| Title |
The Optimum Structural Planning and Design of Steel Roof Trusses Using the Multi-level Dynamic Programming Method |
| Keywords |
multi-level dynamic programming method ; plane truss ; automated optimum design ; objective function |
| Abstract |
Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only configuration(howe, warren and pratt types etc.) of single truss as the number of panel and truss height, but also the truss layout in consideration of a given design plane. In addition to them, the selection of cross-sectional shapes of structural members have a considerable influence on construction cost.
It is difficult and important for structural designer to find optimum solutions for not only the shape of single truss but also the layout of trusses(the number of trusses to be constructed) on the whole structure. The most existing studies being dealt with optimization problems for only single truss but not the whole trusses. On the design of steel roof truss structures composed of plane trusses and purlins, the truss layout optimization on the whole structure as well as a configuration of single truss must be considered. Moreover, it is difficult to solve nonlinear optimization problems with complex design space and several kinds of design variables as a practical optimization of a whole structures. Therefore, in this study, multi-level optimization method is applied for the solution of complex optimization problem.
The purpose of this study is to develope automated optimum design programming algorithm for steel roof truss structures considering truss shape and layout simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel roof truss structures.
In case of steel roof truss structures including purlins, even if member weights may be same, the construction cost could be different according to the kinds of member sectional shapes. So I expressed the objective function as the function regarding to construction cost of whole truss structures. |