【正文】 外文翻譯 An Innovative Design for Steel Frame Using Advanced Analysis Introduction The steel design methods used in the . are allowable stress design (ASD), plastic design (PD), and load and resistance factor design (LRFD). In ASD, the stress putation is based on a firstorder elastic analysis, and the geometric nonlinear effects are implicitly accounted for in the member design equations. In PD, a firstorder plastichinge analysis is used in the structural analysis. PD allows inelastic force redistribution throughout the structural system. Since geometric nonlinearity and gradual yielding effects are not accounted for in the analysis of plastic design, they are approximated in member design equations. In LRFD, a firstorder elastic analysis with amplification factors or a direct secondorder elastic analysis is used to account for geometric nonlinearity, and the ultimate strength of beamcolumn members is implicitly reflected in the design interaction equations. All three design methods require separate member capacity checks including the calculation of the K factor. In the following, the characteristics of the LRFD method are briefly described. The strength and stability of a structural system and its members are related, but the interaction is treated separately in the current American Institute of Steel Construction (AISC)LRFD specification [2]. In current practice, the interaction between the structural system and its members is represented by the effective length factor. This aspect is described in the following excerpt from SSRC Technical Memorandum No. 5 [28]: Although the maximum strength of frames and the maximum strength of ponent members are interdependent (but not necessarily coexistent), it 浙江大學城市學院畢業(yè)設(shè)計 外文翻譯 is recognized that in many structures it is not practical to take this interdependence into account rigorously. At the same time, it is known that difficulties are encountered in plex frameworks when attempting to pensate automatically in column design for the instability of the entire frame (for example, by adjustment of column effective length). Therefore, SSRC remends that, in design practice, the two aspects, stability of separate members and elements of the structure and stability of the structure as a whole, be considered separately. This design approach is marked in Figure as the indirect analysis and design method. In the current AISCLRFD specification [2], firstorder elastic analysis or secondorder elastic analysis is used to analyze a structural system. In using firstorder elastic analysis, the firstorder moment is amplified by B1 and B2 factors to account for secondorder effects. In the specification, the members are isolated from a structural system, and they are then designed by the member strength curves and interaction equations as given by the specifications, which implicitly account for secondorder effects, inelasticity, residual stresses, and geometric imperfections [8]. The column curve and beam curve were developed by a curvefit to both 浙江大學城市學院畢業(yè)設(shè)計 外文翻譯 theoretical solutions and experimental data, while the beamcolumn interaction equations were determined by a curvefit to the socalled “exact” plastic zone solutions generated by Kanc