scholarly journals Experimental and Numerical Studies on the Shear Stability of Ship’s Thin Plates

2021 ◽  
Vol 28 (4) ◽  
pp. 133-141
Author(s):  
Xiaowen Li ◽  
Zhaoiy Zhu ◽  
Qinglin Chen ◽  
Yingqiang Cai ◽  
Miaojiao Peng
Keyword(s):  
Numerical Simulation ◽  
Thin Plate ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Thin Plates ◽  
Displacement Curve ◽  
Plane Shear ◽  
Critical Buckling Load ◽  
Full Field ◽  
Shear Stability

Abstract The stability of thin plate plays an important role in the design and strength check of ship structure. In order to study the shear stability of ship’s thin plates, in-plane shear buckling tests were carried out using a picture frame fixture and a 3D full-field strain measurement system. The critical buckling load, full-field displacement/strain information, and load-displacement curve were obtained. The finite element model with the frame fixture was established based on ABAQUS, with the eigenvalue buckling analysis and nonlinear buckling analysis being carried out to obtain the mechanical response information of the buckling and post-buckling of the ship’s thin plate. The effectiveness and accuracy of the numerical simulation method are verified by comparing the numerical simulation with the experimental results. On this basis, the critical buckling load obtained by shear test, numerical simulation, and theoretical calculation is analyzed, and the function of the frame shear fixture and its influence on the critical buckling load are defined. The research in this paper provides a useful reference for the testing and simulation of in-plane shear stability of ship’s thin plates.

Thermal buckling analysis of double-walled carbon nanotubes considering the small-scale length effect

2011 ◽  
Vol 225 (1) ◽  
pp. 248-256 ◽  
Author(s):  
A Ghorbanpour Arani ◽  
M Mohammadimehr ◽  
A R Saidi ◽  
S Shogaei ◽  
A Arefmanesh
Keyword(s):  
Temperature Change ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Small Scale ◽  
Buckling Mode ◽  
Critical Buckling Load ◽  
Winkler Model ◽  
Non Local ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this article, the buckling analysis of a double-walled carbon nanotube (DWCNT) subjected to a uniform internal pressure in a thermal field is investigated. The effects of the temperature change, the surrounding elastic medium based on the Winkler model, and the van der Waals forces between the inner and the outer tubes are considered using the continuum cylindrical shell model. The small-length scale effect is also included in the present formulation. The results show that there is a unique buckling mode corresponding to each critical buckling load. Moreover, it is shown that the non-local critical buckling load is lower than the local critical buckling load. It is concluded that, at low temperatures, the critical buckling load for the infinitesimal buckling of a DWCNT increases as the magnitude of temperature change increases whereas at high temperatures, the critical buckling load decreases with the increasing of the temperature.

Buckling analysis of functionally graded annular sector plates resting on elastic foundations

2010 ◽  
Vol 225 (2) ◽  
pp. 312-325 ◽  
Author(s):  
A Naderi ◽  
A R Saidi
Keyword(s):  
Boundary Conditions ◽  
Elastic Foundation ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Elastic Foundations ◽  
Annular Sector ◽  
Sector Plate ◽  
Annular Sector Plate

In this study, an analytical solution for the buckling of a functionally graded annular sector plate resting on an elastic foundation is presented. The buckling analysis of the functionally graded annular sector plate is investigated for two typical, Winkler and Pasternak, elastic foundations. The equilibrium and stability equations are derived according to the Kirchhoff's plate theory using the energy method. In order to decouple the highly coupled stability equations, two new functions are introduced. The decoupled equations are solved analytically for a plate having simply supported boundary conditions on two radial edges. Satisfying the boundary conditions on the circular edges of the plate yields an eigenvalue problem for finding the critical buckling load. Extensive results pertaining to critical buckling load are presented and the effects of boundary conditions, volume fraction, annularity, plate thickness, and elastic foundation are studied.

