scholarly journals Catastrophic Influence of Global Distortional Modes on the Post-Buckling Behavior of Opened Columns

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3314
Author(s):  
Andrzej Teter ◽  
Zbigniew Kolakowski
Keyword(s):  
Cross Sections ◽  
Carrying Capacity ◽  
Strong Interactions ◽  
Load Carrying Capacity ◽  
Buckling Modes ◽  
Flexural Buckling ◽  
Load Carrying ◽  
Post Buckling ◽  
Global Modes ◽  
Thin Walled

The multimodal buckling of thin-walled isotropic columns with open cross-sections under uniform compression is discussed. Column lengths were selected to enable strong interactions between selected eigenmodes. In the case of short columns or very long ones subjected to compression, single-mode buckling can be observed only and the effect under discussion does not occur. In the present study, the influence of higher global modes on the load-carrying capacity and behavior in the post-buckling state of thin-walled structures with open cross-sections is analyzed in detail. In the literature known to the authors, higher global modes are always neglected practically in the analysis due to their very high values of bifurcation loads. However, the phenomenon of an unexpected loss in the load-carrying capacity of opened columns can be observed in the experimental investigations. It might be explained using multimode buckling when the higher global distortional-flexural buckling modes are taken into account. In the conducted numerical simulations, a significant influence of higher global distortional-flexural buckling modes on the post-buckling equilibrium path of uniformly compressed columns with C- and TH-shaped (the so-called “top-hat”) cross-sections was observed. The columns of two lengths, for which strong interactions between selected eigenmodes were seen, were subject to consideration. Two numerical methods were applied, namely, the semi-analytical method (SAM) using Koiter’s perturbation approach and the finite element method (FEM), to solve the problem. The SAM results showed that the third mode had a considerable impact on the load-carrying capacity, whereas the FEM results confirmed a catastrophic effect of the modes on the behavior of the structures under analysis, which led to a lack of convergence of numerical calculations despite an application of the Riks algorithm. All elastic-plastic effects were neglected.

scholarly journals Eigenproblem Versus the Load-Carrying Capacity of Hybrid Thin-Walled Columns with Open Cross-Sections in the Elastic Range

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3468
Author(s):  
Zbigniew Kolakowski ◽  
Andrzej Teter
Keyword(s):  
Cross Sections ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Equilibrium Path ◽  
Load Carrying Capacity ◽  
Nonlinear Buckling ◽  
Elastic Range ◽  
Load Carrying ◽  
Thin Walled ◽  
Ultimate Load Carrying Capacity

The phenomena that occur during compression of hybrid thin-walled columns with open cross-sections in the elastic range are discussed. Nonlinear buckling problems were solved within Koiter’s approximation theory. A multimodal approach was assumed to investigate an effect of symmetrical and anti-symmetrical buckling modes on the ultimate load-carrying capacity. Detailed simulations were carried out for freely supported columns with a C-section and a top-hat type section of medium lengths. The columns under analysis were made of two layers of isotropic materials characterized by various mechanical properties. The results attained were verified with the finite element method (FEM). The boundary conditions applied in the FEM allowed us to confirm the eigensolutions obtained within Koiter’s theory with very high accuracy. Nonlinear solutions comply within these two approaches for low and medium overloads. To trace the correctness of the solutions, the Riks algorithm, which allows for investigating unsteady paths, was used in the FEM. The results for the ultimate load-carrying capacity obtained within the FEM are higher than those attained with Koiter’s approximation method, but the leap takes place on the identical equilibrium path as the one determined from Koiter’s theory.

Post-buckling Behavior of Stiffened Cross-Ply Cylindrical Shells

1994 ◽  
Vol 61 (4) ◽  
pp. 998-1000 ◽  
Author(s):  
M. Savoia ◽  
J. N. Reddy
Keyword(s):  
Axial Compression ◽  
Carrying Capacity ◽  
Shell Theory ◽  
Load Carrying Capacity ◽  
Imperfection Sensitivity ◽  
Buckling Modes ◽  
Geometric Imperfection ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Post Buckling

