Buckling Behavior of Horizontal Hydraulic Cylinder Articulated at Both Supports

2020 ◽  
Vol 20 (03) ◽  
pp. 2050033
Author(s):  
Ji Zhou ◽  
Duanwei Shi ◽  
Chengyun Di ◽  
Yang Zhang ◽  
Xionghao Cheng
Keyword(s):  
Numerical Calculation ◽  
Large Deflection ◽  
Beam Theory ◽  
Initial Boundary ◽  
Hydraulic Cylinder ◽  
Buckling Load ◽  
Stability Test ◽  
Practical Calculation ◽  
Critical Buckling Load ◽  
Buckling Behavior

The existing critical buckling load calculation methods of horizontal hydraulic cylinder failed to fully reflect the initial boundary conditions and some critical influence factors, resulting in an unjustified critical buckling load. A new method to analyze the buckling behavior of the horizontal hydraulic cylinder articulated at both supports is developed on basis of large deflection theory and Timoshenko beam theory. Friction at supports, self-weight and initial misalignment by clearances are taken into account. Friction moments of supports are built according to Hertz contact theory. Bending stiffness of cylinder-rod junction is figured out in terms of elastic deformation theory. Runge–Kutta and Newton–Raphson method are used in numerical calculation for the critical buckling load. Practical calculation and stability test are carried out to verify the necessity of considering large deflection and shear effect in the proposed method. Experimental work shows the critical buckling load by the proposed method can well match to that by stability test with 0.55% deviation. Moreover, the numerical calculation results demonstrate that the friction moment of the support at piston rod end is crucial for the buckling behavior. The critical buckling load rises increasingly as the friction coefficient [Formula: see text] rises. As the friction coefficients [Formula: see text] increases from 0 to 0.020, the rise rate of critical buckling load increases from 1.782% to 8.055% per 0.001. And the clearance at cylinder-rod junction is a minor factor on the critical buckling load. As the clearances increase by 10 times, the critical buckling load decreases by 3.542%.

Analytical and numerical calculation of the critical buckling load in compound columns

2020 ◽  
pp. 1-17
Author(s):  
Luay S. Al-Ansari ◽  
Husam Jawad Abdulsamad ◽  
Faeq Hamid Gburi ◽  
Qusay S. Al-Anssari
Keyword(s):  
Numerical Calculation ◽  
Buckling Load ◽  
Critical Buckling Load

scholarly journals Buckling Behavior of Nanobeams Placed in Electromagnetic Field Using Shifted Chebyshev Polynomials-Based Rayleigh-Ritz Method

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1326 ◽  
Author(s):  
Subrat Kumar Jena ◽  
Snehashish Chakraverty ◽  
Francesco Tornabene
Keyword(s):  
Boundary Condition ◽  
Closed Form ◽  
Chebyshev Polynomials ◽  
Ritz Method ◽  
Closed Form Solution ◽  
Form Solution ◽  
Buckling Load ◽  
Mode Shapes ◽  
Critical Buckling Load ◽  
Buckling Behavior

In the present investigation, the buckling behavior of Euler–Bernoulli nanobeam, which is placed in an electro-magnetic field, is investigated in the framework of Eringen’s nonlocal theory. Critical buckling load for all the classical boundary conditions such as “Pined–Pined (P-P), Clamped–Pined (C-P), Clamped–Clamped (C-C), and Clamped-Free (C-F)” are obtained using shifted Chebyshev polynomials-based Rayleigh-Ritz method. The main advantage of the shifted Chebyshev polynomials is that it does not make the system ill-conditioning with the higher number of terms in the approximation due to the orthogonality of the functions. Validation and convergence studies of the model have been carried out for different cases. Also, a closed-form solution has been obtained for the “Pined–Pined (P-P)” boundary condition using Navier’s technique, and the numerical results obtained for the “Pined–Pined (P-P)” boundary condition are validated with a closed-form solution. Further, the effects of various scaling parameters on the critical buckling load have been explored, and new results are presented as Figures and Tables. Finally, buckling mode shapes are also plotted to show the sensitiveness of the critical buckling load.

