For instance the use of pre-stressed material that furnishes better behavior in, for instance, damping processes is inappropriate for Cu-based alloys for their ability to stabilize the martensite with time and producing unexpected paths in the phase coexistence trajectories. In general, successful use of SMA requires a deep and clear knowledge of the effective conditions related to each application and, also, what are the required characteristics of SMA. The working time scale is completely different, eventually the use of damper is immediate after the initial installation and the number of oscillations to be damped is, also extremely higher. In the application to stayed cables in bridges the required behavior is substantially different. Usually, the dampers are situated inside the house and the amplitude of summer–winter wave temperature effects is smoothed. The summer-winter temperature effects also require analysis. requires that the damper can realize around 1000 cycles of work without relevant changes and, also, that in the time interval between installation and earthquake (one or more decades) not appears changes related to diffusion processes related to meta-stability of the phases modifying the expected behavior of the material. In fact, the earthquake (near one minute with frequencies close to 1 Hz) and the eventual replicas. In the earthquakes, the SMA requirements are associated to the relatively reduced number of oscillations. This paper is centered in the required SMA behavior for their application to earthquakes damping in steel structures as in family houses and, also, in damping of stayed cables in bridges. It is concluded that this method can serve as a useful tool in engineering design and optimization. The implemented method is tested on 10 members of 2D steel structure, 25 members of 3D steel structures and 72 members of 3D steel structure, where the results are compared with previous researches. The purpose of this paper is to discuss combining SAP2000 structure analysis program with genetic algorithm for optimizing steel truss structure.
'Home-written' structure analysis program can be designed to achieve this task, but it may suffer from serious drawbacks such as bugs, lack of user friendliness, lack of generality, and unproven reliability. However, commercially available finite element programs are not designed for optimization tools. The use of nonlinear finite element can assist greatly in achieving a safe design. Genetic algorithms (GA) have been shown to be effective optimization tools for practical optimization problems. An approach is presented for the optimization of steel truss by combining evolutionary algorithms and commercial structure analysis program.
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