A new approach to the buckling resistance assessment of pressurized spherical shells

2013 ◽  
pp. 179-182 ◽  
Author(s):  
P Błażejewski ◽  
J Marcinowski
Keyword(s):  
Spherical Shells ◽  
New Approach ◽  
Buckling Resistance ◽  
Resistance Assessment

Buckling Design of Imperfect Welded Hemispherical Shells Subjected to External Pressure

1991 ◽  
Vol 205 (3) ◽  
pp. 175-188 ◽  
Author(s):  
G D Galletly ◽  
J Blachut
Keyword(s):  
Experimental Information ◽  
External Pressure ◽  
Design Stage ◽  
Arc Length ◽  
Spherical Shells ◽  
Geometric Imperfections ◽  
Collapse Pressure ◽  
Buckling Resistance ◽  
Initial Geometric Imperfections ◽  
Hemispherical Shells

Welded hemispherical or spherical shells in practice have initial geometric imperfections in them that are random in nature. These imperfections determine the buckling resistance of a shell to external pressure but their magnitudes will not be known until after the shell has been built. If suitable simplified, but realistic, imperfection shapes can be found, then a reasonably accurate theoretical prediction of a spherical shell's buckling/collapse pressure should be possible at the design stage. The main aim of the present paper is to show that the test results obtained at the David Taylor Model Basin (DTMB) on 28 welded hemispherical shells (having diameters of 0.75 and 1.68 m) can be predicted quite well using such simplified shape imperfections. This was done in two ways. In the first, equations for determining the theoretical collapse pressures of externally pressurized imperfect spherical shells were utilized. The only imperfection parameter used in these equations is δ0, the amplitude of the inward radial deviation of the pole of the shell. Two values for δ0 were studied but the best overall agreement between test and theory was found using δ0 = 0.05 ✓ (Rt). This produced ratios of experimental to numerical collapse pressures in the range 0.98–1.30 (in most cases the test result was the higher). The second approach also used simplified imperfection shapes, but in conjunction with the shell buckling program BOSOR 5. The arc length of the imperfection was taken as simp = k ✓ (Rt) (with k = 3.0 or 3.5) and its amplitude as δ0 = 0.05√(Rt). Using this procedure on the 28 DTMB shells gave satisfactory agreement between the experimental and the computer predictions (in the range 0.92–1.20). These results are very encouraging. The foregoing method is, however, only a first step in the computerized buckling design of welded spherical shells and it needs to be checked against spherical shells having other values of R/t. In addition, more experimental information on the initial geometric imperfections in welded spherical shells (and how they vary with R/t) is desirable. A comparison is also given in the paper of the collapse pressures of spherical shells, as obtained from codes, with those predicted by computer analyses when the maximum shape deviations allowed by the codes are employed in the computer programs. The computed collapse pressures are frequently higher than the values given by the buckling strength curves in the codes. On the other hand, some amplitudes of imperfections studied in the paper give acceptable results. It would be helpful to designers if agreement could be reached on an imperfection shape (amplitude and arc length) that was generally acceptable. Residual stresses are not considered in this paper. They might be expected to decrease a spherical shell's buckling resistance to external pressure. However, experimentally, this does not always happen.

The fuzzy c spherical shells algorithm: A new approach

1992 ◽  
Vol 3 (5) ◽  
pp. 663-671 ◽  
Author(s):  
R. Krishnapuram ◽  
O. Nasraoui ◽  
H. Frigui
Keyword(s):  
Spherical Shells ◽  
New Approach

scholarly journals Buckling of Spherical Concrete Shells

2021 ◽  
Author(s):  
Emad Zolqadr
Keyword(s):  
American Concrete Institute ◽  
Major Effect ◽  
Elastic Behavior ◽  
Fe Method ◽  
Spherical Shells ◽  
Load Combination ◽  
Buckling Behavior ◽  
Buckling Resistance ◽  
Support Conditions ◽  
Concrete Shells

This study is focused on the buckling behavior of spherical concrete shells (domes) under different loading conditions. The background of analytical analysis and recommended equations for calculation of design buckling pressure for spherical shells are discussed in this study. The finite element (FE) method is used to study the linear and nonlinear response of spherical concrete shells under different vertical and horizontal load combination buckling analysis. The effect of different domes support conditions are considered and investigated in this study. Several dome configurations with different geometry specifications are used in this study to attain reliable results. The resulted buckling pressures from linear FE analysis for all the cases are close to the analytical equations for elastic behavior of spherical shells. The results of this study show that geometric nonlinearity widely affects the buckling resistance of the spherical shells. The effect of horizontal loads due to horizontal component of earthquake is not currently considered in the recommended equation by The American Concrete Institute (ACI) to design spherical concrete shells against buckling. However, the results of this study show that horizontal loads have a major effect on buckling pressure and it could not be ignored.

scholarly journals Stability of Thin-Walled Beams with Lateral Continuous Restraint

2015 ◽  
Vol 15 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Ivan Balázs ◽  
Jindřich Melcher
Keyword(s):  
Critical Load ◽  
Cross Sections ◽  
Building Industry ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Load Bearing ◽  
Buckling Resistance ◽  
Resistance Assessment ◽  
Thin Walled

