- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 27 Oct 2020
Point of contraflexure
|The point of contraflexure (PoC) occurs where bending is zero and at the point of change between positive and negative (or between compression and tension).|
In a beam that is flexing (or bending), the point where there is zero bending moment is called the point of contraflexure. At that point, the direction of bending changes its sign from positive to negative or from negative to positive. (It may also be thought of as a change from compression to tension or vice versa).
An analogy may be made with a speeding train travelling west on a single track. In order to reverse direction and travel east, it must decelerate, stop then accelerate in the opposite direction. The point it stops, even if momentary, is zero – the neutral point, where it is not travelling.
Theoretically, when considering a structural member under load, such as a reinforced concrete beam, the point of zero bending moment would seem to suggest no reinforcement would be required. However, omitting reinforcement at that point is considered inadvisable as, in a real-life situation, it may be difficult to locate the exact point of contraflexure.
 Related articles on Designing Buildings Wiki
Featured articles and news
Smart motorway strategies.
Actuate UK urges change of deadline to at least December 2022.
Study shows harmful impact of late payments on SME personnel.
Upcoming changes to the commercial supply and purchase of chemicals.
CLC introduces card for learners.
CIOB members recognised for public procurement.
Experts discuss the complex issues damaging the supply chain.
The co-founder of Get Kids into Survey discusses career paths for kids.
Report examines lack of detail in the Government's vision.
Our director Gregor Harvie hosts 4 webinars at the IHBC marketplace on Friday.
Look up construction terms on any website direct from your browser.
The revival of the public sphere in Toronto.
The story behind the copycat architecture craze.
Insight into construction materials supply and demand issues.