scholarly journals Analysisof Effective Length Factors of Hinged Pitched-Roof Framed Column with Sway under Arch Effect

2020 ◽  
Vol 165 ◽  
pp. 04069
Author(s):  
Ping Li ◽  
Liping Liu ◽  
Zunli Teng
Keyword(s):  
Order Effect ◽  
Effective Length ◽  
Elastic Buckling ◽  
Uniform Load ◽  
Calculated Length ◽  
Arching Effect ◽  
Arch Effect ◽  
Rigid Frame ◽  
Standards And Regulations ◽  
Inclined Beam

Aiming at the limitation of the calculated length coefficient of the gable portal rigid frame columns in the standards and regulations, which ignores the influence of the arch effect caused by the axial force of the inclined beams lope, this paper uses the elastic buckling equation of the solid-webbed articulated pitched-roof frame, considered 𝑃−𝛥 second-order effect and the arch effect of the inclined beam under uniform load together. And the length coefficient calculated is analyzed. It is concluded that the larger the slope of the inclined beam and the ratio of the rigid frame span are, the more obvious the arching effect is, and the larger the calculated length coefficient of the rigid frame column is.

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

Influence of cropping on effective-length factors of tubular steel struts

1979 ◽  
Vol 6 (2) ◽  
pp. 260-267 ◽  
Author(s):  
G. Morris
Keyword(s):  
Experimental Investigation ◽  
Effective Length ◽  
Elastic Buckling ◽  
Buckling Loads ◽  
Fabrication Procedure

An experimental investigation is made of the influence of cropping, a relatively new fabrication procedure, on effective-length factors for round tubular steel struts. Tests of 18 companion pairs of cropped and sawn strut specimens, with end plates providing various degrees of end-fixity, are described. The Southwell plot method, using both transverse displacements and strains, is used to determine elastic buckling loads. These are in turn used to compute effective-length factors. Those for the sawn specimens approach 1.0 for very small end-fixity and 0.5 for large end-fixity. Except for the specimens with very small end-fixity, the effective-length factors for the cropped specimens are approximately 15% larger than those for the corresponding sawn specimens.

scholarly journals Alternative Design Procedure for RC-Braced Long Columns Based on New Moment Magnifiers Matrix

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Mohamed Farouk ◽  
Majed Alzara ◽  
A. Ehab ◽  
A. M. Yosri
Keyword(s):  
Flexural Rigidity ◽  
Design Procedure ◽  
Bending Moment ◽  
Order Effect ◽  
Second Order ◽  
Effective Length ◽  
Column Height ◽  
Order Effects ◽  
Order Analysis ◽  
Proposed Model

Based on modified methods for the results of first-order analysis of RC columns, different codes approximate the second-order effects by using equations focusing on the maximum additional moment through the column height. These equations did not refer to the additional moments between the column and the connected beam, only the effect of the connected beams is taken into consideration by dealing with the effective length of the column, not the total length. Moreover, these equations did not take into account the second-order effect, which is caused by axial force and the inverse moments due to beam restriction for the column ends. This paper presents a new moment magnifiers matrix for the additional moments at the connection between braced columns and the connected beams as a simplified computation that can be used in the design procedure. That is through an equation based on transforming the original long column in second-order analysis to an equivalent isolated column. The equivalent column was represented as an element restricted with rotational spring support at its ends, and it is subjected to lateral distributed loads that have the same influence of the second-order effect on the induced additional moments in the long column. The suggested equivalent column can be used to form the additional bending moment diagram, also to compute the additional deformations as well. Numerous factors were analyzed linearly by using the presented new moment magnifiers matrix and finite element method, and the results proved the efficiency of the proposed model. Although the presented suggested model is based on the isolated analysis of the long column, the effect of the additional moments in the adjacent long column can be considered by presented two suggestions to improve the model. Also, development was proceeded on the model by modifying the flexural rigidity (EI) which is recommended in ACI to appropriate the time of failure. The additional moment values of the developed model were close to the values calculated by the ACI equation.

