Finite element analysis of ribbed members Previous Next Filter Disc,Filter Disc Mesh,Stainless Steel Filter Disc Galvanized Steel Wire Co., Ltd. , http://www.nswiremesh.com
In the fixed roof of the "Bird's Nest" structure, the main structure, the sub-structure and the composite column are all welded box-shaped sections, and the joints are welded. In order to meet the architectural modeling requirements, the external dimensions of the components are greatly limited. The width of the main truss chord is 1200mm, the height is 800mm~1200mm, the width of the secondary structural members is 1200mm, the height at the roof is 800~1000mm, and the height at the façade is 1200mm.
The National Stadium "Bird's Nest" has a special structure and a large span of roof structure. The weight of the steel structure accounts for a large proportion of the internal forces of the members. Since the steel structure is directly exposed to the outside, temperature changes will cause large internal forces and deformations in the structure. For this particular structural system, it is important to ensure the safety of the structure in the event of a rare earthquake. Therefore, reducing steel consumption not only has direct benefits for saving investment and controlling cost, but also has great significance for reducing earthquake and temperature and enhancing structural safety.
In the design process of the National Stadium, in order to reduce the self-weight of the structure, there are two design schemes for the sub-structural members with less stress. One is to adopt the lattice-type members and the outer cover of the decorative thin steel plate. The other is to consider the use of lateral and longitudinal stiffeners inside the box section members. Therefore, the designer specifically studied the bearing capacity of the ribbed members and the non-ribbed members. Taking the welded box-shaped member of Q345 steel □1000×1200×8×8 as an example, the calculated length of the component is L=20.0m. The bearing capacity of the member without ribs, one longitudinal rib and two longitudinal ribs is studied. Figure 3 shows. The research results show that the stiffeners have a great effect on delaying the local buckling of thin-walled box members, increasing the bearing capacity of the members and reducing the amount of steel used. After the stiffener is set, the actual axial compression ratio of the thin-walled box-shaped member is improved, although a certain bearing capacity can be maintained after the ultimate bearing capacity is reached, but the ductility is weakened. Figure 4 shows the development of the plastic zone during the buckling of the box-shaped thin-walled member. 
Fig. 3 Axial force-axial deformation curve of ribbed thin-walled box-shaped members 
Figure 4 Plastic zone of box-shaped thin-walled members