The basis for load and resistance factor design criteria of steel building structures

Abstract

This paper will detail the assumptions, the first-order probabilistic basis, the calibration, and the proposed format of load and resistance factor design (LFRD) criteria for steel building structures. Specifically, the paper will concern itself with the background and the choice of the particular first-order model, with the data bases used in evaluating the loading and the resistance functions, with the calibration procedures, and with the final selection of the load and resistance factors. The method will be illustrated by the examples of beams and columns under dead and live loading. The paper will conclude with a brief review of the research work done in connection with the development of LRFD criteria for steel building structures.

Lateral–torsional buckling assessment of steel beams through a stiffness reduction method

“…In practical design, this may be accounted for by two alternative approaches: (i) use of semi-empirical design equations reducing the ultimate cross-section bending resistance through buckling reduction factors [1][2][3][4][5] (ii) reduction of stiffness [6][7][8][9]. Though the latter may be seen to represent the actual physical response more realistically, the former has traditionally been adopted in steel design specifications [10][11][12] as its applicability is well suited to hand calculations.…”

Reliability assessment of composite beams

“…Consistent with previous work of Galambos and Ravindra [12], values of α = 0.55 and β = 3.0 are used in this study. The former was found to be the proper separation coefficient between load and resistance effects, while the latter was derived based on calibration with simple compact beams to achieve a similar level of safety [7].…”

“…This simplified method uses two statistical pieces of information, means and coefficients of variation (C.O.V.). Reliability (β) is the relationship between these two measures [12]. This method was first developed by Cornell and Ravindra et al [13,14] and its concepts used in this study are outlined below.…”

On the Seismic Design of Structures with Tilting Located within a Seismic Region

“…There are several methods in the literature to estimate the reliability of structures. For example: (a) the semi-probabilistic [24], (b) first order and second moments (FOSM) [25][26][27], (c) load and resistance factors design (LRFD) format [28,29], (d) those based on seismic hazard or risk analysis [30][31][32][33][34], and (e) those based on optimization [35][36][37][38]. In the present study, the structural reliability is evaluated by means of seismic hazard analysis.…”