Thermal Buckling Research Papers - Academia.edu (original) (raw)

This work deals with the investigation of a steel thin-walled C-column subjected to compression due to temperature increase. These experimental studies of the compressed columns in post-buckling state were conducted to determine their load-carrying capacity. To ensure appropriate supports and keeping of columns, plates with grooves were constructed. The tests of the columns’ compression for different preloads were carried out. By comparing the experiment results, numerical calculations based on the finite element method (FEM) and the semi-analytical method (SAM) of solution were performed. The computations were executed with the use of full material characteristics with consideration of large strains and deflections. Furthermore, while observing the deformation of columns, a non-contact Digital Correlation ARAMIS® system was employed whose calculated results of deformations are very close to the results of the numerical method. The paper revealed that maximum recorded loads under te...

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- Engineering, Materials Science, Structural Engineering, Materials

The present study investigates buckling in functionally graded material (FGM) beams when exposed to a temperature rise. The proposed FGM beams have arbitrary edge supports that are modeled by rotational and translational springs. The mechanical properties are assumed to vary continuously across the thickness direction according to a simple four-parameter power law. To obtain the critical value of temperature, the governing equilibrium equations are extracted based on Timoshenko beam theory, using the assumption of Von-Karman nonlinearity for the physical neutral surface concept. The equations are further solved by Fourier series expansion via Stokes' transformation technique. Numerical examples are provided to demonstrate the accuracy and reliability of the proposed method. The influence of two models of metal-ceramic distribution across the thickness (symmetrical and unsymmetrical ones) on the response of the beam in thermal buckling of FG beam is investigated. It is observed that, the critical buckling temperature rises more for symmetrical model of FGM beam with respected to unsymmetrical one. Also, increasing the translational and rotational spring coefficient makes the beam stiffer; consequently, the critical buckling temperature is increased.

In this paper, we propose a thermal buckling analysis of a functionally graded (FG) circular plate exhibiting polar orthotropic characteristics and resting on the Pasternak elastic foundation. The plate is assumed to be exposed to two kinds of thermal loads, namely, uniform temperature rise and linear temperature rise through thickness. The FG properties are assumed to vary continuously in the direction of thickness according to the simple power law model in terms of the volume fraction of two constituents. The governing equilibrium equations in buckling are based on the Von-Karman nonlinearity. To obtain the critical buckling temperature, we exploit a semi-numerical technique called differential transform method (DTM). This method provides fast accurate results and has a short computational calculation compared with the Taylor expansion method. Furthermore, some numerical examples are provided to consider the influence of various parameters such as volume fraction index, thicknessto-radius ratio, elastic foundation stiffness, modulus ratio of orthotropic materials and influence of boundary conditions. In order to predict the critical buckling temperature, it is observed that the critical temperature can be easily adjusted by appropriate variation of elastic foundation parameters and gradient index of FG material. Finally, the numerical results are compared with those available in the literature to confirm the accuracy and reliability of the DTM to determine the critical buckling temperature.

- by Jafar Eskandari Jam
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- Mathematics, Solid Mechanics, Genetic Algorithm, Optimization Problem
- by Dheeraj Varma
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- Engineering, Materials Science, Clutch, Engineering Technology
- by Yuwaraj Marotrao Ghugal
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- Engineering, Materials Science, Structural Engineering

In the present study, the electro-mechanical responses of smart laminated composite plates with piezoelectric materials are derived using a two-dimensional (2 D) displacement-based non-polynomial higher-order shear deformation theory. The kinematics of the mathematical model incorporates the deformation of laminates which account for the effects of transverse shear deformation and a non-linear variation of the in-plane displacements using inverse sine hyperbolic function of the thickness coordinate. The equilibrium equations are obtained using the minimization of energy principle known as the principle of minimum potential energy (PMPE) which is also based on a variational approach and the solutions are obtained using Navier’s solution technique for diaphragm supported smart laminated composite plates. The responses obtained in the form of deflection and stresses are compared with three dimensional (3 D) solutions and also with different polynomial and non-polynomial based higher-or...

