Stability Analysis of the Stiffened Plate with Rids under the Longitudinal Loads

2011 ◽  
Vol 243-249 ◽  
pp. 279-283
Author(s):  
Yu Zhang
Keyword(s):  
Potential Energy ◽  
Boundary Conditions ◽  
Critical Loads ◽  
Minimum Condition ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Simply Supported ◽  
Total Potential ◽  
The Stability ◽  
Work Done

The stiffened plate with rids was considered as a whole structure. Using energy method the stability of stiffened plates with rids under the longitudinal forces was analyzed. Calculating the potential energy of deformation of plate and that of rids and the work done by the neutral plane forces of plate when the plates were buckled, the formulas of critical loads of the stiffened plate with rids under longitudinal forces were derived from the minimum condition of total potential energy. Using the formulas in this paper engineers can easily calculate the critical loads of the stiffened plate with rids under the boundary conditions: the opposite sides are fixed and the other opposite sides are simply supported, four sides are simply supported. The formula of critical loads of the stiffened plate with rids under other boundary conditions can be derived using the method in this paper.

Stability of laminated composite and sandwich FGM shells using a novel isogeometric finite strip method

2019 ◽  
Vol 37 (4) ◽  
pp. 1369-1395 ◽  
Author(s):  
Mohammad Amin Shahmohammadi ◽  
Mojtaba Azhari ◽  
Mohammad Mehdi Saadatpour ◽  
Saeid Sarrami-Foroushani
Keyword(s):  
Boundary Conditions ◽  
Critical Loads ◽  
Laminated Composite ◽  
Functionally Graded ◽  
Laminated Shells ◽  
Content Type ◽  
Finite Strip ◽  
Strip Method ◽  
Finite Strip Method ◽  
The Stability

Purpose This paper aims to analyze the stability of laminated shells subjected to axial loads or external pressure with considering various geometries and boundary conditions. The main aim of the present study is developing an efficient combined method which uses the advantages of different methods, such as finite element method (FEM) and isogeometric analysis (IGA), to achieve multipurpose targets. Two types of material including laminated composite and sandwich functionally graded material are considered. Design/methodology/approach A novel type of finite strip method called isogeometric B3-spline finite strip method (IG-SFSM) is used to solve the eigenvalue buckling problem. IG-SFSM uses B3-spline basis functions to interpolate the buckling displacements and mapping operations in the longitudinal direction of the strips, whereas the Lagrangian functions are used in transverse direction. The current presented IG-SFSM is formulated based on the degenerated shell method. Findings The buckling behavior of laminated shells is discussed by solving several examples corresponding to shells with various geometries, boundary conditions and material properties. The effects of mechanical and geometrical properties on critical loads of shells are investigated using the related results obtained by IG-SFSM. Originality/value This paper shows that the proposed IG-SFSM leads to the critical loads with an approved accuracy comparing with the same examples extracted from the literature. Moreover, it leads to a high level of convergence rate and low cost of solving the stability problems in comparison to the FEM.

Dilute Aqueous Dispersions of Zro2 And Al2O3

1985 ◽  
Vol 60 ◽  
Author(s):  
Evelyn M. De Liso ◽  
W. Roger Cannon ◽  
A. Srinivasa Rao
Keyword(s):  
Potential Energy ◽  
Total Potential Energy ◽  
Alumina Powder ◽  
Maximum Height ◽  
Colloidal Interactions ◽  
Total Potential ◽  
Particle Size Data ◽  
Theoretical Predictions ◽  
Alumina Composite ◽  
The Stability

AbstractColloidal interactions in a heteroparticulate mixture of zirconia and alumina in water were studied for use in a transformation toughened alumina composite. The microelectrophoresis technique was used to measure the mobility of three zirconia powders and an alumina powder. The electro-phoretic mobility and particle size data were used to calculate total potential energy curves. The maximum height of the total potential energy barrier was used to predict the stability of a zirconia/alumina mixture. Theoretical predictions were compared to experimental results obtained from sedimentation and rheology measurements carried out as a function of pH of the dispersion. For a 5 v/o aqueous zirconia/alumina system stable dispersions were made at pH 3 and pH 5.

