Design Guidelines for Architectural Uses of Stainless Steel

2009 ◽  
pp. 36-36-20
Author(s):  
W. F. Koppes
1982 ◽  
Vol 104 (2) ◽  
pp. 137-144 ◽  
Author(s):  
C. E. Jaske ◽  
N. D. Frey

Some energy-system structural components may be subjected to 107 or more cycles of small-amplitude, strain-controlled vibrations. In such cases, information on the elevated-temperature, long-life (>106 cycles to failure) fatigue resistance of the austenitic steels often used in these components is needed. Present design guidelines provide fatigue curves for these steels only up to 106 cycles to failure. The objective of the present study was to evaluate the long-life fatigue resistance of one such steel, namely Type 316 stainless steel. Strain-controlled long-life (> 106 cycles to failure) fatigue experiments were conducted on solution-annealed Type 316 stainless steel in air at temperatures from 21 to 593° C. These were all for continuous cycling of smooth specimens under fully reversed straining (no mean stress). Results of this work provided a major advance in understanding the fatigue behavior of this steel. Tentative best-fit fatigue curves have been developed, but more data are needed to establish needed statistical confidence in them. At 21°C, strain and load-controlled experiments gave similar fatigue-resistance values at 108 cycles when inelastic straining was taken into account. However, at 427°C and above, strain-controlled cycling yielded fatigue-resistance levels at 108 cycles about 15 to 25 percent above those for load-controlled cycling. This difference is related to the continually increasing stress levels observed under strain cycling at the higher temperatures. That is, cyclic hardening continues to occur for 105 or more cycles of straining with accompanying two- to threefold increases in strength. This increased strength gives the increased fatigue resistance at long lives. Under load-controlled conditions, such cyclic hardening cannot occur, and the fatigue resistance is lower. Results of this work emphasize the need for considering the intended service conditions in carrying out laboratory experiments. The impact of these results on recommended experimental procedures for long-life fatigue testing of such alloys is discussed. Finally, considerations for application of these data in fatigue design are addressed.


Author(s):  
Jiening Liu ◽  
Benjamin Hall ◽  
Mary Frecker ◽  
Edward W. Reutzel

A device that can provide articulation to surgical tool tips is needed in natural orifice transluminal endoscopy surgery (NOTES). In this paper, we propose a compliant articulation structure that uses superelastic NiTiNOL to achieve a large deflection angle and force in a compact size. Six geometric parameters are used to define this structure, and constraints based on the fabrication process are imposed. Using finite element analysis, a family of designs is evaluated in terms of the free deflection angle and blocked force. The same family of designs is evaluated for both NiTiNOL and stainless steel. It can be seen that significant benefits are observed when using NiTiNOL compared to 316 stainless steel; a maximum free deflection angle of 64.8° and maximum blocked force of 24.7 N are predicted. The designs are refined to avoid stress concentrations, and design guidelines are recommended. The meso-scale articulation structure is fabricated using both a Coherent Avia Q-switched, 355 nm laser and a Myachi Unitek 200 W single mode pulsed fiber laser with active water cooling. Select fabricated structures are then tested to validate the finite element models.


2016 ◽  
Vol 853 ◽  
pp. 301-305
Author(s):  
Shameem Ahmed ◽  
Mahmud Ashraf ◽  
Mohammad Anwar-Us-Saadat

Structural stainless steel design guidelines should appropriately recognise its characteristic beneficial properties such as material nonlinearity and significant strain hardening. The Continuous Strength Method (CSM) exploits those through a strain based approach for both stocky and slender cross-sections. In this paper, a new design method is proposed that combines the CSM with Perry type buckling curves. Numerical models were developed to investigate effects of various parameters on column strength and to develop full column curves. It was observed that material nonlinearity significantly influence column strengths, and hence, different column curves were developed for a total of 20 material property combinations by calibrating imperfection factor and limiting slenderness ratio for each set. Proposed method includes the strain hardening benefits for stocky section, and abolished the necessity of calculating effective cross-sectional properties for slender sections. Performance of the proposed technique is compared against those obtained by the Eurocode EN1993-1-4.


