Residual stresses in cold-rolled stainless steel hollow sections

Abstract

a b s t r a c tStainless steel exhibits a pronounced response to cold-work and heat input. As a result, the behaviour of structural stainless steel sections, as influenced by strength, ductility and residual stress presence, is sensitive to the precise means by which the sections are produced. This paper explores the presence and influence of residual stresses in cold-rolled stainless steel box sections using experimental and numerical techniques. In previous studies, residual stress magnitudes have been inferred from surface strain measurements and an assumed through-thickness stress distribution. In the present study, throughthickness residual stresses in cold-rolled stainless steel box sections have been measured directly by means of X-ray diffraction and their effect on structural behaviour has been carefully assessed through detailed non-linear numerical modelling. Geometric imperfections, flat and corner material properties and the average compressive response of stainless steel box sections were also examined experimentally and the results have been fully reported. From the X-ray diffraction measurements, it was concluded that the influence of through-thickness (bending) residual stresses in cold-rolled stainless steel box sections could be effectively represented by a rectangular stress block distribution. The developed ABAQUS numerical models included features such as non-linear material stress-strain characteristics, initial geometric imperfections, residual stresses (membrane and bending) and enhanced strength corner properties. The residual stresses, together with the corresponding plastic strains, were included in the FE models by means of the SIGINI and HARDINI Fortran subroutines. Of the two residual stress components, the bending residual stresses were found to be larger in magnitude and of greater (often positive) influence on the structural behaviour of thin-walled cold-formed stainless steel sections.

Laser-welded stainless steel I-sections: Residual stress measurements and column buckling tests

“…While the patterns and magnitudes of residual stresses in structural carbon steel cross-sections have been studied extensively [12,13], those in stainless steel sections [5,14,15], particularly welded sections [16][17][18][19] have received less attention.…”

Behaviour of structural stainless steel cross-sections under combined loading – Part II: Numerical modelling and design approach

“…For cold-rolled and seam-welded stainless steel tubular sections, Young and Lui [40], Cruise and Gardner [41], Jandera et al [42] and Huang and Young [43] carried out careful residual stress measurements and concluded that the magnitude of the membrane residual stresses was small compared to that of the bending residual stresses. In addition, as highlighted in [40][41][42]44], the effect of the through-thickness bending residual stresses is inherently incorporated into the measured material properties, since the coupons straighten during tensile testing. Thus, explicit inclusion of residual stresses in the numerical models was deemed unnecessary.…”

Testing and numerical modelling of austenitic stainless steel CHS beam–columns

“…(6), for input into ABAQUS, where σ true is the true tress, pl ln  is the logarithmic plastic strain, and σ nom and ε nom are the engineering stress and strain, respectively. Residual stresses were not explicitly incorporated into the modelled sections, principally due to the negligible influence of membrane residual stresses on coldformed stainless steel tubular profiles and the inherent presence of the more dominant through-thickness residual stresses into the measured material properties [43][44][45]. With regards to end section boundary conditions, all degrees of freedom for the nodes of the loaded end were coupled to an eccentric reference point, which only allowed longitudinal translation and rotation about the axis of buckling, in order to simulate pin-ended boundary conditions.…”