Buckling Analysis of Circular FGM Plate Having Variable Thickness Under Uniform Compression by Finite Element Method

2005 ◽  
Author(s):  
Abazar Shamekhi ◽  
Mohammad H. Naei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Variable Thickness ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Buckling Load ◽  
Thin Plates ◽  
Thickness Variation ◽  
Simply Supported ◽  
Element Method

This study presents the buckling analysis of radially-loaded circular plate with variable thickness made of functionally-graded material. The boundary conditions of the plate is either simply supported or clamped. The stability equations were obtained using energy method based on Love-Kichhoff hypothesis and Sander’s non-linear strain-displacement relation for thin plates. The finite element method is used to determine the critical buckling load. The results obtained show good agreement with known analytical and numerical data. The effects of thickness variation and Poisson’s ratio are investigated by calculating the buckling load. These effects are found not to be the same for simply supported and clamped plates.

Buckling Analysis of Shells with a Circumferential Crack

2006 ◽  
Vol 306-308 ◽  
pp. 55-60
Author(s):  
I.S. Putra ◽  
T. Dirgantara ◽  
Firmansyah ◽  
M. Mora
Keyword(s):  
Boundary Conditions ◽  
Cylindrical Shells ◽  
Buckling Analysis ◽  
Numerical Results ◽  
Buckling Load ◽  
Numerical Analyses ◽  
Radius Of Curvature ◽  
Critical Buckling Load ◽  
Different Boundary Conditions ◽  
Circumferential Crack

In this paper, buckling analysis of cylindrical shells with a circumferential crack is presented. The analyses were performed both numerically using FEM and experimentally. The numerical analyses and experiments were conducted for several crack lengths and radius of curvature, and two different boundary conditions were applied, i.e. simply support and clamp in all sides. The results show the effect of the presence of crack to the critical buckling load of the shells. There are good agreements between experimental and numerical results.

scholarly journals Mechanical Buckling Analysis of Saturated Porous Functionally Graded Elliptical Plates Subjected to In-Plane Force Resting on Two Parameters Elastic Foundation Based on HSDT

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Mohammad Hossein Sharifan ◽  
Mohsen Jabbari
Keyword(s):  
Elastic Foundation ◽  
Ritz Method ◽  
Shear Deformation Theory ◽  
Potential Energy Function ◽  
Buckling Analysis ◽  
Functionally Graded ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Mechanical Buckling ◽  
Two Parameters

Abstract In this paper, mechanical buckling analysis of a functionally graded (FG) elliptical plate, which is made up of saturated porous materials and is resting on two parameters elastic foundation, is investigated. The plate is subjected to in-plane force and mechanical properties of the plate assumed to be varied through the thickness of it according to three different functions, which are called porosity distributions. Since it is assumed that the plate to be thick, the higher order shear deformation theory (HSDT) is employed to analyze the plate. Using the total potential energy function and using the Ritz method, the critical buckling load of the plate is obtained and the results are verified with the simpler states in the literature. The effect of different parameters, such as different models of porosity distribution, porosity variations, pores compressibility variations, boundary conditions, and aspect ratio of the plate, is considered and has been discussed in details. It is seen that increasing the porosity coefficient decreases the stiffness of the plate and consequently the critical buckling load will be reduced. Also, by increasing the pores' compressibility, the critical buckling load will be increased. Adding the elastic foundation to the structure will increase the critical buckling load. The results of this study can be used to design more efficient structures in the future.

Mechanical buckling of nanocomposites: Experimental and numerical investigations

2020 ◽  
pp. 096739112096844
Author(s):  
John Raphael ◽  
Arunkumar G Bhat ◽  
Jackson Siby ◽  
Blestin Dino Geevarghese ◽  
Nivish George ◽  
...  
Keyword(s):  
Flexural Modulus ◽  
Buckling Load ◽  
Experimental Results ◽  
Displacement Curve ◽  
Nonlinear Finite Element Method ◽  
Deflection Curve ◽  
Close Match ◽  
Critical Buckling Load ◽  
Buckling Behavior ◽  
Mechanical Buckling

