scholarly journals A comparative analysis of resistance models for austenitic stainless steel girders subjected to concentrated loads

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Carlos Alberto Graciano-Gallego ◽  
Nelson Loaiza ◽  
Euro Casanova
Keyword(s):  
Stainless Steel ◽  
Comparative Analysis ◽  
Austenitic Stainless Steel ◽  
Element Model ◽  
Carbon Steels ◽  
Steel Beams ◽  
Concentrated Loads ◽  
Wide Range ◽  
Patch Loading ◽  
Nonlinear Finite Element Model

The increasing use of stainless steel in construction has led to the need of developing resistance models for structural elements made of this material. Unlike carbon steels, stainless steel alloys exhibit stress-strain curves with a pronounced strain hardening capacity and reasonable ductility that should be considered in the design. This difference in behavior makes the formulations used for carbon steel conservative when designing with stainless steel. Therefore, this paper presents a comparative analysis of resistance models for slender austenitic stainless-steel beams subject to concentrated loads. First, the failure mechanisms of stainless-steel beams are presented using a nonlinear finite element model. From this validated numerical model, a database obtained from a parametric analysis that covers a wide range of geometries is presented. Subsequently, this database is used to perform a comparison between various resistance models available in the literature. These models correspond to both international design codes and models obtained through machine learning. Finally, the numerical results show considerable improvement in the predicted ultimate resistances for slender stainless steel plate girders subjected to patch loading.

Development of New Design Fatigue Curves in Japan: Discussion of Best Fit Curves Based on Fatigue Test Data With Large Scale Piping

2018 ◽  
Author(s):  
Masaru Bodai ◽  
Yuichi Fukuta ◽  
Seiji Asada ◽  
Kentaro Hayashi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Large Scale ◽  
Fatigue Tests ◽  
Carbon Steels ◽  
Surface Finishing ◽  
Low Alloy Steels ◽  
Fatigue Data ◽  
Alloy Steels ◽  
Best Fit

In order to develop new design fatigue curves for austenitic carbon steels & low alloy steels and stainless steels and a new design fatigue evaluation method that are rational and have clear design basis, Design Fatigue Curve (DFC) Phase 1 subcommittee and Phase 2 subcommittee were established in the Atomic Energy Research Committee in the Japan Welding Engineering Society. The study on design fatigue curves was actively performed in the subcommittees. In the subcommittees, domestic and foreign fatigue data of small test specimens in air were collected and a comprehensive fatigue database was constructed. Using this fatigue database, the accurate best-fit curves of austenitic carbon steels & low alloy steels and stainless steels were developed by applying tensile strength to a parameter of the curve. Regarding design factors on design fatigue curves, data scatter, mean stress correction, surface finishing effect, size effect and variable loading effect were investigated and each design factor was decided to be individually considered on the design fatigue curves. A Japanese utility project performed large scale fatigue tests using austenitic stainless steel piping and carbon and low-alloy steel flat plates as well as fatigue tests using small specimens to obtain not only basic data but also fatigue data of mean stress effect and surface finishing effect. Those test results were provided to the subcommittee and utilized the above studies. In this paper, the large scale fatigue tests using austenitic stainless steel piping and the best-fit curve of austenitic stainless steel are discussed.

Fatigue Properties of Austenitic Stainless Steel with Circumferential Notch

2007 ◽  
Vol 353-358 ◽  
pp. 243-247
Author(s):  
Nobusuke Hattori ◽  
Shinichi Nishida ◽  
Y. Yano ◽  
J. Ding
Keyword(s):  
Stainless Steel ◽  
Stress Concentration ◽  
Austenitic Stainless Steel ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Fatigue Cracks ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Fatigue Properties ◽  
Micro Cracks

The effect of stress concentration factor on the fatigue properties of typical austenitic stainless steel SUS304 have been investigated using the circumferentially notched specimens. The notch of specimens has six kinds of radii, i.e. ρ = ∞ (i.e. plain specimen), 2.0, 1.0, 0.6, 0.3, and 0.1 mm with constant notch depth (t=0.2mm). Though the fatigue cracks in the specimens with a blunt notch initiate at one point, those in the specimens with a sharp notch initiate at several points. There exist the slip bands in the surface of the specimen under the stress amplitude of fatigue limit by 1×107 cycles, and do not exist the non-propagating micro-cracks in all kinds of the specimens. Furthermore, it has been found that notch sensitivity of austenitic stainless steels is higher than that of a typical plain carbon steels under the higher stress concentration factor region.

A numerical investigation of overstrength and ductility factors of moment resisting steel frames retrofitted with GFRP plates

2014 ◽  
Vol 41 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Mohammad Al Amin Siddique ◽  
Ashraf A. El Damatty ◽  
Ayman M. El Ansary
Keyword(s):  
Steel Frames ◽  
Local Buckling ◽  
Element Model ◽  
Steel Beams ◽  
Shell Elements ◽  
Glass Fiber Reinforced ◽  
Moment Resisting ◽  
Spring System ◽  
The Moment ◽  
Nonlinear Finite Element Model

