Simplified Method for Elastic Distortional Buckling Stress of Cold-Formed Thin-Wall Steel Members

2012 ◽  
Vol 166-169 ◽  
pp. 3391-3398
Author(s):  
Yang Zhao ◽  
Wei Ming Yan ◽  
Cheng Yu
Keyword(s):  
Technical Specification ◽  
Effective Area ◽  
Thin Wall ◽  
Steel Buildings ◽  
Distortional Buckling ◽  
The North ◽  
Buckling Stress ◽  
Steel Members ◽  
Calculation Results ◽  
Similar Computation

For the distortional buckling of cold-formed thin-wall steel members, the Direct Strength Method (DSM) is a recently adopted design approach by foreign standard, and Chinese professional standard Technical specification for low-rise cold-formed thin-wall steel buildings present the calculation formulas based on the Effective Area Method (EAM) .The key of both methods is the elastic distortional buckling stress .At present, the calculation methods about it are over conservative .Compare the calculation results of method in AISI S100with the one calculated by software CUFSM ,for C and Z sections in bending and axial compression loading respectively in the North American Specifications for Cold-Formed Steel Structural Members (AISI S100). This paper presents revised simplified methods for calculating the elastic distortional buckling stress. The new methods yield more accurate results but similar computation cost compared to the existing methods.

Comparison on Calculation Method for Post-Buckling Strength of Thin-Webbed I-Shape Member

2014 ◽  
Vol 501-504 ◽  
pp. 620-623
Author(s):  
Xing You Yao ◽  
Yan Li Guo ◽  
Kai Liu
Keyword(s):  
Calculation Method ◽  
Slenderness Ratio ◽  
Steel Structures ◽  
Effective Area ◽  
Thickness Ratio ◽  
Estimation Methods ◽  
Thin Wall ◽  
Steel Buildings ◽  
Buckling Strength ◽  
Post Buckling

The thin-webbed I-shaped members are used as the basic members for beams and columns of steel buildings in order to increase utilization ratio of steel. The local buckling can occur for these members because of the large width-thickness ratio and these members have a substantial post-buckling strength which can be used. Different codes in China have different estimation method for substantial post-buckling strength of thin-webbed I-shaped members. So it is very necessary to establish the same calculation method to consider post-buckling strength for different china codes. In this paper the effective width estimation methods of technical specification for steel structure of light weight buildings with gabled frames (CECS 102-2002), code for design of steel structures (GB50017-2003), technical code of cold-formed thin-wall steel structures (GB50018-2002), America specification (AISC: 2005), European specification (E3-1.5:2006), and Winter equation are introduced simply. The effective area of thin-webbed I-shaped members with different width-thickness ratio in web and slenderness ratio are estimated using these codes. Comparison of these estimated results show that CECS 102-2002, GB50017-2003, AISC: 2005, Winter equation, and E3-1.5:2006 may be conservative or unsafe for members with different slenderness ratio or width-thickness ratio of web. GB50018-2002 is applicable for members with different slenderness ratio or width-thickness ratio of web without considering interaction between flange and web of members and can be used to estimate the effective area of thin-webbed I-shaped members. At the same time, the calculated method of post-buckling strength of thin-webbed I-shaped members in CECS 102-2002 and GB50017-2003 could use the same method as GB50018-2002.

Simulation of the Residual Stress of Cold-Formed Thin-Wall Steel Members and Calculation of Load under Its Influence

2005 ◽  
Vol 490-491 ◽  
pp. 112-117
Author(s):  
Feng Zhao ◽  
Hua Chen Liu
Keyword(s):  
Residual Stress ◽  
Initial Stress ◽  
Technical Specification ◽  
Steel Structures ◽  
Thin Wall ◽  
Integral Points ◽  
Elastic Plastic ◽  
Steel Members ◽  
Specific Object ◽  
Set Up

Because of the particularity of distribution of the residual stress of cold-formed thin-wall steel members, now there has not yet been a proper method for directly considering the influence of the residual stress in calculating the reliable capacity of carrying load of cold-formed thin-wall steel members, and such is the typical case in China’s National Technical Specification of Cold-formed Thin-wall Steel Structures GB50018-2002. With the cold-formed thin-wall channel steel taken as specific object in this study as well as assumed to be ideal elastic-plastic body, their finite modular models are set up in ANSYS. According to the tested results and the distributing rules of residual stress, the models of the residual stress of cold-formed thin-wall channel steel are established close to the factual data, and also the initial stress file is set up that can describe the magnitude and distribution of the residual stress. The file has two features: first, it is likely to find out about the rules of the cold-steel residual stress varying in the direction of thickness by using the values of residual stress at some integral points in thickness direction of a specified module , and second, it is applicabled to simulate various distributions of residual stress. So the ultimate load of the member can be worked out and elastic-plastic calculating problem of cold-formed thin-walled steel sections can be easily solved by introducing the initial stress file into the stability analysis of ANSYS.