The proposed research explores Multi-Walled Carbon Nanotube’s (MWCNT’s) effect on the mechanical buckling behavior of glass fiber-enhanced thermosetting composites using UTM and the load vs displacement curve is plotted. Using the inflection point method, the critical buckling load is obtained from the load vs displacement curve for beams with three different volume fractions of MWCNT. The nonlinear finite element method is used to numerically obtain the load vs deflection curve and the numerical results are compared with the experimental results, and a close match is found with the experimental results. It is observed that the nonlinearity associated with the structure can significantly reduce the critical buckling load. The critical buckling load is found to increase and reported a 27.4% increase in buckling load with 0.3 wt.% of MWCNT which could be accounted for the increase in flexural modulus of the material.

Global Buckling Analysis of Stem Pipe During Side-Step in J-Lay Tower

2015 ◽  
Author(s):  
Bob (H. E. J.) van der Heijden ◽  
Richard Liu ◽  
Gabriel Vazquez Perez ◽  
Henk Smienk
Keyword(s):  
Bending Moment ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Free Standing ◽  
Critical Buckling Load ◽  
Environmental Loads ◽  
Analysis Methodology ◽  
Buckling Behavior ◽  
Step Procedure ◽  
Global Buckling

Within Heerema Marine Contractors’ (HMC) global installation analysis scope, the sidestep procedure of structures (e.g. in-line tee structure, 2nd end FLET structure or upper riser assembly structure) is identified that might require global buckling analysis. During a side-step procedure a structure is skidded out of the J-Lay tower while free-standing via the stem pipe on the hang off collar of the last hex-joint. While skidding the tower cannot support the structure vertically, only horizontally via a side step clamp higher up in the tower. Hence the stem pipe could buckle globally under the structure weight. The weight of the structure causes compression in the stem pipe and a center of gravity offset of the structure with respect to the pipe centerline causes a bending moment leading to potential global buckling. A global buckling analysis must be performed to check this load case. The purpose of this paper is to provide validation for the use of Flexcom for performing global buckling analysis for the side-step procedure of structures in the J-Lay tower. In order to prove that Flexcom can indeed model global buckling behavior with sufficient accuracy, the critical buckling load obtained is validated using the FE packages Abaqus and Ansys. This comparison serves as validation, not only for the use of Flexcom, but also for the method used to determine the critical buckling load in Flexcom. The analysis methodology used to assess a pipeline or riser for global buckling behavior is updated using the benefits of Flexcom. The use of Flexcom for global buckling analysis is more efficient, due to the ease and simplicity of modeling, and allows dynamic load cases, due to environmental loads and vessel motions, to be analyzed. Hence the potential benefit of performing global buckling analysis in Flexcom.

Numerical Investigation on the Buckling Failure of Slender Tubular Member with Cutout Presence

2018 ◽  
Vol 881 ◽  
pp. 122-131 ◽  
Author(s):  
Miftahul Iman ◽  
Bambang Suhendro ◽  
Henricus Priyosulistyo ◽  
Muslikh
Keyword(s):  
Nonlinear Analysis ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Equilibrium Equations ◽  
Buckling Mode ◽  
Euler Formula ◽  
Critical Buckling Load ◽  
Shell Elements ◽  
Nonlinear Equilibrium ◽  
Buckling Failure

Pitting corrosion often leads to the creation of small holes in steel tubular member of platform structures when a protective coating is damaged. A single pit on slender compression element can cause a significant reduction in the buckling capacity of the member. Euler formula is no longer applicable for determining the critical buckling load when cutout presence on the member. This research was conducted to numerically study the effect of a circular hole on the buckling capacity of slender steel tubular member. A variation on hole positions was at 0.125 L, 0.25 L, 0.375 L, and 0.5 L, where L is the length of the member. The hole was taken to be 0.5 pipe diameter. Two nonlinear geometric 3D Finite Element models were developed to analyzed the member critical buckling load: (a) buckling analysis, where the problem was formulated as eigenvalue problem based on the nonlinear incremental equilibrium equations, and (b) nonlinear analysis, where the nonlinear equilibrium equations were developed and solved by several schemes to get the load – deflection curve. For the both models, the tubular member was discretized into: (a) shell elements, and (b) solid elements. The numerical results were verified by experimental investigation. The results showed that: (a) the presence of cutout reduced the buckling load significantly, (b) the reduction ranging from 3% to 10% depending on the hole positions, (c) the maximum reduction occurs when the hole position was in the middle of the member length, (d) compared to experimental results, the critical buckling load obtained from buckling analysis deviated 1~4% while those of nonlinear analysis deviated 1~5%, (e) the buckling mode corresponded with member bent away to opposite side of the cutout position.

