scholarly journals STRENGTH AND BEHAVIOR OF ELASTIC DISTORTIONAL BUCKLING FOR COLD-FORMED CHANNEL MEMBER UNDER COMPRESSION

2022 ◽  
Vol 87 (791) ◽  
pp. 139-148
Author(s):  
Kazuya MITSUI ◽  
Kikuo IKARASHI ◽  
Tomoki KOBASHI ◽  
Ryohei KUWADA
2013 ◽  
Vol 671-674 ◽  
pp. 461-464
Author(s):  
Chun Gang Wang ◽  
Run Jia Liang ◽  
Lian Guang Jia ◽  
Hong Liu

This paper presents an experimental investigation and a numerical analysis on the bending strength and behavior of cold-formed steel C-section and ∑-section beams with complex edge stiffeners and web holes. Local buckling, distortional buckling and interaction between local and distortional buckling were observed in the tests. The experimental results show that the stiffened web has great influence on member's bending strength. Compared with C-section specimens, the stiffness of the web stiffeners of ∑-section specimens reduced the influence of the holes. The finite element analysis results show good agreement with the experimental results in terms of bending strength and buckling mode.


2010 ◽  
Vol 163-167 ◽  
pp. 90-101 ◽  
Author(s):  
Xing You Yao ◽  
Yuan Qi Li ◽  
Zu Yan Shen

Distortional buckling may occur for Cold-formed thin-walled steel lipped channel member except local buckling and overall buckling. The buckling of flange and lip are the important factor for the occurrence the distortional buckling. The different design codes have different design method for calculating plate buckling coefficient of flange and lip using the effective width method. So the effective width method in different codes are introduced and the load-carrying capacities of 100 lipped channel section compressive members collected from reference are computed using ‘Cold-formed steel structures (AS/NZS 4600:2005)’, ‘Supplementary rules for cold-formed members and sheeting(EN1993-1-3:2006)’, ‘North American specification for the design of cold-formed steel Structural Members(AISI-S100:2007)’, ‘Specification for the design of cold-formed steel structural members (AISI:1996)’ and ‘Technical code of cold-formed thin-walled steel structures’(GB50018-2002). The calculated results show that ‘Technical code of cold-formed thin-walled steel structures (GB50018-2002)’ and ‘Supplementary rules for cold-formed members and sheeting (EN1993-1-3:2006)’ are conservative and ‘Cold-formed steel structures (AS/NZS 4600:2005)’, ‘North American specification for the design of cold-formed steel Structural Members (AISI-S100:2007)’ and ‘Specification for the design of cold-formed steel structural members (AISI:1996)’ are unsafe. The elastic buckling stress of different lipped channel sections are predicted by finite strip program (CUFSM) and get the suggested calculation formula of plate buckling coefficient of flange according to regression Analysis. The calculated results using suggested plate buckling coefficient of flange are agree to test results.


2013 ◽  
Vol 353-356 ◽  
pp. 2313-2318 ◽  
Author(s):  
Qi Jie Ma ◽  
Pei Jun Wang ◽  
Quan Huang

The fire resistant behavior of web-slotted cold-formed channel columns with non-uniform temperature distributions was investigated extensively by use of the finite element method in this article. The failure mode of the web-slotted column with non-uniform temperature distributions is very complex with the interaction of the local buckling, the distortional buckling and the global flexural buckling. The ultimate strengths of members with non-uniform temperature distributions are higher than that with uniform temperature distributions of the same highest temperature. In addition the analysis results indicate that the degradation of the material strength makes the dominating factor influencing the fire resistance of cold-formed members. The simplified approach was proposed for the practical design of web-slotted cold-formed columns at high temperatures.


2018 ◽  
Vol 41 ◽  
Author(s):  
Peter DeScioli

AbstractThe target article by Boyer & Petersen (B&P) contributes a vital message: that people have folk economic theories that shape their thoughts and behavior in the marketplace. This message is all the more important because, in the history of economic thought, Homo economicus was increasingly stripped of mental capacities. Intuitive theories can help restore the mind of Homo economicus.


2019 ◽  
Vol 42 ◽  
Author(s):  
Jeffrey R. Alberts ◽  
Christopher Harshaw ◽  
Gregory E. Demas ◽  
Cara L. Wellman ◽  
Ardythe L. Morrow

Abstract We identify the significance and typical requirements of developmental analyses of the microbiome-gut-brain (MGB) in parents, offspring, and parent-offspring relations, which have particular importance for neurobehavioral outcomes in mammalian species, including humans. We call for a focus on behavioral measures of social-emotional function. Methodological approaches to interpreting relations between the microbiota and behavior are discussed.


Author(s):  
N. David Theodore ◽  
Mamoru Tomozane ◽  
Ming Liaw

There is extensive interest in SiGe for use in heterojunction bipolar transistors. SiGe/Si superlattices are also of interest because of their potential for use in infrared detectors and field-effect transistors. The processing required for these materials is quite compatible with existing silicon technology. However, before SiGe can be used extensively for devices, there is a need to understand and then control the origin and behavior of defects in the materials. The present study was aimed at investigating the structural quality of, and the behavior of defects in, graded SiGe layers grown by chemical vapor deposition (CVD).The structures investigated in this study consisted of Si1-xGex[x=0.16]/Si1-xGex[x= 0.14, 0.13, 0.12, 0.10, 0.09, 0.07, 0.05, 0.04, 0.005, 0]/epi-Si/substrate heterolayers grown by CVD. The Si1-xGex layers were isochronally grown [t = 0.4 minutes per layer], with gas-flow rates being adjusted to control composition. Cross-section TEM specimens were prepared in the 110 geometry. These were then analyzed using two-beam bright-field, dark-field and weak-beam images. A JEOL JEM 200CX transmission electron microscope was used, operating at 200 kV.


Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.


2012 ◽  
Vol 13 (4) ◽  
pp. 111-119 ◽  
Author(s):  
Alexandra Hollo

Language development is the foundation for competence in social, emotional, behavioral, and academic performance. Although language impairment (LI) is known to co-occur with behavioral and mental health problems, LI is likely to be overlooked in school-age children with emotional and behavioral disorders (EBD; Hollo, Wehby, & Oliver, in press). Because language deficits may contribute to the problem behavior and poor social development characteristic of children with EBD, the consequences of an undiagnosed language disorder can be devastating. Implications include the need to train school professionals to recognize communication deficits. Further, it is critically important that specialists collaborate to provide linguistic and behavioral support for students with EBD and LI.


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