When it comes to performing a big number, you have to Amount of rolled steel in kilograms will occupy an industrial unit, There is a pseudo-lower limit that seems very difficult to surpass.
When designing a hangar or industrial building, there's a curious magic number, common to all of them, which defines the amount of steel to be used in its construction.
A ship is a structure generally made of metal or a mix of materials (steel for the deck and concrete for the pillars) that usually covers large spans without intermediate pillars for its construction. Its character can be temporary or permanent, and the covering can be either canvas or sandwich panels. In the airport environment, its use is almost always for hangars, so the use of canvas is disregarded, as it could fall onto aviation equipment (planes, helicopters, etc.) due to the weight of snow or blow away in the wind. In any case, the purpose for which the structure was conceived must never be lost, meaning it should be Stable, resistant and with limited deformation, necessary for maintenance, repair, or storage.
There is a high degree of variables that will ultimately define the rolled steel sections necessary for a definitive structure, such as the span between main columns, spacing between frames, roof shape, height, presence or absence of overhead cranes, as well as the different load hypotheses involved, such as self-weight, wind, seismic activity, snow, etc.
Obviously, there are some variables that are much more defining than others in the final calculation, but The magic number that they all reach is 45 kg/m². What does this number mean? Basically, from the area we need to cover and multiplying by it, we will get the total number of kilos to be used on the ship. Once this value is obtained, we only need to multiply it by the price per kilo of steel to get, with a very high approximation, the price of the structure.
But not everything is that easy, as there are some buts or drawbacks to the previous approximation, such as:
- Using a type of steel with a lower yield strength (235 N/mm2) compared to one with a higher yield strength (355 N/mm2) leads to distortions in the previously calculated value.
- Having spans over 40-50 metres. As soon as we exceed this distance, the kg/m² of the structure begin to rise, because to maintain the imposed deformations, these increase with a fourth power exponent due to the span (L^4).
- To have overhead cranes suspended from the main roof structure, rather than supported by the pillars.
It can be concluded, and almost stated, that “any” vessel (maximum beam of 50 metres, S275 steel and possible overhead cranes supported on pillars) will be a "minimum flyweight", by analogy with boxing weights. Your weight will be 45 Kg/m². From here on, no régime will have any effect on our ship.