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.

scholarly journals Buckling and Post-Buckling Behavior of Uniform and Variable-Density Lattice Columns Fabricated Using Additive Manufacturing

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3539 ◽  
Author(s):  
Aamer Nazir ◽  
Ahmad Bin Arshad ◽  
Jeng-Ywan Jeng
Keyword(s):  
Lattice Structure ◽  
Weight Ratio ◽  
High Strength ◽  
Variable Density ◽  
Buckling Load ◽  
Uniform Density ◽  
Lattice Structures ◽  
Critical Buckling Load ◽  
Buckling Behavior ◽  
Post Buckling

Lattice structures are known for their high strength-to-weight ratio, multiple functionalities, lightweight, stiffness, and energy absorption capabilities and potential applications in aerospace, automobile, and biomedical industry. To reveal the buckling (global and local) and post-buckling behavior of different lattice morphologies, both experimental and simulation-based studies were carried out. Additionally, a variable-density lattice structure was designed and analyzed to achieve the optimal value of critical buckling load. Latticed columns were fabricated using polyamide 12 material on multi jet fusion 3D printer. The results exhibited that the buckling in lattice columns depends on the distribution of mass, second moment of inertia I, diameter and position of vertical beams, number of horizontal or inclined beams, and location and angle of the beams that support the vertical beams. The number of horizontal and inclined beams and their thickness has an inverse relation with buckling; however, this trend changes after approaching a critical point. It is revealed that vertical beams are more crucial for buckling case, when compared with horizontal or inclined beams; however, material distribution in inclined or horizontal orientation is also critical because they provide support to vertical beams to behave as a single body to bear the buckling load. The results also revealed that the critical buckling load could be increased by designing variable density cellular columns in which the beams at the outer edges of the column are thicker compared with inner beams. However, post-buckling behavior of variable density structures is brittle and local when compared with uniform density lattice structures.

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.

On the Finite Element Modelling and Simulation of Carbon Nanotubes

2014 ◽  
Vol 607 ◽  
pp. 55-61 ◽  
Author(s):  
Ghasem Ghadyani ◽  
Mojtaba Akbarzade ◽  
Andreas Öchsner
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Beam Theory ◽  
Elastic Stiffness ◽  
Buckling Load ◽  
Timoshenko Beams ◽  
Bernoulli Beam ◽  
Critical Buckling Load ◽  
Beam Elements ◽  
Mesh Density

In this paper, two different beam elements (i.e. according to the Bernoulli beam and Timoshenko beam theory) for the modeling of the behavior of carbon nanotubes are applied. Finite element models are developed for this study with variation of chirality for both zig-zag and armchair configurations of CNTs. The deformations from the finite element simulations are subsequently used to predict the elastic stiffness and the critical buckling load in terms of material and geometric parameters. Furthermore, the dependence of mechanical properties on the kind of beam element and the mesh density is also compared. Based on the obtained results, Youngs modulus and critical buckling load of structures using Timoshenko beams are clearly lower than the Bernoulli beam approach for all chiralities.

Mechanical Buckling Analysis of Single-Walled Carbon Nanotube with Nonlocal Effects

2017 ◽  
Vol 48 ◽  
pp. 85-94 ◽  
Author(s):  
B. Ravi Kumar
Keyword(s):  
Carbon Nanotube ◽  
Nonlinear Problems ◽  
Buckling Load ◽  
Transform Method ◽  
Fourth Degree ◽  
Single Walled Carbon Nanotube ◽  
Critical Buckling Load ◽  
Single Walled Carbon ◽  
Buckling Behavior ◽  
High Degree

In this work Differential Transform Method (DTM) is used to study the buckling behavior of the single walled carbon nanotube (SWCNT). The critical buckling load is being found out up to fourth degree accuracy for different boundary conditions, i.e. Clamped-Clamped, Simply Supported at ends, Clamped Hinged, and Clamped Free. Effect of different nonlocal parameters, different L/d ratio on critical buckling load is being discussed. The DTM is implemented for the nonlocal SWCNT analysis and this yields results with high degree of accuracy. Further, present method can be applied to linear and nonlinear problems.

