How is a structure with cables designed ?

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Advance Design can perform the calculation of both linear and non-linear analyses, except for the structures containing cable elements, which can be calculated only by non-linear analysis.

In the following example, we consider a metallic sunblind that is supported by cable elements. The structure description is shown in the following figure (Figure 1).

Figure 1. Structure description and loading state

All elements are made of steel S235. For this model, the column cross-sections are HEB360 and their base can be considered fixed. The span length is 2.5 meters. Vertical bracings have SHS50x5H cross-sections and are defined as bar elements. Cross-sections of tie beam and cantilever beams are SHS150x10H.

As seen in Figure 1, there are no planar elements defined. We define only a windwall element, which will transmit forces to adjacent elements.

The entire system is subjected to a vertical planar load (Fz = -3kN), which includes the self-weight of the planar element, and two horizontal forces (Fx = 25kN) that are applied at the beam to column connection.

The cable elements are made of steel S235 and have a diameter of 2 cm.

After defining the load combinations (see Figure 2), we create a static non-linear analysis. To see how to create a static non-linear case and setup its parameters, consult the FAQ: How is a nonlinear analysis created?.

Figure 2. Load combinations

To obtain valid results, the large displacement option must be activated. This option is in the properties window of the static non - linear case.

Figure 3. Properties window of the static non - linear case

Note: The element mesh size has a great influence on the computed results. For this example we choose a mesh size of 0.5 meters.

The following pictures present the results for a static non-linear analysis (combination No. 101 was used to compute the results).

Figure 4. Displacements of the analyzed structure

Figure 5. Axial force in elements of the analyzed structure