Arch-shaped Beams: Understanding Load Carrying Capability

[Toby_Obie]

If a beam is arched, how does this affect its load carrying capability ?

Considering the same beam bent into two different formations (below) - which would be stronger ? (if any difference)

1. A long arch (horizontal distance between two ends) of low height (max vertical height of arch)

2. A short arch of high height

Thanks

 

[Lok]

The second one if I understood the english :P.

The gothic arches which were pointed, so not true arches, were the reason reneissance buildings got so tall. The load on a round arch is strong in it's highest point (no way to say it different) as the load travels downward on structure near horizontaly angled. The gothic arch or the small high (you named it) one will distribute the load on vertical structures, where materials have a better load resistance. Hope I am understandable.

http://www.sirgeorgetrevelyan.org.uk/books/images/bk-arch-fig06c.gif

 

[pongo38]

There is a significant difference between an arch-shaped beam which is simply supported, and the same shape beam with rigid abutments or a tie between the supports. Only the rigid-abutment one is a true arch. Nevertheless all beams including ones that don't look like arches can exhibit internal tied-arch behaviour. To understand this more fully you need to be conversant with bending moment diagrams and lines of thrust.