This paper reports the results of an investigation conducted to assess the effectiveness of using glass fiber reinforced polymer (GFRP) plates to enhance the overstrength and ductility factors of moment resisting steel frames. The GFRP plates are bonded to the flanges of steel beams of the frame with an aim to enhance their local buckling capacities and consequently their ductility. The flexural behaviour of GFRP retrofitted beams is first determined using a nonlinear finite element model developed in-house. In this numerical model, consistent shell elements are used to simulate the flanges and web of the steel beam as well as the GFRP plate. The interface between the steel and the GFRP plate is simulated using a set of continuous linear spring system representing both the shear and peeling stiffness of the adhesive based on values obtained from a previous experimental study. The moment–rotation characteristics of the retrofitted beams are then implemented into the frame model to carry out nonlinear static (pushover) analyses. The seismic performance level of the retrofitted frames in terms of overstrength and ductility factors is then compared with that of the bare frame. The results show a significant enhancement in strength and ductility capacities of the retrofitted frames, especially when the beams of the frame are slender.

Residual Stresses in Austenitic Stainless Steel due to High Strain Rate

2011 ◽  
Vol 681 ◽  
pp. 278-283 ◽  
Author(s):  
Kenji Suzuki ◽  
Takahisa Shobu
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Strain Rate ◽  
Compressive Residual Stress ◽  
Tensile Deformation ◽  
X Rays ◽  
Lattice Plane ◽  
Wide Range ◽  
The Difference

Austenitic stainless steel (SUS316L) was used as specimen material, and the plate specimens were deformed plastically with a wide range of strain rates (6.67×10-5~ 6.70×102/s). The residual micro-stress for each lattice plane was measured with hard synchrotron X-rays. The residual macro-stress due to tensile deformation depended on strain rate. The residual micro-stresses varied from tension to compression, depending on the diffraction elastic constant. The soft lattice plane had tensile residual stress, and the hard lattice plane had compressive residual stress. The higher the strain rate, the smaller the difference in residual micro-stresses. The residual micro-stresses of the surfaces peened with the laser-peening or water-jet-peening were examined. Both surfaces had exhibited large compressive residual stress. The residual micro-stress on the peened surfaces showed a tendency opposite to residual micro-stress due to tensile deformation.

Hot Isostatic Pressing of Austenitic Stainless Steel Powders for Pressure Retaining Applications

2004 ◽  
Author(s):  
W. Barry Burdett ◽  
Paul Hurrell ◽  
Alan Gilleland
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Structural Integrity ◽  
Complex Geometry ◽  
Hot Isostatic Pressing ◽  
Cost Savings ◽  
Nuclear Industry ◽  
Metal Powders ◽  
Isostatic Pressing ◽  
Wide Range

Hot Isostatic Pressing (HIP) has been used for many years to consolidate porosity in cast metal shapes to improve mechanical properties. When the technique is applied to fine metal powders, it becomes possible to produce Near Net Shape (NNS) items and more complex geometry components that are fully dense and offer an attractive set of properties and reduced cost. Manufacture of NNS items from powder delivers cost savings by reducing initial material usage and subsequent machining costs. Powder production and HIP processing are automated methods, which also provide protection against forging route obsolescence. Setup costs are lower and smaller batch sizes possible. HIPped powder microstructures are isotropic and equi-axed, with uniformly fine grain sizes not normally achieved in heavy section components. In austenitic stainless steel materials, this provides significant improvements in ultrasonic NDE (Non-Destructive Examination) in thick sections. Use of the technology has grown, particularly in the off-shore oil industry where it is already established in high integrity applications, but take-up in the more conservative nuclear industry has been slow. In a broad programme of testing, Rolls-Royce has established that HIPped powder 316L components, in items up to several tons in weight, have equivalent or slightly better strength, toughness and corrosion properties across a wide range of test environments. A methodology for developing robust safety justifications for use has been developed. Manufacture of pressure seal components is now in progress and the economics of other applications such as pump bowls are being considered. The quality of HIPped powder items can provide through life cost savings since there is greater assurance of structural integrity compared to welded or wrought components.

scholarly journals Microstructure Evolution During Hot Deformation of REX734 Austenitic Stainless Steel

2019 ◽  
Vol 51 (2) ◽  
pp. 845-854 ◽  
Author(s):  
Mykola Kulakov ◽  
Jianglin Huang ◽  
Michail Ntovas ◽  
Shanmukha Moturu
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Compression Testing ◽  
Recrystallization Process ◽  
Twin Boundaries ◽  
Wide Range ◽  
Evolution Of Microstructure ◽  
Backscatter Diffraction

AbstractMechanical properties of a REX734 austenitic stainless steel were examined through compression testing over a wide range of temperatures (1173 K to 1373 K (900 °C to 1100 °C)) and strain rates (0.1 to 40 s−1) that cover deformation conditions encountered in different metalworking processes. The evolution of microstructure was studied using electron microscopy combined with electron backscatter diffraction and energy-dispersive spectroscopy. Partially recrystallized microstructures were obtained after compression testing at 1173 K (900 °C), while after deformation at 1273 K and 1373 K (1000 °C and 1100 °C), the material was fully recrystallized almost in all examined cases. The role of dynamic and metadynamic restoration processes in the formation of final microstructure was investigated. Σ3 twin boundaries lost their twin character and transformed into general high-angle grain boundaries as a result of deformation, while during recrystallization new Σ3 twin boundaries formed. The evolution of precipitates during compression testing and their role in the recrystallization process was also discussed.

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