Common Membrane Structure Shapes

There are many different types of membrane architecture. From the point of view of its basic structure, most of them are evolved from four basic shapes: saddle, umbrella, arch, and ridge.

1, the saddle

The saddle-shaped surface is composed of four non-coplanar corner points and the edge components connecting the corner points. It is a typical form of reciprocal surface. Among these four corner points, there are usually two diagonal points for the high point and two for the low point. The edge members of the saddle-shaped membrane structure can be concrete beams or space steel trusses to form the so-called rigid boundary. A flexible boundary can also be formed by applying a large pretension to a side cable. Because the flexible boundary can adapt to the deformation of the film surface and avoid the folding of the film surface in the process of installation and loading, it is more commonly used. The saddle-shaped membrane structure has a small applicable span and is generally used in membrane structure skits.

2, umbrella

Umbrella membrane structure is also one of the common tensioning membrane structures. The characteristic of this structure is that the peripheral position of the membrane unit is relatively low, and it is usually fixed on the rigid side beam or the flexible side cable. One or more high points are arranged in the middle of the membrane unit, which is usually supported by independent columns, flying columns, or hanging rings. The entire membrane is tapered. In order to avoid excessive stress in the membrane near the high point, when the membrane unit has a large span, a nodal cable can be set between the high point and the boundary support point, so as to change the force transfer path inside the structure and avoid stress concentration in the membrane. The umbrella surface can also be used inversely in engineering.

3. Arch support

The arch supports the membrane structure to provide the continuous support point for the membrane material, the structure plane is mostly round or approximately elliptic. When the span is large, the orthogonal cable network is usually arranged between the middle arch and the lower edge members. Arch - supported membrane structure is often used in enclosed buildings.

4. Ridge valley style

Ridge valley type membrane structure is arranged in the two high points between each other parallel notochord, in the two low points between the arrangement of the valley cable, high and low alternate, the curved surface is wavy; The film surface between the notochord and the cable forms a negative Gaussian curvature surface. When the span of the structure is large or the load is large, some transverse reinforcing cables can be arranged between the notochord and the cable. The structural plane of the ridge valley membrane structure is mostly rectangular.

Although the models of the four basic types of membrane construction are different, they all follow the same principle, that is, a series of high points and low points are formed in the membrane surface through rigid supporting members or connectors. This is the basic characteristic of the reciprocal surface, that is, the boundary of the reciprocal surface does not lie in the same plane. Having grasped this principle, we can select the appropriate membrane structure modeling form according to the form of supporting members (mast, arch, or hanging ring) and the supporting mode to the membrane (point support or line support) in the actual design.

Landscape Membrane Structure