Optimization of Rafter and Frame structures

Objective. Trusses and frames are widely used in the design and construction of buildings and structures, since they have high load-bearing capacity and rigidity. At the same time, they have a significant mass. In order to reduce the mass and cost of rafter and frame structures, this article develops optimal design and calculation schemes using steels of different strengths. Method. The study is based on the theory and methods of design optimization. By studying the features of the frame and truss operation, the most loaded elements of the structures are determined. In accordance with this, steels of different strengths are selected, which ensures a decrease in the mass of the structure and its cost. Comparing various design and calculation schemes, the optimal distribution of steels of different strengths along the span of the structures is proposed. Result. The developed design and calculation schemes make it possible to reduce the mass and cost of frames and trusses by optimally distributing steels of different grades. Conclusion. The proposed solutions can find application in the practice of designing and constructing metal structures. Structural schemes of trusses and frames have been developed, where steels of different strengths are used, which in terms of weight and cost compare favorably with corresponding structures made of steels of the same strength (one grade).