Y.J. Shi

Design of large-span portal frame system

Publisher Summary The chapter examines a warehouse project in Beijing and discusses the design principle of large-span portal frames with complex system. The main rigid frames of this structure consists of two steel large-span frames whose spans are both 36m, some of the frames even have 72m long span, and a part of the structure has a suspended mezzanine floor. The supporting truss is applied under the 72m span frame to ensure the deflections between the frames of different spans compatible. The integral action between the frames and the supporting truss to resist load is considered in the design. The span of the beams in mezzanine floor approximates 30m and the beam depth is limited strictly. In the design, some columns are applied between the beams of mezzanine floor and the roof rafter to form a space frame, and provide adequate loading capacity and stiffness. The project provides a helpful reference to the design of similar structures.

The wind-induced vibration comfort analysis of wuhan international securities mansion

Publisher Summary The chapter analyzes the stochastic wind-induced vibration response of the 281m tall Wuhan International Securities Mansion in Wuhan, China, under turbulent wind. The analysis is performed in the frequency domain by means of a stochastic vibration procedure, including in the general-use finite element software ANSYS. The wind-induced displacement, velocity, and acceleration responses under along and across turbulent wind are obtained in the chapter. The wind-induced vibration acceleration responses based on the stochastic vibration analysis, and the current load and structural code for the design of building structures in China are computed and compared in the chapter. The comfortable demand subjected to the stochastic wind-induced vibration is checked. The studies indicate that the across-wind response is larger than the along-wind one, and the design requirement of human comfort for the sightseeing hall of the building is not satisfied. These results provide important information for the wind-induced vibration analysis of super tall buildings.

Geometric non-linear analysis of flexible supporting system

Publisher Summary In recent years, a new type of glass curtain wall, which is supported by flexible system, has been widely used. The flexible supporting system is usually constructed with steel bars or cables. After having been prestressed, most of the structural members become tension member under working load so that smaller cross-section is enough to resist the loading. At the same time, the pretension can also significantly increase the structural stability and stiffness. Normally, large deformation and displacement occur in flexible supported system on duty. The geometric nonlinearity should be considered when analyzing the structural behavior. A finite element model is proposed in this chapter to simulate the large deformation and pretension. The element stiffness matrix for pretension member is derived and the fundamental equations under global coordinate system are established in the chapter. Based on the numerical model, some typical examples of flexible supporting system are given. The findings are useful for the reference of the designer in using the efficient and elegant structural form of this system. A nonlinear numerical method has been developed and the geometric nonlinear analysis in pretension and external load stages has been performed. The influence of various design parameters, which include pretension, the area of cable, and the Depth-to-Width of the system, is studied in the chapter.