1, Basic concepts
Optimization design of steel structure refers to the use of advanced computer-aided design tools, according to the engineering design objectives and design conditions, through the optimization of structural shape, cross-section size, material properties and other parameters, with the minimum material consumption, minimum engineering costs, maximum engineering benefits as the goal, to achieve the optimal design of the structure. The optimization design of steel structure can not be achieved without advanced computer technology and a large number of experiments and simulation studies, so it needs high-level technical personnel and good design methods.
2, Design principles
（1） Rationality and safety of the structure
In the optimization design of steel structure, it is necessary to consider the overall rationality and safety of the structure, follow the establishment of the stability, bearing capacity and reliability analysis model of the structure, and then carry out the optimization design of the structure. At the same time, it is necessary to ensure the safety of the structure and ensure that the structure will not produce plastic instability and general instability under the action of load.
（2）Reasonable selection of materials
In the optimization design of steel structure, it is necessary to consider the reasonable choice of materials. The selection of materials should take into account the implementation standards and design requirements of the structure, while taking into account the actual construction process and engineering costs. The optimized material should meet the requirements of structural strength, stiffness, durability and safety.
3, optimization methods
（1）Structure optimization
The optimization of the form of steel structure refers to the adjustment of the distribution arrangement of the structure by optimizing the encryption or shortening of the beams and columns, reducing or increasing the section of the beams and columns, etc., so that the structural form of the steel structure is more reasonable, the material consumption in the structure is reduced, and the cost of the structure is reduced under the premise of meeting the design requirements. In addition, through quality optimization, the overall weight of the structure can be reduced and the service life of the structure can be improved.
（2）Section optimization
In the design of steel structure, the selection of section is very important. In the optimization design of steel structure, the steel consumption can be reduced by optimizing parameters such as the shape, size and wall thickness of the section. On the basis of determining the appropriate section shape and size, combined with the optimization of wall thickness, the optimal utilization of materials and the minimization of costs can be achieved.
（3）Material optimization
Optimization of materials is an important means to realize optimal design of steel structures. In the optimization design of steel structure, the optimal utilization of materials can be achieved by selecting high-strength steel, reducing the actual use of materials, improving the strength of materials and other methods.