Author(s):  
Shameem Ahmed ◽  
Mahmud Ashraf

The Continuous Strength Method (CSM) is a new strain based design approach developed for nonlinear metallic materials, and has recently been successfully used for stocky stainless steel sections for which the benefit of strain hardening is more pronounced. Typically available stainless steel cross-sections are quite slender, and their failure is dominated by local plate buckling before yielding showing significant post buckling, which does not allow the definition of cross-section deformation capacity currently adopted in CSM. In this paper, a concept of equivalent elastic deformation capacity is introduced for slender sections, and the scope of CSM is extended to predict capacities for slender cross-sections under compression. Design guidelines are proposed to calculate equivalent elastic deformation capacities for various cross-section types using the current knowledge of CSM, which is used to predict the ultimate section capacity when subjected to compression. The proposed rules are verified against all available test results, and are found to in good agreement with experimental evidence.


Author(s):  
Yoshiyasu Ito ◽  
Akira Tsuruoka ◽  
Yoshiyuki Waki ◽  
Hiroko Osedo

In case of fire occurring in an Oil and Gas facility, pressurized vessels may be exposed to fire. Though the entire system will be depressurized once a fire is detected, vessels may rupture, leading to risk of flammable, toxic or cryogenic fluid being released. Therefore, pressure vessels should be designed to withstand internal pressure without rupture in fire situations, at least until the system pressure can be decreased to a safe level. A pressure vessel rupture study should be conducted in addition to design code calculation to ensure a safe design in case of fire. As part of the recent trend for safer plant design, demand for pressure vessel rupture studies is growing. In our previous presentation (PVP2015-45260 [1]), the material data for carbon steel (SA-516 Gr.70) and stainless steel (SA240 SUS type304 and SUS type304L) at the high temperature range were obtained by material testing and presented as our study result. For the present research, pressure vessel rupture studies were performed for carbon steel and stainless steel using FEM analysis and calculation methods in published design guidelines for various conditions (e.g. heating area and shell thickness, etc.). In conclusion, a procedure for pressure vessel rupture study is proposed.


2017 ◽  
Vol 11 (1) ◽  
pp. 358-368 ◽  
Author(s):  
Michal Jandera ◽  
Denny Syamsuddin ◽  
Bretislav Zidlicky

There are several methods for considering the interaction between compression and bending for slender steel members. This is covered by the interaction formula and the general method, currently. For stainless steel, the structural design standards have been developed largely in-line and refer to carbon steel design guidelines. The current stainless steel interaction formula of axial force and bending moment given in EN 1993-1-4 was derived on limited results available. On the other hand, the general method may be used without any change for stainless steel according to the Eurocode despite the non-linear stress-strain behaviour, which obviously could lead to some drawbacks. Hence, the main objective of this paper is to compare the analysis results with existing Eurocode design formulas, the general method and some formula taken from experimental and parametric studies, showing their possible applicability, weaknesses and the need of further development. The conclusions are not applicable for stainless steel only, but they may be used for other non-linear materials such as aluminium alloys to some extent.


Author(s):  
Nuno Lopes ◽  
Pedro Gamelas ◽  
Paulo Vila Real

For predicting the behaviour of beams with thin-walled I sections, named Class 4 in Eurocode 3 (EC3), it is necessary to account for the occurrence of both local and lateral torsional buckling (LTB). These instability phenomena, which are intensified at elevated temperatures, should be accurately considered in design rules. The fire design guidelines for stainless steel members, given in Part 1-2 of EC3, propose the use of the same formulae developed for carbon steel (CS) elements. However, these two materials have different constitutive laws, leading to believe that the use of those formulae should be validated. This work presents a parametric numerical study on the behaviour of stainless steel beams with Class 4 I sections at elevated temperatures. The influences of several parameters such as stainless steel grade, loading type and cross section slenderness are evaluated, and comparisons between the obtained numerical results and EC3 rules are presented.


Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.


Author(s):  
J. A. Korbonski ◽  
L. E. Murr

Comparison of recovery rates in materials deformed by a unidimensional and two dimensional strains at strain rates in excess of 104 sec.−1 was performed on AISI 304 Stainless Steel. A number of unidirectionally strained foil samples were deformed by shock waves at graduated pressure levels as described by Murr and Grace. The two dimensionally strained foil samples were obtained from radially expanded cylinders by a constant shock pressure pulse and graduated strain as described by Foitz, et al.


Author(s):  
R. Gonzalez ◽  
L. Bru

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.


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