Steel structure engineering design methods and matters needing attention

Steel structure engineering design methods and matters needing attention

1. Steel structure engineering design method

1.1 Plastic design method

When the plastic property and strength of the structural members of the steel structure engineering are higher than that of the standard load members multiplied by the safety factor, the plastic design method is usually used in the internal force structural analysis of the members. This method has certain advantages, mainly in its structure into the plastic can allow the redistribution of internal forces, but it should be noted that the structure and components need to have enough ductility, and in the design process according to the actual needs, strictly limit the proportion of flange and cross-section web size.

1.2 Allowable stress method

The allowable stress method of steel structure engineering also needs to adhere to certain principles in the process of design and application, specifically, it requires that the calculated stress of its structure needs to be smaller than the allowable stress specified in the design of structural members. When calculating the stress of the structural member, it must be designed in accordance with the specified standard load, and the calculation is obtained by the first-order elastic theory, which is determined by the ultimate stress or yield stress that removes the material and is greater than the safety factor of 1. This design method has some defects, and it needs to be selected scientifically according to the actual situation in the application process.

1.3 Limit state method

The emergence of limit state method can effectively solve the defects in the above two methods and improve the design quality better. The limit state method uses load component factor and resistance to replace single safety factor. Under the action of load, the structure can reach two limiting states within a certain period, that is, the limit state under normal use and the limit state of bearing capacity. The latter corresponds to the safety of the structure, which mainly refers to the structural damage caused by structural fracture and plastic deformation. Limit state is a widely used design method in steel structure engineering design, which can effectively improve the design quality and ensure the stability of building steel structure.

2. Precautions for steel structure engineering design

2.1 Reasonable selection of steel

In the process of steel structure engineering design, the selection of reasonable steel plays a very important role. It can be said that the task of steel selection is both important and difficult. There are many kinds of steel in China, and it is difficult to choose the steel suitable for the construction and construction of steel structure engineering from many steels, and the current construction design of steel structure engineering has higher requirements for steel, and different steel structure projects have different requirements for steel structure strength, deformation and fatigue stress, so there are certain difficulties in the selection. Therefore, in the design, in order to be able to better play the role of steel structure, we must proceed from the actual, combined with the specific construction requirements of scientific selection of steel. In the selection of steel, it is also necessary to scientifically determine its applicability. At present, the span and load of building steel structures are relatively large, mainly used in high-rise steel structure projects with more complex types or large-scale steel structure projects. Therefore, steel must meet the construction needs of steel structure engineering, can withstand high temperature and vibration, and is easy to disassemble. This requires the designer to investigate and study before the design, and analyze all aspects, and fully consider the applicability of the steel structure, in order to carry out the design work.

2.2 Design the details of the steel structure

The design of the details of the building steel structure often has an important impact on the stability of the entire structure. Therefore, it is necessary to pay attention to the design of this aspect. This requires the designer to determine the steel structure after the scheme, it is necessary to carry out specific calculations of the steel structure's stress system and detailed nodes, and to scientifically improve according to the actual situation. For the design of the steel structure stress system, most of the current steel structure projects use rod structure, which requires steel to have a larger strength level, and the size of the section to meet the construction requirements, can be assembled on site during production, and the binding force between components is small. This requires designers in the design process must grasp the design of the key points to ensure the stability of the connection between component nodes. In the design of the detailed node, we must be careful, because the design content of the detailed node is more complex, it must be strictly designed, and it must meet the actual construction needs.

2.3 Improve the stability of steel structure design

Steel structure designers first need to analyze its stability from the integrity of the structure, and fully consider the overall stiffness of the steel structure and the degree of instability. At present, the stability of steel structure is calculated by the reduced coefficient method and the critical pressure solving method, which are also used to calculate the stability of the axial compression bar in general. Because the internal force of the building steel structure will be affected by the large deformation of the flexible structure, when calculating the elastic stability, it is not only necessary to consider the integrity of the structure, but also to fully consider the second-order analysis, which can not be ignored by the designer.

In the construction of steel structure engineering, the use of steel structure engineering design, not only can make the steel structure engineering has a larger span space, but also has the advantages of convenient installation and low cost, so it is more and more widely used in steel structure engineering. With the prosperity and development of China's industrial market, the number of steel structure projects will increase sharply, which puts forward higher requirements for the design of steel structure projects. As a relevant designer, it is necessary to master the key points in the steel structure engineering design work, so as to ensure that China's steel structure engineering design work can do better and promote the better development of China's steel structure engineering industry.