In today’s article we are going to discuss dome structures. If you have ever walked around London and come across St Paul’s Cathedral or the Millennium dome, you were probably in awe of these magnificent structures. When were domes first constructed and why can span incredible distances?
Domes were first built around 100 A.D when Roman builders discovered they could rotate an arch 360 degrees to create a dome. The first domes were constructed with solid stone.
Since the Roman era, modern day engineers have studied and developed the construction of domes. Modern day domes are incredible structures.
Domes outperform all other shapes in structural strength. The reason for this is that they can evenly distributed stress along the entire structure. There are two types of stresses in a dome meridional and hoop, meridional stresses travel vertically through the dome and are compressive throughout, hoop stress run around the circumference and change from compressive in the top to tensile in the bottom of the structure.
Domes are the most efficient structure for large spans, with an average thickness to span ratio of 1/250 which means a dome can span over a football pitch with 45mm thickness and use 30 percent less surface area to enclose the same volume as a traditional building. These qualities are important when considering sustainability of structures.
An interesting fact about domes, the larger a dome the more efficient it becomes, as doubling the diameter encloses 8 times the volume.