scholarly journals Numerical Simulation and Design Recommendations for Web Crippling Strength of Cold-Formed Steel Channels with Web Holes under Interior-One-Flange Loading at Elevated Temperatures

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 666
Author(s):  
Zhiyuan Fang ◽  
Krishanu Roy ◽  
Hao Liang ◽  
Keerthan Poologanathan ◽  
Kushal Ghosh ◽  
...  
Keyword(s):  
Parametric Analysis ◽  
Elevated Temperatures ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Hole Size ◽  
Strength Reduction Factor ◽  
Web Crippling ◽  
Study Results ◽  
Cold Formed Steel ◽  
The Web

This paper investigates the interior-one-flange web crippling strength of cold-formed steel channels at elevated temperatures. The stress-strain curves of G250 and G450 grade cold-formed steel (CFS) channels at ambient and elevated temperatures were taken from the literature and the temperatures were varied from 20 to 700 °C. A detailed parametric analysis comprising 3474 validated finite element models was undertaken to investigate the effects of web holes and bearing length on the web crippling behavior of these channels at elevated temperatures. From the parametric study results, it was found that the web crippling strength reduction factor is sensitive to the changes of the hole size, hole location, and the bearing length, with the parameters of hole size and hole location having the largest effect on the web crippling reduction factor. However, the web crippling strength reduction factor remains stable when the temperature is changed from 20 to 700 °C. Based on the parametric analysis results, the web crippling strength reduction factors for both ambient and elevated temperatures are proposed, which outperformed the equations available in the literature and in the design guidelines of American standard (AISI S100-16) and Australian/New Zealand standard (AS/NZS 4600:2018) for ambient temperatures. Then, a reliability analysis was conducted, the results of which showed that the proposed design equations could closely predict the reduced web crippling strength of CFS channel sections under interior-one-flange loading conditions at elevated temperatures.

scholarly journals FINITE ELEMENT ANALYSIS OF UNFASTENED COLD-FORMED STEEL CHANNEL SECTIONS WITH WEB HOLES UNDER END-TWO-FLANGE LOADING AT ELEVATED TEMPERATURES

2021 ◽  
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Reduction Factor ◽  
Strength Reduction Factor ◽  
Element Analysis ◽  
Study Results ◽  
Cold Formed Steel ◽  
Factor Equation

This paper presents the results of a finite element investigation on cold-formed steel (CFS) channel sections with circular web holes under end-two-flange (ETF) loading condition and subjected to elevated temperatures. The stress strain curve for G250 CFS with 1.95 mm thickness at elevated temperatures was taken from Kankanamge and Mahendran and the temperatures were considered up to 700 oC. To analyse the effect of web hole size and bearing length on the strength of such sections at elevated temperatures, a parametric study involving a total of 288 FE models was performed. The parametric study results were then used to assess the applicability of the strength reduction factor equation presented by Uzzaman et al. for CFS channel-sections with web holes under ETF loading from ambient temperature to elevated temperatures. It is shown that the reduction factor equation is safe and reliable at elevated temperatures.

scholarly journals Design of cold-formed stainless steel lipped channel sections with web openings subjected to web crippling under end-one-flange loading condition

2016 ◽  
Vol 20 (7) ◽  
pp. 1024-1045 ◽  
Author(s):  
Amir M Yousefi ◽  
James BP Lim ◽  
Asraf Uzzaman ◽  
Ying Lian ◽  
G Charles Clifton ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Loading Condition ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Web Openings ◽  
Web Crippling ◽  
Steel Grades ◽  
The Web

This article presents a numerical investigation on the web crippling strength of cold-formed stainless steel lipped channel sections with circular web openings under end-one-flange loading condition. In order to take into account the influence of the circular web openings, a parametric study involving 1992 finite element analyses was performed, covering duplex EN1.4462, austenitic EN1.4404 and ferritic EN1.4003 stainless steel grades; from the results of the parametric study, strength reduction factor equations are proposed. The web crippling strengths predicted by the reduction factor equations are first compared to the strengths calculated using the equations recently proposed for cold-formed carbon steel lipped channel sections. It is demonstrated that the strength reduction factor equations proposed for cold-formed carbon steel are unconservative for the stainless steel grades by up to 7%. Unified strength reduction factor equations are then proposed that can be applied to all three stainless steel grades.