EWM-based design method for distortional buckling of cold-formed thin-walled lipped channel sections with holes

2022 ◽  
Vol 19 (1) ◽  
pp. 972-996
Author(s):  
Xingyou Yao ◽  
Keyword(s):  
Design Method ◽  
Effective Width ◽  
The Finite Element Method ◽  
Distortional Buckling ◽  
Buckling Strength ◽  
Channel Section ◽  
The North ◽  
Buckling Stress ◽  
Cold Formed Steel ◽  
Theoretical And Numerical Analysis

<abstract> <p>The distortional buckling is easy to occur for the cold-formed steel (CFS) lipped channel sections with holes. There is no design provision about effective width method (EWM) to predict the distortional buckling strength of CFS lipped channel sections with holes in China. His aim of this paper is to present an proposal of effective width method for the distortional buckling strength of CFS lipped channel sections with holes based on theoretical and numerical analysis on the partially stiffened element and CFS lipped channel section with holes. Firstly, the prediction methods for the distortional buckling stress and distortional buckling coefficients of CFS lipped channel sections with holes were developed based on the energy method and simplified rotation restrained stiffness. The accuracy of the proposed method for distortional buckling stress was verified by using the finite element method. Then the modified EWM was proposed to calculate the distortional buckling strength and the capacity of the interaction buckling of CFS lipped channel sections with holes based on the proposal of distortional buckling coefficient. Finally, comparisons on ultimate capacities of CFS lipped channel sections with holes of the calculated results by using the modified effective width method with 347 experimental results and 1598 numerical results indicated that the proposed EWM is reasonable and has a high accuracy and reliability for predicting the ultimate capacities of CFS lipped channel section with holes. Meanwhile, the predictions by the North America specification are slightly unconservative.</p> </abstract>

scholarly journals Geological region by multi-signal method of gravity anomaly data in central Vietnam area

2021 ◽  
Vol 62 (5) ◽  
pp. 43-54
Author(s):  
Hong Thi Phan ◽  
Petrov Aleksey Vladimirovich ◽  
Phuong Minh Do ◽  
Luu Truong Nguyen ◽  
Keyword(s):  
Central Area ◽  
Tectonic Activity ◽  
Horizontal Gradient ◽  
Spectral Correlation ◽  
Sliding Windows ◽  
The North ◽  
Central Vietnam ◽  
Two Dimensional Filtering ◽  
Calculation Results ◽  
Signal Method

This paper presents the research results of applying the combined method of probabilistic statistical approaches, energy density spectral correlation, two-dimensional filtering in dynamic sliding windows, full horizontal gradient and heterogeneous axis tracking method to process and interpret the Bughe gravitational anomaly field in central area Vietnam. The calculation results have shown the superiority of the twodimensional filter in dynamic sliding windows compared to the filters in fixed windows in GEOSOFT software, GMT software. According to the physical characteristics of the field, the study area was divided into 13 homogeneous classes, this result is consistent with the geological-tectonic data in the area. In the north and northeast, the stabilized rock layers are characterized by homogeneous layers that extend in the northwestsoutheast direction. In the south and southwest, there is complex tectonic activity characterized by high density rock layers overlain by low density rock layers in each fault band with different directions of development. This suggests that there may be deeply buried mineral deposits of magmatic origin in central area Vietnam.

scholarly journals Evaluasi Kinerja Apill dan Geometrik Simpang 3 Sungai Bengkel Kota Bengkalis

2021 ◽  
Vol 18 (2) ◽  
pp. 197-206
Author(s):  
Nursafika Syafika ◽  
Muhammad Idham
Keyword(s):  
Cycle Time ◽  
Slow Motion ◽  
Public Works ◽  
Degree Of Saturation ◽  
Traffic Light ◽  
Traffic Jam ◽  
The North ◽  
Calculation Results ◽  
Bottle Neck ◽  
Intersection Geometry

Third junction of Sungai Bengkel was a Signalized Intersection which a hasn’t have traffic jam ,which has three approach, are North approach, West approach and East approach. However, the alinyemen for the North approach has problems that make it difficult for vehicles, especially four-wheelers to turn because the effect bottle neck resulting in the slow motion of the vehicle and change of phase time . the problem solving, the evalution of traffic light and intersection geometry were carried out by widening  the alinyemen for the North approach and East approaches and doing changes in cycle time. The purpose of evaluating the performance of traffic light and Geometrics at the third intersection of Sungai Bengkel is to determine the value of the degree of saturation and to know the performance of the intersection.At the intersection planning, it refers to the PKJI 2014 for Intersection Performance, while for the Geometrics it refers to Module 4 of the Ministry of Public Works and Public Housing on Geometric Planning of Plane Intersections.Based on  the calculation results of the Sungai Bengkel junction performance indicate that, the degree of  saturation  < 0.85,which is 0.529 for North,  0.537 for East, and 0.570  for West .With the radius is 15 m, and the cycle  time of traffic light 50 second, with the delay time  as long as 17 second/pcu

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