- by Dr. Rosalin Sahoo
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- Mechanical Engineering, Materials Science

In the present work, the effect of smart shape-memory alloys on thermal buckling and post-buckling of monoclinic and unidirectional composite panels has been investigated. The aerodynamic pressure applied to the system was modeled using the piston theory method. The effect of thermal heating for ultrasonic flows was also estimated from the reference temperature method. The panel is modeled nonlinearly with large deformations based on Van Karmen's theory. The obtained results show that the shape-memory alloy was able to increase the critical temperature of thermal buckling. The effect of the arrangement of composite layers on increasing the thermal buckling temperature was also studied. The results show that the amount of thermal deflection is greatly reduced due to the use of this alloy. Also, in the higher temperature differences, the rate of reduction of the panel increases.
In this work, the effects of thermal stress on buckling and thermal buckling in a rectangular composite panel with hinge-hinge boundary conditions were investigated. Also, the effect of shape retention alloy in controlling these two phenomena has been studied. The shape memory alloy wire was placed in martensitic mode to apply a compressive force to the panel to control the heating and aerodynamic forces after changing the phase to austenite. The governing equations of the system were extracted through the layer theory method to show the effects of in-plane displacements better.
Investigations on the effect of different layers (symmetry effects and arrangement angle of composite sheets) were performed to investigate thermal buckling. According to the obtained results, the layer arrangement of plates (0.90 / 0.90), (-45.45), (30/60), and (0.90 / 90.0), respectively, had the greatest effect on raising the critical temperature of thermal buckling in dimensional ratios equal to or greater than one. This shows that the symmetry of the arrangements has a greater effect than the angle of the arrangements. Examining the buckling diagrams for the effect of a shape memory alloy, it can be concluded that by placing this alloy in the composite panel, in addition to raising the buckling temperature, this alloy has a greater effect on displacement control by increasing the temperature after the critical buckling temperature.

- by Giuseppe Rega
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- Engineering, Structural Engineering, Mathematical Sciences, Physical sciences
- by Massood Mofid
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- Engineering, Structural Engineering, Vibration, Boundary Value Problem

In the present study, an accurate Bézier based multi-step method is developed and implemented to find the nonlinear vibration and post-buckling configurations of Euler-Bernoulli composite beams reinforced with graphene nano-platelets (GnP). The GnP is assumed to be randomly and uniformly dispersed in the composite mixproportion, with a random checkerboard configuration. Therefore, a probabilistic model together with an efficient simulation technique is proposed to find the effective moduli of a matrix reinforced GnP. It is worth noting that the presented micro-mechanics model found by the employed Monte-Carlo simulation matches exactly the experimental data and predicts the composite elastic constants more accurate than that found from other common methods, including the Halpin-Tsai theory. Also, for mathematical simplification, the composite beam in-plane inertia is neglected. The presented multi-step method is based on Burnstein polynomial basis functions while shows interesting potential to provide robust solutions for various initial and boundary value problems. It is found that adding a relatively low content of GnP would drastically increase the composite elastic constants, particularly in the transverse direction to fiber. In addition, the numerical results are compared with those provided by exact analytical solutions, where the stability of results suggests the effectiveness of the presented methodology.

- by Hossein Kabir
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- Graphene, Numerical Analysis, Composite Materials, Nanotechnology

This paper studies mechanical buckling of functionally graded beams subjected to axial compressive load that is simply supported at both ends lies on a continuous elastic foundation. The displacement field of beam is assumed based on Engesser-Timoshenko beam theory. Applying the Hamilton's principle, the equilibrium equation is established. The influences of dimensionless geometrical parameter, functionally graded index and foundation coefficient on the critical buckling load of beam are presented. To investigate the accuracy of the present analysis, a compression study is carried out with a known data.

