Space frames

1. GENERAL

NILKA system Space frames are 3-D bearing structures with many advantages

Space frame, from a geometrical viewpoint, consists of two plane grids, parallel to each other, which form the upper and lower layers of the space frame. These two plane frames (grids) are connected to each other with the use of diagonal bars.

The external loads are distributed amongst the two parallel layers and the diagonal bars which connect them.

The axial distance between the upper and lower parallel layers is the space frame's structural height and it is equal to 0.707*a or 0.50*a , where "a" is the space frame's module.

2. SPACE FRAMES' COMPONENTS

The basic components of the space frames NILKA system are the sphere (node), the bars, the bolts and the sleeves

2.1 Nodes (spheres)

The nodes (spheres) of the space frame NILKA system undertake the external loads.

The forces acting radically on the spheres having different magnitudes and sometimes opposite directions, these forces are distributed through the bars which are attached to the nodes (spheres).

2.2 Bars

The bars of NILKA system space frame have a hollow circular section (CHS), their diameter and thickness depending on the maximum developed force.

The bars are made of seamed circular hollow sections in accordance with DIN 2458 or without seam in accordance with DIN 2448, of steel quality St 37-2 in accordance with DIN 17100.

2.3 Bolts

The bolts connect the bars with the nodes and also transmit tensions forces from the bars to the spheres.
They are made of high strength steel, in accordance with DIN 267, quality 8,8 and 10.9 with metric threading.

2.4 Sleeves

The sleeve is the component, which transmits the compression forces between bars and spheres.

The sleeve is made from hexagonal steel cross sections, in accordance with DIN 17100, St37-2.

3. ASSEMBLY-ERECTION OF SPACE FRAMES NILKA system

There are four basic methods for the installation of a space frame. These methods are described below. The proper method depends on the area's condition and the requirements of design.

3.1 Assembly - erection method

The area of the structure is covered by scaffolding and the assembly and installation of the space frame is done concurrently.

3.2 Lift-up method

The space frame is assembled on the ground near the final site and is then erected to the final positions with the use of cranes.

3.3 Block method

A section of the space frame is assembled on the ground, which afterwards is lifted up by crane and installed in position. Then another section is assembled on the ground, lifted up near the first one and the two sections are attached by construction workers working on suitable scaffoldings.

The process is carried on this way until the entire space frame is assembled and in position

3.4 Assebly - sliding method

Scaffolding is installed with the aid of which a part of the space frame is assembled, and then this part of the space frame is pushed on rails to its final position. Afterwards, a second part is assembled and is slid on rails to the final position in the same way. The two parts are joined together.

The process is repeated until the space frame is completely assembled and in position.