Problems of Cold-Bent Notched C-Shaped Profile Members

2014 ◽  
Vol 941-944 ◽  
pp. 1871-1875 ◽  
Author(s):  
Nikolay I. Vatin ◽  
Tatiana Nazmeeva ◽  
Roman Guslinscky

Nowadays cold bent steel thermal сold-bent С-profile is widely used in building construction but we still have some little studied questions in the fields of thermal conductivity, air permeability, resistibility and corrosion behavior of the profile. Cold-bent notched С-profile is used for interior exterior panel members. Lengthwise notches made chequerwise in the profile walls increase the distance of heat flow and decrease heat conductivity and eliminate cold bridges that is why the profile is called “thermal profile”. Cold-bent profile made by cold bending requires alternate approach when engineering structures are designed and maintained. The approach means thin walls’ and the profile special form’ impact on the bearing capacity and stability of the structures should be taken into account. In spite of the wide use of cold-bent notched C-profile in building frameworks, we see lack of information on how the notches influence the bearing capacity and stability of structures. There are no official normative documents on calculation and designing of cold-bent notched profile structures. We carry out theoretical and experimental investigations on global buckling and bearing capacity of steel members of C-shaped notched profiles of different cross-sections area. We carry out theoretical and experimental investigations on heat current passing through the thermal profile structure is held with the use of testing bed.

2019 ◽  
Vol 29 (4) ◽  
pp. 141-148 ◽  
Author(s):  
Krzysztof Wierzbicki ◽  
Maciej Szumigała

Abstract The article analyses the method of enhancing a steel beam by adding additional steel members like ribs. They are rigidly connected with both flanges in a plane parallel to the web. That plates reduces warping during in-plane bending of steel beam under lateral-torsional bucking. Different thicknesses of steel plates used as ribs and different cross-sections were taken into account. Calculations were conducted using FEM and ABAQUS CAE environment. The outcomes were compared with ones from previous studies which concerned an influence of endplates on load-bearing capacity of an I-beam.


2011 ◽  
Vol 9 (3) ◽  
pp. 367-378
Author(s):  
Miroslav Besevic ◽  
Danijel Kukaras

Analysis of axially compressed steel members made of cold formed profiles presented in this paper was conducted through both experimental and numerical methods. Numerical analysis was conducted by means of "PAK" finite element software designed for nonlinear static and dynamic analysis of structures. Results of numerical analysis included ultimate bearing capacity with corresponding middle section force-deflection graphs and buckling curves. Extensive experimental investigation were also concentrated on determination of bearing capacity and buckling curves. Experiments were conducted on five series with six specimens each for slenderness values of 50, 70, 90, 110 and 120. Compressed simply supported members were analyzed on Amsler Spherical pin support with unique electronical equipment and software. Besides determination of forcedeflection curves, strains were measured in 18 or 12 cross sections along the height of the members. Analysis included comparisons with results obtained by different authors in this field recently published in international journals. Special attention was dedicated to experiments conducted on high strength and stainless steel members.


2011 ◽  
Vol 243-249 ◽  
pp. 584-591
Author(s):  
Long Yu Yang ◽  
Zheng Liang Li

The built-up cruciform section formed by two equal-leg angles has been widely applied in extra high voltage(EHV) transmission towers, however, domestic codes provide structure requirement and overlook the influence of multi filler plates to members’ bearing capacity. For the purpose of this, a pin end experiment covering 3 different cross sections(Q420, L160*12, L160*14 and L160*16) and 7 different slendernesses(25~55) has been run. This experiment contains totally 21 specimens. Furthermore, large amounts of models have been analysis by finite element method whose parameters contain variety b/t, λ, filler plate intervals and forms, amount of bolts in filler plate. A recommended formula is given for evaluating the influence of filler plates. The results show: multi filler plates enhance bearing capacity slightly for members with λ less than 35, and the better interval for filler plates is 10i-40i(i is the minimal radius of gyration); filler plates do not work well when b/t of the member is extreme large or small, a propositional b/t range for this kind of member is 11-16; the amount of bolts in filler plate has tiny influence on members’ bearing capacity; the recommended formula is applicable and feasible for design.