The post-buckling of stiffened, cross-ply laminated, circular determine the effects of shell lamination scheme and stiffeners on the reduced load-carrying capacity. The effect of geometric imperfection is also included. The analysis is based on the layerwise shell theory of Reddy, and the “smeared stiffener” technique is used to account for the stiffener stiffness. Nu cylinders under uniform axial compression is investigated to merical results for stiffened and unstiffened cylinders are presented, showing that imperfection-sensitivity is strictly related to the number of nearly simultaneous buckling modes.

scholarly journals Theoretical and Experimental Stress-Strain Analysis of Compressed Steel Members with Closed Cross-Sections

2013 ◽  
Vol 8 (1) ◽  
pp. 59-66
Author(s):  
Michal Tomko ◽  
Mohamad Al Ali ◽  
Ivo Demjan
Keyword(s):  
Cross Sections ◽  
Carrying Capacity ◽  
Strain Analysis ◽  
Load Carrying Capacity ◽  
Steel Members ◽  
Fundamental Information ◽  
Load Carrying ◽  
Numerical Research ◽  
Thin Walled ◽  
Theoretical Results

Abstract The paper presents fundamental information about experimental and theoretic-numerical research to determinate the load-carrying capacity of thin-walled cold-formed compressed steel members. The investigated members have closed cross-sections made from homogeneous materials. The theoretic-numerical analysis in this paper is oriented on the modeling of the initial deviations effects, caused by production process, on the load-carrying capacities of mentioned members, while the experimental investigation is to verify the theoretical results and to investigate the behavior of mentioned members during the loading process.

Analysis of Seismic Performance of RC Frames with Centrally Reinforced Columns

2013 ◽  
Vol 671-674 ◽  
pp. 1319-1323
Author(s):  
Zi Xue Lei ◽  
Yu Hang Han ◽  
San Sheng Dong ◽  
Jun Qing Guo
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Pushover Analysis ◽  
Seismic Load ◽  
Load Carrying Capacity ◽  
Rc Columns ◽  
Rc Column ◽  
Rc Frames ◽  
Load Carrying

A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.

Load-carrying capacity of thin-walled composite beams subjected to pure bending

2017 ◽  
Vol 115 ◽  
pp. 76-85 ◽  
Author(s):  
Adrian Gliszczyński ◽  
Tomasz Kubiak
Keyword(s):  
Carrying Capacity ◽  
Composite Beams ◽  
Load Carrying Capacity ◽  
Pure Bending ◽  
Load Carrying ◽  
Thin Walled

scholarly journals Load carrying capacity of the eccentric joint in the truss made of open cross-sections

2018 ◽  
Vol 219 ◽  
pp. 02002
Author(s):  
Małgorzata Gordziej-Zagórowska ◽  
Elżbieta Urbańska-Galewska
Keyword(s):  
Numerical Analysis ◽  
Cross Section ◽  
Experimental Research ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Main Achievement ◽  
Joint Area ◽  
Load Carrying ◽  
Open Cross Section

The influence of eccentricity at intersections of truss members on the load carrying capacity of the truss joint is presented in the paper. The research truss elements were designed as cold-formed open cross section. Analytical calculations, numerical analysis and experimental research were conducted to reveal how the eccentricity affects the effort of material in the joint area. The results of analysis and investigations are compared and discussed. The main achievement of the tests carried out is statement that slender plane members of the compression chords are safe compared with the results of analytical calculations.

scholarly journals The Influence of the Internal Forces of the Buckling Modes on the Load-Carrying Capacity of Composite Medium-Length Beams under Bending

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 455 ◽  
Author(s):  
Monika Zaczynska ◽  
Zbigniew Kolakowski
Keyword(s):  
Carrying Capacity ◽  
Internal Force ◽  
Load Carrying Capacity ◽  
Buckling Modes ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Load Carrying ◽  
Internal Forces ◽  
The Individual ◽  
Interactive Buckling

The distribution of the internal forces corresponding to the individual buckling modes of lip-channel (LC) beams is investigated using the Semi Analytical Method (SAM) and the Finite Element Method (FEM). Channel section beams made of 8-layered GFRP (Glass Fiber Reinforced Polymer) laminate with three different layer arrangements were considered. The effect of the internal forces on the non-linear first-order coefficients corresponding to the interactive buckling was also studied. Moreover, distributions of the internal forces corresponded to the loading, leading to structure failure for which the load-carrying capacity was determined. The results indicated a high influence of the Nx internal force component on the buckling loads and load-carrying capacity of the LC-beams.

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