- by Mostafa Baghani
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- Engineering, Materials Science, Structural Engineering, Finite element method
- by Morteza Dardel
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- Mechanical Engineering, Materials Science, Vibration, Shape Memory Alloy
- by Cuong Le Thanh
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- Engineering, Mechanical Engineering, Materials Science, Structural Engineering
- by Hamed Bagheri
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- Mechanical Engineering, Mathematics, Materials Science, Buckling

In this study, free vibration behavior of a multilayered symmetric sandwich beam made of functionally graded materials (FGMs) with variable cross section resting on variable Winkler elastic foundation are investigated. The elasticity and density of the functionally graded (FG) sandwich beam vary through the thickness according to the power law. This law is related to mixture rules and laminate theory. In order to provide this, a 50-layered beam is considered. Each layer is isotropic and homogeneous, although the volume fractions of the constituents of each layer are different. Furthermore, the width of the beam varies exponentially along the length of the beam, and also the beam is resting on an elastic foundation whose coefficient is variable along the length of the beam. The natural frequencies are computed for conventional boundary conditions of the FG sandwich beam using a theoretical procedure. The effects of material, geometric, elastic foundation indexes and slenderness ratio...

- by Ersin Demir
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- Materials Science, Structural Engineering, Finite element method, Vibration

In this research, a free vibration of unidirectional composite laminated plate with different holes shape effect investigation is done experimentally and numerically. The natural frequency and deflection response of a unidirectional composite plate are studied with different holes shape effect as (rectangular or triangular or square or ellipse or circular shape, for simply supported and clamped composite laminated plate boundary conditions. This effect is studied for different shape cutout with the same area of different cutout shapes. The results of natural frequency evaluated by experimental work are compared with those evaluated by numerical method using a finite element method, (ANSYS program Ver. 14). The deflection of composite laminated plate with different holes effect is evaluated using finite element method. The results showed that the maximum natural frequency of unidirectional composite plate occurs at the clamped supported boundary composite plate with circular cutout. ...

- by Abdullah Mohsin
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A beam model for thermal buckling analysis of a bimetallic box beam is presented. The Euler–Bernoulli–Vlasov beam theory is employed considering large rotations but small strains. The nonlinear stability analysis is performed using an updated Lagrangian formulation. In order to account for the thermal effects of temperature-dependent (TD) and temperature-independent (TID) materials, a uniform temperature rise through beam wall thickness is considered. The numerical results for thin-walled box beams are presented to investigate the effects of different boundary conditions, beam lengths and material thickness ratios on the critical buckling temperature and
post-buckling responses. The effectiveness and accuracy of the proposed model are verified by means of comparison with a shell model. It is revealed that all of the abovementioned effects are invaluable for buckling analysis of thin-walled beams under thermal load. Moreover, it is shown that the TD solutions give lower values than the TID one, emphasizing the importance of TD materials in beams.

- by Sandra Kvaternik Simonetti and +1
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- Thermal Buckling, FEM Modelling and Numerical Simulation, Thin-Walled

This paper presents a beam model for a geometrically nonlinear stability analysis of the composite beam-type structures. Each wall of the cross-section can be modeled with a different material. The nonlinear incremental procedure is based on an updated Lagrangian formulation where in each increment, the equilibrium equations are derived from the virtual work principle. The beam model accounts for the restrained warping and large rotation effects by including the nonlinear displacement field of the composite cross-section. First-order shear deformation theories for torsion and bending are included in the model through Timoshenko’s bending theory and a modified Vlasov’s torsion theory. The shear deformation coupling effects are included in the model using the six shear correction factors. The accuracy and reliability of the proposed numerical model are verified through a comparison of the shear-rigid and shear-deformable beam models in buckling
problems. The obtained results indicated the importance of including the shear deformation effects at shorter beams and columns in which the difference that occurs is more than 10 percent.

