scholarly journals A Generalized Approach to Estimating the Out-of-plane Buckling of Steel Sections with a Triangularly Corrugated Web

2021 ◽  
Vol 1066 (1) ◽  
pp. 012002
Author(s):  
Sergey Kudryavtsev
2013 ◽  
Vol 12 (2) ◽  
pp. 229-236
Author(s):  
Mariusz Maślak ◽  
Krzysztof Kuchta ◽  
Marcin Łukacz

More accurate design algorithm helpful in bending resistance evaluation of steel beams with corrugated web exposed to fully developed fire is presented and discussed in detail. The condition of fire resistance limit state is proposed to be determined by the interactive formula based on the consideration of biaxial bending in which the transverse out-of-plane bending phenomenon is the spatial effect of in-plane shear. Such an influence, usually neglected in formal models dealing with the persistent design situation, can become more significant under fire conditions, when the steel yield point decreases as a consequence of the flanges temperature growth. Dependence between the material temperature and the global instability factors is considered in the methodology proposed by the authors, especially with relation to the assessment of the adequate values of lateral – torsional buckling coefficient as well as of flexural transverse buckling coefficient specified for the compressed flange. The conclusive safety condition should be supplemented by the additional interactive component in which the influence of the axial compression force is expressed, in the case when such internal force is induced in a considered beam as a result of thermal strains constrainment.


2021 ◽  
pp. 136943322098609
Author(s):  
Ferhat Erdal ◽  
Osman Tunca ◽  
Serkan Tas ◽  
Ramazan Ozcelik

The structural performance of standard steel sections in long-span constructions gradually deteriorates due to wider and slighter webs that tend to buckle. This is the characteristic problem of plane webs. Corrugated steel web plates allow a considerable reduction of weight and increasing the web capacity of the beam. The experimental test results of optimal designed corrugated web beams, fortifying thin-walled steel girders without stiffeners, under load conditions, have been compared with the 3-D plane strains finite elements ( FE) model in this paper. The span of fabricated corrugated web beams ( CWB) is chosen as 5 m. These optimally designed CWB are exposed to a single concentrated loading, two-point loading, and partially distributed loading, respectively. The design methods for CWB are firefly optimization and hunting search algorithms. The implementation of design constraints is based on the EUROCODE, DIN, and DAST-Ri. 015 code provisions. The load-displacement curves, the residual load capacity, and the failure form of eighteen tested corrugated web beams are inquired in depth along the experimental process. The structural analysis software ANSYS is used for the simulation of the experimental study, the verification of all test results, and the investigation of the behavior of failure forms.


1987 ◽  
Vol 14 (4) ◽  
pp. 550-558 ◽  
Author(s):  
K.S. Sivakumaran

Load tests were carried out on 48 stub column specimens of cold-formed steel sections having flat widths of 82.5 and 144.7 mm, thicknesses of 1.60 and 1.29 mm, respectively, and various sizes and shapes of holes punched through their webs. This paper summarizes the experimental local buckling loads, ultimate loads, load–axial shortening relationships, and load–out-of-plane deflection relationships of the above specimens. Presently, the Canadian design code does not include any provisions in regards to the design of perforated cold-formed sections, owing to the lack of experimental results. A design approach using the present code "effective design width" for unstiffened elements is explored and the observations resulting from the comparison between the calculated values and the experimental values are given. The new American Iron and Steel Institute design specification gives an effective design width for cold-formed section with circular perforations. The appropriateness of this equation when applied to circular, square, and elongated openings is discussed. It appears that the design provisions of both codes are inadequate for the design of perforated cold-formed steel sections and further research is needed in this area. This is essential, considering the fact that, in practice, the cold-formed members often contain prepunched holes. Key words: axial load, buckling, building codes, cold-formed steel, effective design width, perforation, ultimate loads.


Author(s):  
G.A. Bertero ◽  
R. Sinclair

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.


2020 ◽  
Vol 0 (7) ◽  
pp. 45-56
Author(s):  
Lyudmila Lavrinenko ◽  
Danylo Oliinyk

2003 ◽  
Vol 779 ◽  
Author(s):  
David Christopher ◽  
Steven Kenny ◽  
Roger Smith ◽  
Asta Richter ◽  
Bodo Wolf ◽  
...  

AbstractThe pile up patterns arising in nanoindentation are shown to be indicative of the sample crystal symmetry. To explain and interpret these patterns, complementary molecular dynamics simulations and experiments have been performed to determine the atomistic mechanisms of the nanoindentation process in single crystal Fe{110}. The simulations show that dislocation loops start from the tip and end on the crystal surface propagating outwards along the four in-plane <111> directions. These loops carry material away from the indenter and form bumps on the surface along these directions separated from the piled-up material around the indenter hole. Atoms also move in the two out-of-plane <111> directions causing propagation of subsurface defects and pile-up around the hole. This finding is confirmed by scanning force microscopy mapping of the imprint, the piling-up pattern proving a suitable indicator of the surface crystallography. Experimental force-depth curves over the depth range of a few nanometers do not appear smooth and show distinct pop-ins. On the sub-nanometer scale these pop-ins are also visible in the simulation curves and occur as a result of the initiation of the dislocation loops from the tip.


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