In
solid mechanics, a point along a
beam under a lateral
load
Load or LOAD may refer to:
Aeronautics and transportation
*Load factor (aeronautics), the ratio of the lift of an aircraft to its weight
*Passenger load factor, the ratio of revenue passenger miles to available seat miles of a particular transpo ...
is known as a point of contraflexure if the
bending moment about the point equals zero.
In a
bending moment diagram, it is the point at which the bending moment curve intersects with the zero line (i.e. where the bending moment reverses direction along the beam). Knowing the place of the contraflexure is especially useful when designing
reinforced concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having hig ...
or
structural steel
Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a profile of a specific cross section. Structural steel shapes, sizes, ...
beams and also for designing bridges.
Flexural reinforcement may be reduced at this point. However, to omit reinforcement at the point of contraflexure entirely is inadvisable as the actual location is unlikely to realistically be defined with confidence. Additionally, an adequate quantity of reinforcement should extend beyond the point of contraflexure to develop bond strength and to facilitate shear force transfer.
See also
*
Deformation
*
Engineering mechanics
*
Flexural rigidity
*
Flexural stress
*
Fluid mechanics
*
Inflection point
*
Strength of materials
References
Solid mechanics
{{Engineering-stub