NON-LINEAR ANALYSIS OF THREE-PINNED CIRCULAR ARCHES

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Yong-Lin Pi ◽  
Mark Andrew Bradford ◽  
Kai Luo ◽  
Wei Gao
Keyword(s):  
Compressive Force ◽  
Bending Moment ◽  
Elastic Buckling ◽  
Radial Load ◽  
Bending Moments ◽  
Uniform Load ◽  
Axial Compressive Force ◽  
Plane Analysis ◽  
Linear Behavior ◽  
Non Linear

Because a three-pinned circular arch is statically determinate, when it is subjected to a uniform radial load q, linear in-plane analysis has shown that the uniform load will produce quite simple internal actions: a uniform axial compressive force N = qR and zero-bending moment, where R is the radius of the arch. This is consistent with equations in textbooks for structural mechanics. However, the non-linear behavior and buckling of three-pinned arches are very different from their linear counterparts. The uniform radial load can produce significant bending moments in the three-pinned arches, and the value of the uniform axial compressive force in the three-pinned arches is greater than qR. In addition, it is also shown in this paper that the solutions for the in-plane elastic buckling load of three-pinned arches available in the open literature cannot predict their in-plane buckling loads correctly.

Second Order Analysis on a Typical Steel Industrial Plant

2011 ◽  
Vol 243-249 ◽  
pp. 1405-1408
Author(s):  
Bo Li ◽  
Shao Bin Hu ◽  
Ya Xin Sun ◽  
Yan Wang
Keyword(s):  
Finite Element ◽  
Order Effect ◽  
Second Order ◽  
Nonlinear Finite Element ◽  
Effective Length ◽  
Industrial Plant ◽  
Order Analysis ◽  
First Order ◽  
Engineering Steel ◽  
Analysis Design

The deficiency of effective length approach and the necessity of second order analysis design on nonferrous engineering steel industrial plant are emphasized. Second order analysis approach by nonlinear finite-element with ANSYS is used to design an industrial plant. The example indicates that second-order effect should not be neglect and the result of first order analysis is not safe enough for industrial plant.

scholarly journals STUDI PERBANDINGAN STRESS RATIO PADA PORTAL BAJA MENGGUNAKAN BRACING DENGAN EFFECTIVE LENGTH METHOD (ELM) DAN DIRECT ANALISYS METHOD (DAM)

2019 ◽  
Vol 2 (2) ◽  
pp. 141-148
Author(s):  
Cut M. Rani ◽  
Muttaqin Muttaqin ◽  
Teuku Budi Aulia
Keyword(s):  
Stress Ratio ◽  
Steel Structure ◽  
Direct Analysis ◽  
Order Effect ◽  
Frame Structure ◽  
Effective Length ◽  
Structure Stability ◽  
The Difference ◽  
Effective Length Method ◽  
Steel Frame Structure

In the design of high and low-rise buildings, structural systems should consider the requirements of strength, stifness, and stability. The addition of bracing affects the stiffness of the structure of the building. In SNI 03-1729-2002 there is an Effective Length Method (ELM) method which only recommends first-order analysis with amplification factor. However, currently there is a new structural design regulation that is SNI 1729: 2015 which refers to the American Institute of Steel Contruction (AISC 2010) where the steel structure stability planning has taken into account the second-order effect directly. This study aims to compare the application of Direct Analysis Method (DAM) and Effective Length Method (ELM) on 2D simple structure, where the comparison of both methods is focused on stress ratio value, which aims to determine more effective and efficient method in designing of braced steel frame structure. The difference values of stress ratio obtained in this study varies from 0.1 to 8.9%, where the value of DAM stress ratio is smaller than ELM. Comparison between the two methods shows that DAM is a more effective method and results in higher profile capacity than ELM.