- by Damjan Banić and +1
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- Composite Materials, Nonlinear Stability, Beam Column Model, Thin-Walled

The dynamic behavior of functionally graded (FG) sandwich beams resting on the Pasternak elastic foundation under an arbitrary number of harmonic moving loads is presented by using Timoshenko beam theory, including the significant effects of shear deformation and rotary inertia. The equation of motion governing the dynamic response of the beams is derived from Lagrange’s equations. The Ritz and Newmark methods are implemented to solve the equation of motion for obtaining free and forced vibration results of the beams with different boundary conditions. The influences of several parametric studies such as layer thickness ratio, boundary condition, spring constants, length to height ratio, velocity, excitation frequency, phase angle, etc., on the dynamic response of the beams are examined and discussed in detail. According to the present investigation, it is revealed that with an increase of the velocity of the moving loads, the dynamic deflection initially increases with fluctuations...

- by Monsak Pimsarn
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- Physics, Mechanics, Vibration, Moving Load

The current investigation deals with an analytical formulation and solution procedure for the thermal stability characteristics of piezomagnetic nano-sensors and nano-actuators considering the flexomagnetic effects and geometrical imperfection. Piezo-flexomagnetic nano-plate strips with the mid-plane initial rise are subjected to external uniform, linear, and nonlinear temperature rise loading across the thickness. The nonlinear sizedependent governing equations are derived within the framework of the first-order shear deformation plate theory, nonlocal strain gradient theory and considering the nonlinear von-Kármán strains. The proposed closed-form solutions and the obtained results are validated with the available data in the literature. The calculated buckling and post-buckling temperatures of piezo-flexomagnetic nano-plate strips are shown to be dependent on several factors including the scaling parameters, plate slenderness ratio, mid-plane initial rise, different temperature distributions, and scalar magnetic potential. The presented closed-form solutions and numerical results can serve as benchmarks for future analyses of piezo-flexomagnetic nano-sensors and nano-actuators.

Static analysis of Functionally Graded (FG) beams is studied by the Complementary Functions Method (CFM). The material properties, Young’s modulus, of the straight beams, are graded in the thickness direction based on a power law distribution while the Poisson’s ratio is supposed to be constant. Governing equations of the considered problem are obtained with the aid of minimum total potential energy principle based on Timoshenko’s beam theory (FSDT). The main purpose of this paper is the infusion of the CFM to the static analysis of FG straight beams. The effectiveness and accuracy of the proposed method are confirmed by comparing its numerical results with those available in the literature. Application of this efficient method provides accurate results of static response for FGM beams with different variations of material properties in the thickness of the beam.

- by Timuçin Aslan
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- Physics
- by Timuçin Aslan
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- Engineering, Physics, Structural Engineering, Vibration

In this present study composite plates with cut-outs have been studied for their buckling strength when subjected to different shape and size of cut-out, ply orientation, aspect ratio, skewness, etc. The best suited hole-area ratio with different constraints is studied and found here. The ABAQUS software is used for the analysis. Eight-Node Shell element with five degrees of freedom (S8R5) is used throughout the analysis. Five different types of layup sequences of the laminate combined with five different types of loading are considered for the analysis. Two different types of material have also been used. Five different skew angles have been used to analyze the buckling behavior under different loading conditions. Comprehensive results have been obtained in this study which is presented accordingly. IndexTerms – Laminate, Composite, Plate, Cut-out, ABAQUS, Buckling load, Skew.

- by kapil soni
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- by Abdellatif Abdo
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This work studies the buckling and free vibration behavior of Shape Memory Alloy Hybrid Composite (SMAHC) sandwich beams under a thermal environment. The sandwich beams consist of layers reinforced with SMAs and a FGM core, and they are simply supported at both ends. The higher order theory is combined with the Minimum Potential Energy principle or Hamilton principle to derive the governing equations of the thermal buckling and thermal vibration problems, respectively. The material properties of the beam are assumed as temperature-independent (TID) or temperature-dependent (TD). In the last case, two different types of thermal distribution are considered, namely a uniform and a linear distribution. The results based on the proposed formulation are verified against the reference literature, with a very good matching. A parametric study checks for the influence of different effective parameters such as thickness-to-length ratios, volume fraction powers, initial strain, volume fraction...