Abstract Metal beams of thin-walled cross-sections have been widely used in building industry as members of load-bearing structures. Their resistance is usually limited by lateral torsional buckling. It can be increased in case a beam is laterally supported by members of cladding or ceiling construction. The paper deals with possibilities of determination of critical load of thin-walled beams with lateral continuous restraint which is crucial for beam buckling resistance assessment

scholarly journals Development of a Procedure for the Determination of the Buckling Resistance of Steel Spherical Shells According to EC 1993-1-6

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 25
Author(s):  
Paweł Błażejewski
Keyword(s):  
Spherical Shell ◽  
Simple Calculation ◽  
Difficult Problem ◽  
Calculation Algorithm ◽  
Spherical Shells ◽  
Engineering Approach ◽  
Low Degree ◽  
Buckling Resistance

This paper presents the process of developing a new procedure for estimating the buckling capacity of spherical shells. This procedure is based entirely on the assumptions included in the standard mentioned, EN-1993-1-6 and also becomes a complement of EDR5th by unifying provisions included in them. This procedure is characterized by clarity and its algorithm is characterized by a low degree of complexity. While developing the procedure, no attempt was made to change the main postulates accompanying the dimensions of the spherical shells. The result is a simple engineering approach to the difficult problem of determining the buckling capacity of a spherical shell. In spite of the simple calculation algorithm for estimating the buckling capacity of spherical shells, the results obtained reflect extremely accurately the behavior of real spherical shells, regardless of their geometry and the material used to manufacture them.

scholarly journals Comparisons of Buckling Capacity Curves of Pressurized Spheres with EDR Provisions and Experimental Results

2017 ◽  
Vol 25 (2) ◽  
pp. 59-76 ◽  
Author(s):  
Paweł Błażejewski ◽  
Jakub Marcinowski
Keyword(s):  
Nonlinear Analysis ◽  
General Procedure ◽  
Experimental Results ◽  
Spherical Shells ◽  
Geometrically Nonlinear Analysis ◽  
Design Recommendations ◽  
Capacity Curves ◽  
Buckling Resistance ◽  
The Stability ◽  
Linear Buckling Analysis

Abstract Existing provisions leading to the assessment of the buckling resistance of pressurised spherical shells were published in the European Design Recommendations (EDR) [1]. This book comprises rules which refer to the stability of steel shells of different shapes. In the first step of the general procedure they require calculation of two reference quantities: the elastic critical buckling reference pRcr and the plastic reference resistance pRpl. These quantities should be determined in the linear buckling analysis (LBA) and in the materially nonlinear analysis (MNA) respectively. Only in the case of spherical shells the existing procedure has exceptional character. It is based on the geometrically nonlinear analysis (GNA) and on the geometrically and materially nonlinear analysis (GMNA), respectively. From this reason, in this particular case there was a need to change the existing approach. The new procedure was presented in the work of Błażejewski & Marcinowski in 2016 (comp. [2]). All steps of the procedure leading to the assessment of buckling resistance of pressurized steel, spherical shells were presented in this work. The elaborated procedure is consistent with provisions of Eurocode EN1993-1-6 (comp. [3]) and with recommendations inserted in Europeans Design Recommendations [1]. The proposed capacity curves were compared with existing proposal published in [1] for three different fabrication quality classes predicted in [3]. In this work also comparisons of author’s proposals with experimental results obtained by other authors were presented.

Buckling resistance assessment of steel I-section beam-columns not susceptible to LT-buckling

2017 ◽  
Vol 17 (2) ◽  
pp. 205-221 ◽  
Author(s):  
Marian Antoni Giżejowski ◽  
Radosław Szczerba ◽  
Marcin Daniel Gajewski ◽  
Zbigniew Stachura
Keyword(s):  
Beam Columns ◽  
Buckling Resistance ◽  
Resistance Assessment

scholarly journals Buckling of Spherical Concrete Shells

2021 ◽  
Author(s):  
Emad Zolqadr
Keyword(s):  
American Concrete Institute ◽  
Major Effect ◽  
Elastic Behavior ◽  
Fe Method ◽  
Spherical Shells ◽  
Load Combination ◽  
Buckling Behavior ◽  
Buckling Resistance ◽  
Support Conditions ◽  
Concrete Shells

This study is focused on the buckling behavior of spherical concrete shells (domes) under different loading conditions. The background of analytical analysis and recommended equations for calculation of design buckling pressure for spherical shells are discussed in this study. The finite element (FE) method is used to study the linear and nonlinear response of spherical concrete shells under different vertical and horizontal load combination buckling analysis. The effect of different domes support conditions are considered and investigated in this study. Several dome configurations with different geometry specifications are used in this study to attain reliable results. The resulted buckling pressures from linear FE analysis for all the cases are close to the analytical equations for elastic behavior of spherical shells. The results of this study show that geometric nonlinearity widely affects the buckling resistance of the spherical shells. The effect of horizontal loads due to horizontal component of earthquake is not currently considered in the recommended equation by The American Concrete Institute (ACI) to design spherical concrete shells against buckling. However, the results of this study show that horizontal loads have a major effect on buckling pressure and it could not be ignored.

Sign in / Sign up

Export Citation Format

Share Document