Reliability assessment of design rules for stainless steel structures

Abstract

This paper presents a re-evaluation of the current partial resistance factors recommended in EN 1993-1-4 for the design of stainless steel elements. Material data from key stainless steel producers were collected and carefully analysed, and representative values of the over-strength and the coefficient of variation (COV) of the material yield strength and ultimate tensile strength, necessary for performing reliability analysis, were established. The EN 1990 Annex D First Order Reliability Method (FORM) was applied to a substantial pool of experimental results. At the cross-section level, stub column and in-plane bending test results were used to assess the γM0 partial resistance factor. At the member level, flexural buckling and lateral-torsional buckling test results were used to evaluate the γM1 partial resistance factor. It is revealed that the current recommended partial resistance factors in EN 1993-1-4 (γM0 = γM1 = 1.1) cannot generally be reduced, and in some cases, modified design resistance equations are required, if the current safety factors are to be maintained.