Joint strength reduction factor of internally ring-stiffened tubular joints at elevated temperatures

2016 ◽  
Vol 19 (10) ◽  
pp. 1650-1660 ◽  
Author(s):  
Xiaoyi Lan ◽  
Fan Wang ◽  
Zhifeng Luo ◽  
Dingding Liu ◽  
Chen Ning ◽  
...  
Keyword(s):  
Joint Strength ◽  
Elevated Temperatures ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Tubular Joints

Evaluation Method of Creep-Fatigue Life for 316FR Weldment

2015 ◽  
Author(s):  
Yuji Nagae ◽  
Kenji Yamamoto ◽  
Tomomi Otani
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Fatigue Life ◽  
Base Metal ◽  
Evaluation Method ◽  
Elevated Temperatures ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Creep Fatigue

The most important failure mode to be prevented is creep-fatigue at elevated temperatures in fast reactors. 316FR stainless steel is a candidate material for the reactor vessel and internal structures. A method to evaluate creep-fatigue life, based on the time fraction rule, has been already developed in base metal of 316FR stainless steel. Development of procedure in evaluating creep-fatigue life is also necessary for the weldment of 316FR stainless steel by similar fillers or 16-8-2 fillers. Compared between mechanical properties of weldment and those of base metal, strength-reduction factors for weldment have been evaluated. Strength-reduction factor for fatigue has been proposed. It is considered that strength-reduction factor for creep strength is not necessary. Creepfatigue life could be evaluated in the same way for weldments of similar fillers and 16-8-2 fillers, because a difference in mechanical properties between both filler metals is negligible. Creep-fatigue life by the time fraction rule using analytical relaxation curve for weldments were compared with experimental data, and a method to evaluate creep-fatigue life for the weldments of 316FR stainless steel has been proposed.

Influence of Wear Properties on Fretting Fatigue Life of a CK45 Alloy and the Al7175 Alloy

2008 ◽  
Vol 587-588 ◽  
pp. 971-975 ◽  
Author(s):  
M. Buciumeanu ◽  
A.S. Miranda ◽  
F.S. Silva
Keyword(s):  
Wear Resistance ◽  
Fatigue Life ◽  
Material Properties ◽  
Fatigue Behavior ◽  
Synergetic Effect ◽  
Fretting Fatigue ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
Wear Properties

The main objective of this work was to study the influence of the wear properties of two commercial alloys (CK45 and Al7175) on their fretting fatigue behavior. It is verified the effect of material local degradation by wear on a fatigue strength reduction factor, namely the stress concentration factor, and on the overall fretting fatigue life of these materials. The fretting fatigue phenomenon is a synergetic effect between wear and fatigue. It is dependent on both the fatigue and the wear properties of the materials. Material properties promoting an increase in wear resistance should enhance fretting fatigue life.

Design of Pressure Vessels for Low-Cycle Fatigue

1962 ◽  
Vol 84 (3) ◽  
pp. 389-399 ◽  
Author(s):  
B. F. Langer
Keyword(s):  
Fatigue Strength ◽  
Pressure Vessel ◽  
Low Cycle Fatigue ◽  
Fatigue Curve ◽  
Pressure Vessels ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Strength Reduction Factor ◽  
The Mean ◽  
Fatigue Evaluation

Methods are described for constructing a fatigue curve based on strain-fatigue data for use in pressure vessel design. When this curve is used, the same fatigue strength-reduction factor should be used for low-cycle as for high-cycle conditions. When evaluating the effects of combined mean and alternating stress, the fatigue strength-reduction factor should be applied to both the mean and the alternating component, but then account must be taken of the reduction in mean stress which can be produced by yielding. The complete fatigue evaluation of a pressure vessel can be a major task for the designer, but it can be omitted, or at least drastically reduced, if certain requirements can be met regarding design details, inspection, and magnitude of transients. Although the emphasis in this paper is on pressure vessel design, the same principles could be applied to any structure made of ductile metal and subjected to limited numbers of load cycles.

Strength reduction factor of self-centering structures under near-fault pulse-like ground motions

2020 ◽  
Vol 24 (1) ◽  
pp. 119-133
Author(s):  
Huihui Dong ◽  
Qiang Han ◽  
Xiuli Du ◽  
Canxing Qiu
Keyword(s):  
Ground Motions ◽  
Time History ◽  
Reduction Factor ◽  
Strength Reduction ◽  
The Self ◽  
Hysteretic Behavior ◽  
Hysteretic Model ◽  
Strength Reduction Factor ◽  
Vibration Period ◽  
Near Fault

Many studies on the strength reduction factor mainly focused on structures with the conventional hysteretic models. However, for the self-centering structure with the typical flag-shaped hysteretic behavior, the corresponding study is limited. The main purpose of this study is to investigate the strength reduction factor of the self-centering structure with flag-shaped hysteretic behavior subjected to near-fault pulse-like ground motions by the time history analysis. For this purpose, the smooth flag-shaped model based on Bouc-Wen model which can show flag-shaped hysteretic behavior is first described. The strength reduction factor spectra of the flag-shaped model are then calculated under 85 near-fault pulse-like ground motions. The influences of the ductility level, vibration period, site condition, hysteretic parameter, and hysteretic model are investigated statistically. For comparison, the strength reduction factors under ordinary ground motions are also analyzed. The results show that the strength reduction factor from near-fault pulse-like ground motions is smaller. Finally, a predictive model is proposed to estimate the strength reduction factor for the self-centering structure with the flag-shaped model under near-fault pulse-like ground motions.

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