Genetic Algorithm And Its Application On Optimum Design Of Quantity For Shear Walls In Frame-Shear Structures

Frame-shear wall structures are applied widely in high-rise buildings in our country for its good serviceability and well aseismatic capability. In this structure, the horizontal load is mainly supported by shear walls because of their large rigidity, and only about 20% of that is supported by frames, therefore, the rigidity of whole structure is mostly determined by that of shear walls. In structure design, the rigidity of shear walls should not only satisfy strength, but also have certain lateral rigidity to prevent excessive distortion. If the rigidity is too small, the structure may distorted excessively and can't meet with the require of normal application, if it is too large, the natural period of vibration will decrease and seismic action will increase accordingly, and it is also a waste of material.In our country, the design of high-rise buildings is generally too conservative, for example, in the high-rise apartments with frame-shear wall structure in Shen Zhen, its shear walls is too thick (can reach 500～600mm) and too much, the section of its column is too large, the maximum elastic displacement angle between floors calculated is very small. Its material is not sufficiently used, and the cost is highly increased. As the development of calculation theory and improvement of calculation tools, it is very necessary to find a way to optimize the quantity of shear walls.Recently, scholars home or abroad advance many methods of calculating the quantity of shear walls, but most are qualitative analysis. The models, established in quantitative analysis and ignoring the spatial interaction between shear walls and frames, are comparatively simple.Genetic algorithm is mostly focus on the optimizations of truss and frame structures, and we know a little about it in optimizing of quantity for shear walls in frame-shear structures. In this paper, the author calculates the optimum quantity of shear wall by adopting genetic algorithm. Adopting mode analysis method to calculate seismic action and breaking up the whole structure into bars with finite element method, the model established can deal with the spatial characteristics of the building and the shear deformation of shear walls. After that, the author carries out the second optimization on quantity of shear wall along the altitude, and makes the analysis results more close to the optimal one.The application of genetic algorithm on optimum design of quantity for shear walls in frame shearstructures is carried out in this paper, this method is a new tryThe application of genetic algorithm on optimum design of quantity for shear walls in frame shear structures in this paper is a new attempt in structure optimization, broadens its applying area, and has great developing potential in this area.Generally, to ascertain the rigidity of shear wall, a value is assumed primarily according to the experimental formula, then the value is adjusted again and again until it is ascertained ultimately. The optimum program in this paper can ascertain the optimal quantity of shear wall in frame shear structure easily and correctly, avoid repeated and fussy adjustment of structure rigidity, therefore greatly alleviate the working intension of structure designer.