求一篇关于钢结构的英语文献

In the past decade, the concept of a second-order or an advanced analysis has been described in various national design codes of practice such as the Load and Resistance Factor Design Specifi- cation for Structural Steel Buildings ( 1986 ) and the Australia standards ( AS4100 1990 ) . Unlike the 1inear analysis where checking of member strength against instability and second-order effect is carried out by the element design formulas in the codes, the second-order analysis automatically includes the effects of these nonlinear terms. As a result of this, stress, allowing for the second- order P-δand P-△ effects, can be automatically computed and compared with the factored yield stress, or the design strength, in the analysis so that the empirical approach to amplify the moment due to a large change of geometry becomes unnecessary, resulting in much convenience and accuracy. In addition, the second-order and advanced analysis--including various linear and nonlinear terms for a more acc