}}}$ ${\ displaystyle {\ vec {M}}}$${\ displaystyle (F_ {x}, ~ F_ {y}, ~ F_ {z})}$${\ displaystyle (M_ {x}, ~ M_ {y}, ~ M_ {z})}$

Cantilever beam for transporting loads on a church tower ( Marienkirche in Pirna )
Cantilever in road traffic ( Marl )

The clamping torque prevents the beam from rotating around the clamping point. A bending moment acts in the beam .

A cantilever is statically determined . In mathematical terms, the clamping torque is equal to the sum of the torques of all forces acting on the carrier ( torque equilibrium ).

In the simplest case, the moment only has to absorb the dead weight of the girder. Just as easily is the case that the carrier is regarded as weightless and a force acts on the free end.

Basic functionality of a cantilever:

Voltages in a cantilever beam blank with the Kragträgerverfahren calculated.

Historically, the name comes from the extended ridge of the roof of a house to which a cable is attached to pull goods up to the upper floors.