What Is a Shell Roof?

The shell roof is a thin shell structure of a building. A shell is a curved member that mainly withstands forces in the midplane caused by various actions. The thin shell structure is a curved thin-walled structure. According to the form generated by the curved surface, it is divided into cylindrical shell, dome thin shell, hyperbolic flat shell and hyperbolic parabolic shell. The shell can make full use of the material strength, and at the same time can combine the two functions of load bearing and enclosure into one. In actual engineering, it is also possible to use the cutting and combination of space curved surfaces to form buildings with strange and novel shapes that can adapt to various planes, but it takes more labor and templates. The advantage of the shell top structure is that it can evenly distribute the pressure to all parts of the object, reducing the pressure. Many building roofs use the principle of the shell roof structure ^[1] .

A person holds an egg and squeezes it so hard that it cannot be crushed no matter how hard it is. The reason why a thin egg shell can withstand this great pressure is because it can

There are many types of shell top structures. There are four kinds of shell shells, dome shells, hyperbolic flat shells and saddle shells.

(1) The cylindrical shell is composed of a shell surface, a side beam and a diaphragm member. The single-curved thin shell has a simple shape and is easy to construct. It is the most commonly used thin shell form.

(2) The dome shell is composed of a shell surface and a support ring, which has good space work performance. A thin dome can cover a large space and can be used in large public buildings such as planetariums, exhibition halls, stadiums, Synagogue, etc.

(3) The hyperbolic flat shell is composed of a bidirectionally curved shell surface and four-sided transverse partition members. It has a reasonable force, a thin thickness, and can cover a large space. It is economical and suitable for various halls of industrial and civil buildings or workshop.

(4) A hyperbolic parabolic shell is composed of a shell surface and an edge member, and its appearance characteristics are like a set of parabola suspended over two arched parabola. It is shaped like a saddle, so it is also called a saddle shell. The curved surface in the upside-down direction is like a tensioned cable net, and the curved surface upwards is like an arch structure. Interaction between tension and compression improves the stability and rigidity of the shell, making the shell surface very thin. If a part is cut from a hyperbolic parabolic shell, twisted shells of various shapes can be made ^[2] .