Full slenderness range DSM approach for stainless steel hollow cross-section columns and beam-columns

Abstract

The behaviour of austenitic, ferritic and duplex stainless steel Rectangular and Square Hollow Section members subjected to compression and combined loading is investigated in this paper. A full slenderness range Direct Strength Method (DSM) approach is proposed based on experimental results and numerical strengths obtained from FE parametric studies. The method accounts for local buckling effects and enhanced material properties are also incorporated for those members stable enough to allow partial yielding of the cross-sections. The proposed method is based on strength curves previously provided for cross-sections although additional limitations have been adopted. The DSM approach for columns is based on existing buckling curves and provides accurate resistance predictions for slender and stocky cross-sections. The proposed DSM approach for beam-columns also improves capacity predictions for stocky and slender cross-sections obtained from the traditional methods for different bending moment distributions. This is attributed to the fact that the beam-column behaviour is directly calculated with a unique strength curve, considering the member and section slendernesses based on the elastic instabilities of the section subjected to the actual stress distribution instead of calculating the compressive and flexural strengths independently and combining these through an interaction equation, as is the traditional uncoupled approach. Finally, a reliability study of the full slenderness range DSM approach is presented to determine resistance factors for the different stainless steel grades columns and beam-columnsPostprint (author's final draft

Design of austenitic and duplex stainless steel SHS and RHS beam-columns

“…The direct strength equations for the normalized design strength for beam-column member of carbon steel ( * ) and stainless steel ( * ) are shown in Eq. 11 [27], and thus it complements Arrayago et al [27] in assessing suitability of design rules for stainless steel beam-columns.…”

“…Arrayago et al [27] proposed two direct strength equations of beam-column members for carbon steel and stainless steel materials, in which local buckling and enhanced material strength are considered. Therefore, calculation of effective area is not required, as the local buckling effect is considered through direct strength curve.…”

“…Huang and Young [23,24] and Zhao et al [25,26] investigated the beam-column behaviour of lean duplex stainless steel SHS and RHS. Arrayago et al [27,28] conducted experimental study on ferritic stainless steel beam-columns, in order to assess current design rules for stainless steel beam-column members. The test results of ferritic stainless steel beams [29], stub columns [30] were also used in comparing with design specifications.…”

“…Several design recommendations were proposed for stainless steel beam-column tubular members. Arrayago et al [27] examined various design proposals based on direct-strength method (DSM) for stainless steel hollow cross-section beamcolumn members, and proposed a full slenderness range DSM approach based on experimental and numerical results. The proposed DSM is capable of incorporating strain hardening for stainless steel materials and the actual stress distribution of the cross-section when determining the elastic buckling stress.…”

“…A finite element model is developed and validated with the beam-column tests conducted by Lui et al [22] and beam tests conducted by Zhou and Young [12]. The beam-column strengths obtained from the finite element analysis are compared with design strengths predicted by linear load-moment interaction curves and direct strength method for beam-column that described in Arrayago et al [27], with the compressive strength and flexural strength calculated by different design approaches.…”