| บทคัดย่อ(English) |
The aim of this research is to establish the optimal solutions for linear and nonlinear planesteel trusses employing genetic algorithm. The design criteria utilized in this study arestresses, bucking and slenderness ratio. The standard codes used for structural design are theallowable strength design (AISC/ASD 2005) and the load and resistance factor design (AISC/LRFD2005). The fitness value utilized herein is the total volume of steel used for a plane truss.Therefore the objective function is to seek the minimum weight (volume) of the structure underthe constraint that meets the AISC standard. From the research, it may be summarized that the optimal solutions including nonlinear effectsare nominally different from those without considering the nonlinear behavior depending on thestructural shapes. The nonlinear effect is evidently noticed when the structures have highslenderness ratio. Conversely, for structures with small slenderness ratio, the behavior ofnonlinearity becomes insignificant.. From this study, the results obtained from the proposedmethod not only meet the AISC code requirements but also exhibit 2030% reduction in totalweight of structures comparing with that obtained from the virtual work method. |