2018 ◽  
Vol 21 (12) ◽  
pp. 1911-1922
Author(s):  
Yang Zhan ◽  
Gang Wu

This article proposes a new closed-form equation to determine the reduction factor for global buckling of concentrically loaded pultruded fiber-reinforced polymer struts based on the Ayrton–Perry formula and observed initial out-of-straightness of pultruded fiber-reinforced polymer members measured by other researchers, which makes the original solution recommended by Eurocode 3 easy to be used to predict the global buckling loads of doubly symmetric pultruded fiber-reinforced polymer members subjected to axial compression. The influence of the geometric imperfections of pultruded fiber-reinforced polymer profiles is considered in this new closed-form equation. Validation of the solution including the parameter of the reduction factor for global buckling of pultruded fiber-reinforced polymer columns is performed by comparison with published experimental evidence. In addition, compared with the five closed-form solutions available in the literature, this solution exhibits higher accuracy in predicting the global buckling capacity of concentrically loaded pultruded fiber-reinforced polymer struts with doubly symmetric cross sections. The solution implemented into the new reduction factor equation for global buckling of pultruded fiber-reinforced polymer members can be conveniently used by structural engineers at the preliminary engineering design stage for accurately assessing the reliability and safety of composite structures under concentric compressive loading.


2014 ◽  
Vol 919-921 ◽  
pp. 1794-1800
Author(s):  
Xin Zhi Zheng ◽  
Xin Hua Zheng

Abstract: 7 square steel tubular columns were tested to discuss the ultimate axial bearing capacity, ductility performance and the steel consumption under stiffened by steel belts and binding bars of different cross-sections. Test results indicate that only by increasing fewer amounts of steel usage, stiffened square CFST columns with binding bars can not only improve the overall effects of restraint and alleviate regional local buckling between the binding bars, but also improve the bearing capacity of concrete filled square steel tubular columns. The utility benefits and the economical benefit is considerable, deserving extensive use.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xibing Hu ◽  
Rui Chen ◽  
Yuxuan Xiang ◽  
Yafang Chen ◽  
Qingshan Li

Steel structures are usually damaged by disasters. According to the influence law of the damage on the elastic modulus of steel obtained by the mechanical test of damaged steel, the average elastic moduli of H-section steel members were analyzed. The equations for calculating the average elastic moduli of damaged H-section steel members at different damage degrees were obtained. By using the analytical cross-sectional method, the cross-sectional M-Φ-P relationships and the dimensionless parameter equations of the H-sections in the full-sectional elastic distribution, single-sided plastic distribution, and double-sided plastic distribution were derived. On the basis of the cross-sectional M-Φ-P relationships and dimensionless parameters of actual steel members, the approximate calculation equations for the damaged cross sections were obtained. The Newmark method was used to analyze the deformation of damaged steel columns. Analytical results show good agreement with the test results. The equations and methods proposed in this study have high computational accuracy, and these can be applied to the cross-sectional M-Φ-P relationships and deformation calculation of damaged steel members.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Liuqun Zhao ◽  
Li Zheng ◽  
Hui Qin ◽  
Tiesuo Geng ◽  
Yonggang Tan ◽  
...  

Concrete three-point bending beams with preexisting cracks are widely used to study the growth process of I-II mixed mode cracks. Studying the failure characteristics of preexisting cracks at different locations on concrete three-point bending beams not only has important scientific significance but also has a wide range of engineering application backgrounds in the safety assessment of engineering structures. In this paper, through several numerical experiments, the influence of preexisting cracks at different positions on the failure characteristics of concrete three-point bending beams is studied, and three typical failure modes are obtained. The failure process of the specimens with three typical failure modes is discussed in detail, and it is pointed out that the crack failure mode is tensile failure. The change trends of bearing capacity, acoustic emission quantity, and acoustic emission energy of three typical failure modes are analyzed. The maximum bearing capacity, the maximum acoustic emission quantity, and energy of three failure modes of concrete three-point bending beams generally show an increasing trend.


2019 ◽  
Vol 265 ◽  
pp. 02019
Author(s):  
Sergei Kudriavtcev ◽  
Viacheslav Kovshun

Weak thawing soils around the metal piles pose the main danger when constructing oil pipelines or other engineering structures located in the cryolithozone. The occurrence of ice inside soil causes thermokarst dips and settlement while thawing. High-precision calculations of the load-bearing capacity of soils and accurate forecasts of the amount of thawing in summer are necessary for improving the reliability of engineering structures. Thermopiles are used to prevent thawing of soils around piles and thermally stabilize the permafrost condition. In this article, one of such decisions is considered on the example of oil pipeline along «Kuyumba – Taishet Kozmino» route in Russia. There are permafrost and deformations of the soil body in the base of oil pipeline. The proposed method implies the joint operation of holding soils in frozen state with help of season-cooling devices or thermopiles. It was concluded that special geotechnical engineering for permafrost projects is necessary to avoid the main problems. In order to achieve the goals of the present investigation, the geotechnical software complex «FEM-models» with «Termoground» was used.


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