When the ship is installed inside, the reason for the design of its portholes as round is not for aesthetic reasons, but for some scientific reasons. According to the principle of mechanics, a circle can withstand stresses such as compression and shear better than other shapes. (when the material is deformed, an equal but opposite reaction force will be generated inside to resist the external force. The scattered internal forces concentrated at one point are called stresses

If the porthole is rectangular or rhombic, the stress will be concentrated on the corner of the rectangle or diamond under the action of external pressure, shear force and other forces; when the stress is large to a certain extent, the porthole angle will often deform or break. This will greatly reduce the strength of the hull structure and affect the safe navigation of the ship. Round portholes are different. When a part of it is subjected to an external force, it will distribute the external force evenly to each part. In this way, the damage caused by excessive stress concentration can be avoided to a certain extent.

According to the mathematical principle, the area of a circle is larger than that of any other shape under the condition of a certain circumference; this means that the amount of light in the round porthole is roughly the same when the construction quantity, leakage amount and leakage amount are roughly the same. Big. In addition, the circle is very beautiful. Based on the above reasons, the designer chose the round shape as the ship's porthole shape.