A simplified method for instability and second‐order load effects of framed structures: Story‐based approach

Abstract

Summary Several building codes such as ANSI/AISC 360‐16 and EC3 EN 1993‐1‐1 require the use of a proper design method to consider instability and second‐order load effect problems for individual system elements and the entire structural system. Various methods are available to assess stability. All of these methods should consider P‐Δ and P‐δ effects (second‐order effects). The following calculation procedures are presented in this study: (a) a simplified method is developed for P‐Δ and P‐δ analysis in regular frames under the effect of constant axial loads to obtain story drifts and end moments; (b) this method can be applied to an entire building or any individual story, that is, story‐based design is possible; and (c) column effective length factors are obtained for individual columns. In addition, design tables are presented.

Effects of beam axial deformations on storey-based critical gravity loads in tension-only semi-braced steel frames

“…In fact, the research on storey-based stability performed on semi-braced frames thus far [1,[4][5][6]11,[15][16] have assumed the presence of rigid diaphragms. Similarly, existing storey-based stability analysis methods for unbraced and braced frames [1,9,14,27,32] have also assumed the presence of rigid diaphragms. As such, the aforementioned methods may yield non-conservative results for the critical gravity loads of the frames.…”

“…The prevention of instability in the design of structural frames is of primary importance. The topic of storey-based stability in steel frames has been continually investigated over the last few decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

“…Other researchers [7][8][9][10] have since developed various similar methods for estimating the storey-based critical loads of storey frames. The effect of interactions between adjoining members across multiple storeys towards the computation of storey-based stability has also recently been investigated [11][12][13][14].…”

An Alternative Approach to Obtaining Stiffness and Mass Matrices for Three-Dimensional Bernoulli-Euler and Timoshenko Beam-Columns

“…Among the end moments, the one with a greater absolute value is denoted as M2. The integration constants C1, C2, C3, and C4 are determined from the boundary conditions, which are as follows [6]:…”

“…Researchers have explored various approaches for assessing structure's stability in the analysis and design of framed structures and have presented many books and articles on this topic. Favorable information for determining the second-order effects and analysis methods can be found from the following studies [3][4][5][6][7][8][9][10]: Computer-aided designs are using in the analysis of structural systems the well-known method of this topic is the finite element method (FEM). For frame-elements are developed special technics of FEM is called matrix methods.…”