Buckling Load of Elliptic Paraboloidal Single Layer Reticulated Roofs under Uniform Load

2005 ◽  
Vol 20 (2) ◽  
pp. 91-106 ◽  
Author(s):  
Shiro Kato ◽  
Yoshiro Yamauchi ◽  
Takashi Ueki
Keyword(s):  
Approximate Formula ◽  
Slenderness Ratio ◽  
Single Layer ◽  
Elastic Buckling ◽  
Uniform Load ◽  
Column Buckling ◽  
Buckling Loads ◽  
Buckling Strength ◽  
Practical Design ◽  
Linear Buckling

The present paper discusses buckling strength of elliptic paraboloidal reticular roofs under a uniform load on a rectangular plan. The roofs are assumed as three way single layers with a pin-support at all peripheries on a rectangular plan. The buckling analyses are performed for linear buckling, elastic buckling and elastic-plastic buckling. The results of buckling loads are formulated based on two procedures for practical design use. One is an explicit but approximate formula for elastic buckling loads using a knock down factor and the other one is an implicit expression for buckling loads interpreted into a column buckling strength in terms of generalized slenderness ratio.

Constitutive Models for Uniaxially-Post-Buckled Square Lattices

2014 ◽  
Vol 1016 ◽  
pp. 105-110
Author(s):  
Edgar A. Flores Parra ◽  
Alessandro Spadoni
Keyword(s):  
Constitutive Models ◽  
Structural Features ◽  
Square Lattice ◽  
Elastic Buckling ◽  
Strain Response ◽  
Uniform Load ◽  
Stress Strain ◽  
Unit Cells ◽  
Slender Beams ◽  
2D Fft

The objective of this paper is to analyse the mechanical stress-strain response of an ini-tially uniaxially-post-buckled periodic structure. This requires selecting a representative volume ele-ment (RVE) that contains all the micro-structural features and responds as the infinite medium when subjected to uniform load and boundary conditions. Selection is done by analysing the stress-strain response for macro-cells of increasing size as well as identifying dominant length scales with a 2D-FFT. For a uniaxially–post buckled square lattice, the RVE is found to be a Y3x3 (3x3 unit cells for the undeformed configuration). A study for the post-buckled behaviour of the pre-stressed RVE, with in-ternal components modelled as long slender beams, beyond elastic buckling is presented. Incremental constitutive models are then formulated analytically and numerically for loads above the critical load.

Buckling Load of Elliptic Paraboloidal Single Layer Reticulated Roofs with Simple Supports under Uniform Load

2005 ◽  
Vol 20 (4) ◽  
pp. 211-224 ◽  
Author(s):  
Shiro Kato ◽  
Yoshiro Yamauchi ◽  
Takashi Ueki ◽  
Kazune Okuhira
Keyword(s):  
Slenderness Ratio ◽  
Single Layer ◽  
Elastic Buckling ◽  
Uniform Load ◽  
Column Buckling ◽  
Buckling Loads ◽  
Buckling Strength ◽  
Linear Buckling ◽  
Simple Support ◽  
Simple Supports

The present paper discusses buckling strength of elliptic paraboloidal reticular roofs under uniform load with a rectangular plan. The roofs are assumed as three way single layers with a simple support at all peripheries of a rectangular plan. The buckling analyses are performed for linear buckling, elastic buckling, and elastic-plastic buckling. The results of buckling loads are formulated based on two procedures for practical design use. One is an explicit formula for elastic buckling loads using a knock down factor and the other one is an implicit expression for buckling loads interpreted as a column buckling strength in terms of generalized slenderness ratio.

Tracing Activations of Diagnostic Hypotheses Reveals Memory Dynamics of a Primacy Order Effect

2013 ◽  
Author(s):  
Felix G. Rebitschek ◽  
◽  
Josef F. Krems ◽  
Georg Jahn
Keyword(s):  
Order Effect
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