- by MOHAMMAD nejati
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- Materials Science, Structural Engineering, Vibration, Buckling
- by Goran Turkalj
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- Engineering, Materials Science, Structural Engineering, Finite element method
- by Hadi Babaei
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- Mechanical Engineering, Materials Science, Buckling, Thermal

Among all the natural fiber, leather fiber is one of the animal fibers which is bearing hydrophilic and hydrophobic functional group. Leather is tanned with different types of chemicals and scraped crust leather containing chemical are coming from the leather industry after preparing footwear and leather products. In this research an attempt was taken to prepare composite with waste scrape crust leather. Leather fiber reinforced polyester resin based composites were prepared by wet layup method. Polyester content in the composite was varied from 100 ml to 40 ml and benzoyl peroxide was used as a radical initiator. Tensile strength (TS), Young modulus and elongation at break (Eb) were measured. Tensile strength found to increase from 9.80 MPa to 10.85 MPa. Young's modulus was found highest in 70:5 ratios and it was 158.16 Mpa. Scraped crust reinforced composite will reduce the environmental pollution. So it can be concluded that scraped crust leather reinforced composite was found to have better result than matrix and reinforced material.

- by Mohammad Jakir Hossain Khan
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- Solid Waste Management, leather Industry

The possibility of designing composite panels with non-uniform stiffness properties offers a chance for achieving highly-efficient configurations. This is particularly true for buckling-prone structures, whose response can be shaped through a proper distribution of the membrane and bending stiffnesses. The thermal buckling behaviour of composite panels is among the aspects that could largely benefit from the adoption of a variable-stiffness design, but, in spite of that, it has rarely been addressed. The paper illustrates a semi-analytical approach for evaluating the thermal buckling response of variable-stiffness plates (VSP) by considering different boundary conditions. The formulation relies upon the method of Ritz and a variable-kinematic approach, leading to a computationally efficient implementation, which is particularly useful for exploring the larger design spaces, typical of variable-stiffness configurations. Due to the possibility of choosing the underlying kinematic appr...

- by Lorenzo Dozio
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- Materials Science, Structural Engineering, Composites, Kinematics

The behavior of thin rectangular perforated plates under the action of uniform compressive deformation is studied using finite element analysis. The central holes are either circular holes or square holes. The effects of plate-support conditions, plate aspect ratio, hole geometry, and hole size on the buckling strengths of the perforated plates was studied. The results show that for the same plate weight density, the buckling strengths of the plates with square holes generally surpass those of the plates with circular holes over the range of hole sizes.

- by Mohamed BENGUEDIAB
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- by Mohamed BENGUEDIAB
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- Mechanical Engineering, Materials Science, Structural Engineering, Critical

Recently, the functionally graded (FG) concept used in different mechanical engineering applications has become an important solution for delamination problems due to the brutal transition of material composition. The specific goal of this study is the determination of theoretical solution of the critical buckling temperature for rectangular FG plates with a ceramic coating, subjected to the sinusoidal and power law temperature rises. By applying the Galerkin method, the critical buckling load model is obtained. Based on obtained results, the effect of coated functionally graded parameters, namely the coating thickness, the power law index, the initial imperfections and the temperature rise type on the thermal buckling is discussed. This study is useful for the design engineers to choose the coating thickness, the geometrical parameters and the optimum composition as desired to assure the stability of structures subjected to a non-uniform temperature distribution. Key-words: Functio...

