Selection of space frame structure (II)

 Factors affecting the selection of space frames mainly include space frame production, installation methods, steel indicators, span size, stiffness requirements, plane shape, support conditions, and so on.

space frame

5, the stiffness of the space frame is much better than the plane roof frame, but between the various kinds of space frame, whether it is the horizontal stiffness or vertical stiffness, the difference is not small. A diagonally placed quadrangular cone space frame, is geometrically variable in itself, in the addition of edge members or a strong ring beam to ensure its geometric invariance. Generally speaking, the number of nodes and the number of rods is larger network frame, such as triangular cone network frame, hexagonal cone network frame, three-way network frame, and positive release quadrangular cone network frame, its stiffness is larger, on the contrary, such as diagonal release quadrangular cone network frame, tessellated quadrangular cone network frame, pumping triangular cone Ⅰ, Ⅱ type network frame, cellular triangular cone network frame, its number of nodes and rods is smaller, it is also smaller stiffness.

6, the plane shape for the circular, hexagonal, and polygonal frame, from the plane layout and architectural design, it is more appropriate to use a three-way frame, hexagonal cone frame, triangular cone frame, evacuated triangular cone Ⅰ, Ⅱ type frame and honeycomb triangle cone frame. Especially when the plane shape is positive hexagonal, the space frame of these kinds of space frames is regular. Rod type is less, and construction is convenient; if other types of space frame, the border near the space frame is not regular, more chaotic, more types of rods, construction production is inconvenient.

7, multi-point support network frame, the choice of orthogonal orthogonal put class network frame is more appropriate. Because of the multi-point support, this orthogonal put type space frame force performance than the inclined put type space frame is reasonable, deflection is also small after the four-point support space frame calculations show that, in the case of the same conditions, two-way orthogonal space frame and two-way orthogonal diagonal put the space frame of the maximum internal force ratio of about 5/7, the deflection ratio of about 6/7, and the diagonal put the type of space frame in the free boundary but also set up the edge of the rod, increasing the number of rods and materials. The number of rods and material consumption are increased. It is also suitable to use an orthogonal orthogonal type of space frame for the space frame with an opening on one side of three sides of the support. Peripheral support and multi-point support combined with the space frame can be used orthogonal put class space frame, can also choose oblique put class space frame, but generally should not be used in three-way space frame and triangular cone, hexagonal cone composed of the space frame.

8, the span is not greater than 40m multi-story building floors and span is not greater than 60m roof, can be used to reinforce concrete plate instead of steel chord of the combination of space frame; a combination of space frame should be used to put the quadrangular cone combination of the space frame, put the pumping quadrangular cone combination of the space frame, the two-way orthogonal combination of the space frame, inclined to put the quadrangular cone combination of space frame and honeycomb-shaped triangular cone combination of the space frame.

In general, the space frame selection is a more complex problem, and must be based on the principle of practical and economic, multi-program comprehensive analysis and comparison to determiRegarding the above-mentioned factors affecting the selection, the most important consideration should be given to the construction of production and steel indicators of these two factors.