Standard methods are used to determine cross sections for compressed, tensile and zero steel bars with flexibility limits (compressed bars = 120, tensile bars = 200 and zero bars = 150).

 In all cases weight of the best truss is compared to the weight of base steel standard model.

 This solution is rather general - hinges are scattered at random with 2 bars each to make structure geometrically stable. Mutations are also applied to the position of hinges.

 Loads are shown on the trusses and there may be any number of load combinations - like it's in real construction design.

Two examples (Figure 1 and Figure 2) are shown for a single load - a force is applied to one hinge.

Another example (Figure 3) is shown for a single load - forces are applied to every hinge of lower chord.

On Figure 4 example is shown for a combination of 8 loads: a force is applied in succession to every hinge of lower chord - moving load.

Figure 5 shows an example to get more optimal truss for chosen shape with fixed number of hinges.

Figures 6,7 show shape dependence upon load value. Different shapes of trusses for different values of force are due to influence of compressed bars flexibility and flexibility limits for all bars.

Figure 7,8 shows possibility of implantation of one and two forbidden areas for bars and hinges by modifying fitness function to get necessary restrictions on shapes. It's important to point out - not by changing algorithm - but by changing environment. It's like in living world - changing environment - changing biological species (giraffe, whale, etc.).

Figure 9 shows plane structures upon different load values also with implantation of forbidden area.

Figure 10 shows weight of steel plane structures for different values of flexibility limits for bars. Normal flexibility limits are taken as follows:
       compressed bars = 120, tensile bars = 200 and zero bars = 150.