Statistical analysis of the material, geometrical and imperfection characteristics of structural stainless steels and members

Abstract

Current structural codes for steel structures such as AISC 360-10, AS 4100 and Eurocode 3 are based on the traditional member-based two-step design approach. However, the most recent versions of these Standards already incorporate preliminary versions of direct or one-step system-based design alternatives, which represent a change in the paradigm of structural design. These new direct systembased methods are based on the design-by-analysis concept and allow evaluating the strength of structures directly from numerical simulations. Nevertheless, it is necessary to build a rigorous structural reliability framework to investigate acceptable target reliability indices for structural systems and to provide adequate system safety factors, since these codes do not provide safety factors or reliability requirements for structural systems for design-by-analysis approaches. While this framework has been developed based on advanced Finite Element analysis for hot-rolled and cold-formed carbon steel structures in recent years in the form of the Direct Design Method (DDM), the framework does not exist for stainless steel structures. This paper presents the first step towards developing a systembased reliability framework for stainless steel structures by statistically characterizing the main random parameters affecting the strength of stainless steel structures through a comprehensive database collected from the literature. Based on the collected data, appropriate probabilistic models are proposed for geometric properties, material properties, imperfections and residual stresses of different stainless steel alloys and cross-section or product types. While primarily aimed at providing statistical data for system-based reliability analyses, the data is equally applicable to member-based reliability analyses as described in existing codes.

System-based reliability analysis of stainless steel frames under gravity loads

“…The statistical characteristics of the random variables defining the cross-section geometry (H, B and t), member (e0) and local (γ 2 ) imperfections, and the amplification factor Y for residual stress distributions in stainless steel RHS specimens adopted in this study were extracted from [43], in which extensive databases on stainless steel structural members were collated and analysed, and suitable probabilistic models were proposed. Note that the residual stress pattern has been assumed to be deterministic in this study, but assigned a random magnitude by applying a random amplification factor Y to the stress distribution values defined in the model proposed in [37].…”

“…The statistical characterization of the material parameters defining the stress-strain behaviour of stainless steel alloys is summarized in Table 7, based on the results reported in [43]. Note that the overstrength ratios (mean-to-nominal ratios) for the enhanced yield stress f y,enh and ultimate tensile strength f u reported in Table 7 refer to the nominal values corresponding to the European structural and material standards [2,34,35], which implies that the equivalent overstrength ratios relative to the ASCE 8 [20] or AS/NZS 4673 [22] specifications would be higher owing to the lower nominal values codified in these standards (as per the values reported in Table 2 against those given in Table 3 and Table 4).…”

Validation of Stainless-Steel CHS Columns Finite Element Models

“…Values of the material parameters could also be obtained, based on the informative Annex C of the European standard EN 1993-1-4 [ 15 ], from the tables in AS/NZS 4673 [ 16 ] or SEI/ASCE-8 [ 17 ]. Recently, a statistical study of not only stainless-steel material parameter values, based on the results consolidated over the last decades, has been conducted by Arrayago et al [ 18 ].…”

Combined effects of elevated temperatures and high strain rates on compressive performance of S30408 austenitic stainless steel

“…In the last decades, 304 austenitic stainless steel (ASS) has been increasingly used in engineering structures [1][2][3][4][5][6]. It has several advantages compared to carbon steel, such as high corrosion resistance and durability, maintenance, improved fire and impact/blast resistance, etc.…”

“…Several design codes have been developed to regulate the use of the stainless steel in civil engineering, such as CECS 410:2015 [7] and EN 1993-1-4 [8]. Until now, the material and structural behaviours of 304 ASS subjected to the single static, dynamic, cyclic and fire conditions are relatively well understood [1][2][3][4][5][6][9][10][11][12][13][14][15][16][17][18][19][20]. In addition to the loading conditions mentioned above, the structures may suffer combined fire and impact/explosion action during the lifetime [21,22], such as 9.11 terrorist attack and Qingdao pipeline leak explosion.…”