Virtual Vibration Correlation Technique (VCT) for Nonlinear Analysis of Metallic and Composite Structures

2018 ◽  
Author(s):  
Alfonso Pagani ◽  
Riccardo Augello ◽  
Erasmo Carrera
Keyword(s):  
Composite Structures ◽  
Sudden Change ◽  
Path Following ◽  
Finite Element Approximation ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Correlation Technique ◽  
Element Approximation ◽  
Critical Buckling Load ◽  
Generalized Variables

An important role in the design of structure is represented by the buckling analysis. The loading and service conditions, in which structures usually work, may significantly afflict their equilibrium state. This aspect often forces the design engineers to perform an accurate buckling analysis, in order to calculate critical loads of the structure. In fact, this critical load causes a sudden change of the structure, leading to a radical decrease in the loadcarrying capability. For these reasons, buckling analysis of beam-columns has been widely investigated in the past and recent years. One of the most important experimental technology to calculate the critical buckling load of structures if represented by the Vibration Correlation Technique (VCT). It allows determining equivalent boundary conditions and buckling load for several types of structures and its strength is represented by the fact that it is a non-destructive methodology: essentially, the stability loads were determined by interpolating, until singularity, the natural frequency of the structure subjected to progressive higher loadings, without reaching the instability point. VCT is already widely used for beam, plate and shell structures. This paper intends to assess a numerical simulation of the experimental data needed for the Vibration Correlation Technique. The solution proposed is developed in the domain of the Carrera Unified Formulation (CUF), according to which theories of structures can degenerate into a generalized kinematics that makes use of an arbitrary expansion of the generalized variables. Moreover, in order to reproduce results obtained in an experimental way, when large displacement and rotations may occur, geometrical nonlineatities have been taken into account. Thus, a finite element approximation is used along with a path-following method to perform nonlinear analyses. Different types of structures have been analyzed, made with metallic and composite materials, and some results are compared with others found in the VCT literature. Results show how this methodology can well evaluate the natural frequencies on the structure in a geometrical nonlinear framework, and so also the critical buckling load.

scholarly journals Numerical buckling analysis of cracked Bi-material thin plates

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094464
Author(s):  
Sara Ould Hamouda ◽  
Nabil Kazi Tani ◽  
Tawfik Tamine
Keyword(s):  
Numerical Simulations ◽  
Thin Plate ◽  
Interface Crack ◽  
Research Work ◽  
Interfacial Crack ◽  
Tensile Loading ◽  
Buckling Analysis ◽  
The Other ◽  
Thin Plates ◽  
Buckling Behavior

The aim of this present study is to analyze numerically the buckling behavior of cracked thin bi-material structures subjected to compression and tensile stresses and this, by considering the evolution of crack lengths and its orientations at the interface. This research work allows to quantify numerically the buckling phenomenon which can affects the thin plates for both cases, with and without interface crack especially, when the plate is subjected to tensile loading. The main important results of numerical simulations show that for the case of compression loading, the presence of interfacial crack increases significantly the strength of the thin plate against buckling phenomena. In the other hand, thin crack plates buckling is more pronounced when the crack tip is close to the interface (θ = 90°, θ = 75°). Finally, unlike to the case of homogeneous thin plates, the incorporation of bi-material aspect in thin plates design offers more strength against buckling either for compression or tensile loading.

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