Numerical Simulation Analysis on Buckling Load of Large Combined Cylindrical Shells

2008 ◽  
Author(s):  
Zhiping Chen ◽  
Ming Zeng ◽  
Chu-Lin Yu ◽  
Jinping Zhu
Keyword(s):  
Numerical Simulation ◽  
Hoop Stress ◽  
Simulation Analysis ◽  
Cylindrical Shells ◽  
Great Influence ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Buckling Behavior ◽  
The Difference ◽  
Almost All

To comply with the uniform-strength theory, almost all large tanks are made by welding unequal-thickness cylindrical shell courses together. This structure can be considered as a kind of geometry imperfection of tank walls, which has a great influence on buckling behavior and critical load of tank walls. To obtain the related critical buckling load and to verify the effect regularity on bulking due to hoop stress in various combined unequal-thickness cylindrical shells, the numerical simulation was adopted to analyze the buckling behavior with different loads. The results show that the characteristic factors of unequal-thickness structure can reduce the critical buckling load significantly, such factors as shell layers and the difference in thickness of adjacent shell courses are the most dominant.

scholarly journals A semi-analytical model on the critical buckling load of perforated plates with opposite free edges

2022 ◽  
pp. 095440622110568
Author(s):  
Weigang Fu ◽  
Bin Wang
Keyword(s):  
Analytical Model ◽  
Perforated Plate ◽  
Beam Theory ◽  
Buckling Load ◽  
Width Ratio ◽  
Geometrical Parameters ◽  
Engineering Structures ◽  
Perforated Plates ◽  
Critical Buckling Load ◽  
Free Edges

Perforated plates are widely used in thin-walled engineering structures, for example, for lightweight designs of structures and access for installation. For the purpose of analysis, such perforated plates with two opposite free edges might be considered as a series of successive Timoshenko beams. A new semi-analytical model was developed in this study using the Timoshenko shear beam theory for the critical buckling load of perforated plates, with the characteristic equations derived. Results of the proposed modelling were compared with those obtained by FEM and show good agreement. The influence of the dividing number of the successive beams on the accuracy of the critical buckling load was studied with respect to various boundary conditions. And the effect of geometrical parameters, such as the aspect ratio, the thickness-to-width ratio and the cutout-to-width ratio were also investigated. The study shows that the proposed semi-analytical model can be used for buckling analysis of a perforated plate with opposite free edges with the capacity to consider the shear effect in thick plates.

Buckling Analysis of a Taper-Taper Adhesive-Bonded Composite Joint

2002 ◽  
Author(s):  
Jack E. Helms ◽  
Guoqiang Li ◽  
Su-Seng Pang
Keyword(s):  
Analytical Model ◽  
Ritz Method ◽  
Compressive Loading ◽  
Beam Theory ◽  
Buckling Load ◽  
Transverse Displacement ◽  
Laminated Beam ◽  
Critical Buckling Load ◽  
Composite Joint ◽  
Bonded Composite

An analytical model of the behavior of an adhesive-bonded taper-taper composite joint under axial compressive loading has been developed using the Ritz Method. The model was based on laminated beam theory. A Fourier series was used to represent the transverse displacement variable and the Ritz method was used to derive an eigenvalue equation for adhesively bonded taper-taper composite joint. The smallest eigenvalue is the critical buckling load. Finite element analyses were performed on two unidirectional laminated beam joints with various taper angles to verify the analytical model. The effect of varying the taper angle, adhesive thickness and adhesive modulus on the critical buckling load were investigated analytically.

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