- by abdellatif rahmouni
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- by ANIRBAN MITRA
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- Engineering, Mechanical Engineering, Civil Engineering, Aerospace Engineering
- by Gennadi Mikhasev
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- Materials Science, Structural Engineering, Finite element method, Buckling

The powerful extended Kantorovich method (EKM) originally proposed by Kerr in 1968 is generalized to obtain a three-dimensional coupled piezoelasticity solution of smart piezoelectric laminated plates in cylindrical bending. Such solutions are needed to accurately predict the edge effects in these laminates under electromechanical loading. The Reissner-type mixed variational principle extended to piezoelasticity is used to develop the governing equations in terms of displacements, electric potential as well as stresses and electric displacements. It allows for exact satisfaction of the boundary conditions, including the non-homogeneous ones at all points. An n -term solution generates a set of 11 n algebraic ordinary differential equations in the inplane direction and a similar set in the thickness direction for each lamina, which are solved in closed form. The multi-term EKM is shown to predict the coupled electromechanical response, including the edge effects, of single-layer piez...

- by poonam kumari
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- Engineering, Materials Science, Mathematical Sciences, Physical sciences
- by Radoslaw Mania
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- Mathematics

In the present work, new inverse hyperbolic higher-order shear deformation theory (IHHSDT) is proposed and implemented for buckling analysis and free vibration analysis of porous Functionally Graded Material (FGM) plate on the foundation. The proposed theory follows the approximately parabolic distribution of the transverse stresses through the plate thickness and satisfies the conditions of continuity and differentiability. Three different types of porosity distribution considered. Governing differential equations (GDEs) of the plate is developed in the framework of proposed theories by Hamilton’s principle. Multiquadrics radial basis function (MQ-RBF) based Meshfree method used for discretizing the GDEs. The result obtained by the present theory is validated with the three-dimensional elastic theory and other available solutions in the literature to ensure the efficacy and accuracy of the proposed theory. Numerical results obtained for buckling and free vibration for porous FGM pl...

- by Jeeoot Singh
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- Materials Science, Structural Engineering, Vibration, Porosity

This research presents a new model for vibration analysis of thick laminated plates on a non-homogeneous elastic foundation by the Dynamic Stiffness Method(DSM). The non-homogeneous foundation consists of multi-segment Winkler-type and Pasternak-type elastic foundation. The Dynamic Stiffness Matrices using the First ShearDeformation Theory (FSDT) are constructed for cross-ply thick composite plates. A computer program is written using the present formulation for calculating natural frequencies and harmonic response of composite plates subjected to various types of boundary conditions. Numerical results are validated by comparison with available results in the literature and with Finite Element Method (FEM). Different test cases make evidence the advantages of the present model: higher precision, less data storage, less computing time and studied frequency range extended.

- by Dinh Khanh Ninh
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- Engineering, Structural Engineering, Vibration, Stiffness
- by Antonio Battista
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- Mathematics, Applied Mathematics, Mathematical Physics, Timoshenko beam theory
- by Patrick Shipman
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- Engineering, Mathematics, Linear Elasticity, Pattern Formation
- by Loc Tran
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- Engineering, Materials Science, Structural Engineering, Finite element method

This paper presents a methodological approach based on the homotopy and perturbation methods for thermal buckling and post-buckling analyses of the anisotropic laminated plates with temperature dependent properties. A power law distribution in terms of temperature is used and the structure is subjected to a uniform temperature variation. A mathematical formulation that may account for various temperature dependent models is elaborated. Power series expansions of the displacement and the temperature are developed and the finite element method is used for numerical solutions. The critical buckling load and the post-buckling equilibrium path of plates under thermal loading are investigated. The effects of temperature dependent properties, structure geometry and boundary conditions on the thermal buckling and post-buckling behaviours are evaluated through parametric studies.

- by Lahcen AZRAR
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- Engineering, Materials Science, Structural Engineering, Finite element method
- by Mohammad Talha
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- Finite element method, Vibration, Nonlinear system
- by Tarun Kant
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- Engineering, Materials Science, Composite structures
- by Fakhreddine Dammak
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- Materials Science, Buckling