Advanced Analysis and Design of Steel Frames

Guo-Qiang Li, Jin-Jun Li

Preference :

With advantages in high strength, good ductility and fast fabrication and erection, steel frames are widely used for industrial, commercial and residential buildings. Currently, the common procedures for the structural design of steel frames worldwide are: (1) to conduct linearly elastic structural analysis to determine the resultants of structural members under various actions; and (2) to check the resultants against the limit states of structural members specified in the codes, based on the reliability theory for the limit state of structural members. However, drawbacks of the current approach exist in the following two aspects.
Firstly, the normal elastic analysis of steel frames takes account of only typical flexural, shear and axial deformations of frame components, and cannot consider effects such as shear deformation of joint-panels, flexibility of beam-to-column connections, brace buckling and nonprismatic sections (tapered members). Also, material and geometric nonlinearities and imperfection (residual stress and initial geometric imperfection) cannot be involved in linearly elastic analysis. Secondly, the structural members of a frame is generally in an elasto-plastic state when they approach limit states, whereas the member resultants used in limit state check are taken from the linearly elastic analysis of the frame. The incompatibility of the member resultants obtained in structural analysis for limit state check and those in real limit state results in uncertain member reliability.
To overcome the drawback mentioned above, the concept of Advanced Design has been proposed.
Second-order inelastic analysis is used in Advanced Design of steel frames to determine the structural
ultimate capacities, which considers all the effects significant for structural nonlinear behavior and is termed as advanced analysis. A large amount of achievements have been made in the past two decades on advanced analysis of steel frames. However, in the view of structural design, the reliability evaluation of structural systems should be incorporated into advanced analysis to make the steel frames designed have certain system reliability. Such structural design with definite system reliability is termed as advanced design. Unfortunately, little progress was reported in this area. In this book, a concept of reliability-based advanced design is developed and proposed for steel frames.
The first author of this book began to study the theory of structural reliability design in 1982 when he was in Chongqing Institute of Architecture and Engineering for his Master degree and began to study the theory of advanced analysis for steel frames in 1985 when he was in Tongji University for his PhD degree. The main contents of this book are actually the summarization of our research achievements in structural reliability design and advanced analysis of steel frames for over 20 years, including the contribution from Ms. Yushu Liu and Ms. Xing Zhao, who are the former PhD students of the first author. Two parts are included in this book. Part One is advanced analysis for beam (prismatic beam, tapered beam and composite beam), column, joint-panel, connection, brace, and shear beam elements in steel frames, and methods for stability analysis, nonlinear analysis and seismic analysis of steel frames.
Part Two is reliability-based advanced design for steel portal frames and multi-storey frames.
We are grateful for the advice from Prof. Jihua Li and Prof. Zuyan Shen who supervised the first author’s Master and PhD degree study and guide him to an attractive field in structural engineering.