Ships are subject to various external forces when sailing in the wind and waves. It is often not advisable to achieve good safety effect by simply increasing the thickness and size of ship steel plate, because it not only increases the dead weight of the ship and reduces the effective carrying capacity, but also increases the structural strength of the ship by simply increasing the thickness of components and ship steel plate It also has little effect.
In the actual ship, the ship steel plate is often processed into various shapes and made into various sections, which greatly increases the strength, rigidity and stability of the structure, and obtains larger structural strength with relatively small size, which not only effectively reduces the amount of steel, saves the construction cost, but also reduces the ship's dead weight and improves the cargo capacity.
In marine section steel, some section steel can be rolled directly by steel manufacturer, such as bulb flat steel, channel steel, round steel, etc., so as to improve the production efficiency of shipyard. Some steel sections are assembled and manufactured by shipyards according to their own needs, such as some composite sections with relatively complex shapes and special-shaped materials with unique sizes, such as T-shaped sections and folded plates.