DYNAMIC INSTABILITY OF COMPOSITE SKEW PLATES USING BOUNDARY CHARACTERISTIC ORTHOGONAL POLYNOMIALS

2014 ◽  
Vol 06 (06) ◽  
pp. 1450078 ◽  
Author(s):  
ABHINAV KUMAR ◽  
S. K. PANDA ◽  
RAJESH KUMAR
Keyword(s):  
Potential Energy ◽  
Boundary Conditions ◽  
Total Energy ◽  
Shear Deformation ◽  
Dynamic Instability ◽  
Energy Functional ◽  
Total Potential Energy ◽  
Bending Energy ◽  
Total Potential ◽  
Skew Plate

Dynamic instability analysis of laminated composite skew plate for different skew angles subjected to different type of linearly varying in-plane loadings is investigated. The analysis also includes the instability of skew plate under uniform bi-axial in-plane loading. The skew plate structural model is based on higher order shear deformation theory (HSDT), which accurately predicts the numerical results for thick skew plate. The total energy functional is derived for the skew plates from total potential energy and kinetic energy of the plate. The strain energy which is the part of total potential energy contains membrane energy, bending energy, additional bending energy due to additional change in curvature and shear energy due to shear deformation, respectively. The total energy functional is mapped into a square plate over which a set of orthonormal polynomials satisfying the essential boundary conditions is generated by Gram–Schmidt orthogonalization process. Different boundary conditions of skew plate have been correctly incorporated by using Rayleigh–Ritz method in conjunction with Boundary Characteristics Orthonormal Polynomials (BCOPs). The boundaries of dynamic instability regions are traced by the periodic solution of governing differential equations (Mathieu type equations) with period T and 2T. The width of instability region for uniform loading is higher than various types of linearly varying loadings (keeping the same peak intensity). Effect of various parameters like skew angle, aspect ratio, span-to-thickness ratio, boundary conditions and static load factor on dynamic instability has been investigated.

Buckling of a Thin Annular Plate Under Uniform Compression

1958 ◽  
Vol 25 (2) ◽  
pp. 267-273
Author(s):  
N. Yamaki
Keyword(s):  
Boundary Conditions ◽  
Circular Plate ◽  
Critical Loads ◽  
Equilibrium Equation ◽  
Annular Plate ◽  
Elastic Stability ◽  
Infinite Strip ◽  
Uniform Compression ◽  
The Stability

Abstract This paper deals with the elastic stability of a circular annular plate under uniform compressive forces applied at its edges. By integrating the equilibrium equation of the buckled plate, the problem is solved in its most general form for twelve different combinations of the boundary conditions of the edges. For each case cited the lowest critical loads are calculated with the ratio of its radii as the parameter. It is clarified that the assumption of symmetrical buckling, which has been made by several researchers, often leads to the overestimate for the stability of the plate. Discussions for the limiting cases of the circular plate and infinite strip also are included.

Bending of Orthogonally Stiffened Plates

1955 ◽  
Vol 22 (2) ◽  
pp. 267-271
Author(s):  
W. H. Hoppmann
Keyword(s):  
Boundary Conditions ◽  
Experimental Method ◽  
Circular Plate ◽  
Elastic Constants ◽  
Orthotropic Material ◽  
Elastic Moduli ◽  
Unit Area ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Clamped Edge

Abstract In this paper the flexure theory for plates of orthotropic material is applied in the case of orthogonally stiffened plates using an experimental method to determine plate stiffnesses in bending and in twisting. Once these stiffnesses, or elastic moduli, have been determined by test they may be used in calculating bending deflections for plates of identical stiffened construction but any given boundary conditions. As an example, calculated deflections of a stiffened circular plate with clamped edge are compared with those which were determined experimentally. It is also demonstrated that the theory can be applied to the case of vibration of a stiffened plate if in addition to the orthotropic elastic constants the weight per unit area of the plate is determined. The various experimental results show considerable promise for use of the proposed combination of theory and experimental method in the analysis of both statically and dynamically loaded plates with attached stiffeners.

Effects of Shearing Loads and In-Plane Boundary Conditions on the Stability of Thin Tubes Conveying Fluid

1979 ◽  
Vol 46 (4) ◽  
pp. 779-783 ◽  
Author(s):  
J. Tani ◽  
H. Doki
Keyword(s):  
Boundary Conditions ◽  
Fourier Integral ◽  
Integral Theory ◽  
Plane Boundary ◽  
Simply Supported ◽  
Thin Walled ◽  
Shell Equation ◽  
Divergence Velocity ◽  
The Stability ◽  
Conveying Fluid

The hydroelastic stability of short, simply supported, thin-walled tubes conveying fluid is examined with an emphasis on the effects of shearing loads and in-plane boundary conditions. The Donnell shell equation is used in conjunction with linearized, potential flow theory. The solution is obtained by using Fourier integral theory and Galerkin’s method. It is found that an increase of the shearing load reduces the critical divergence velocity and raises the corresponding number of circumferential waves. A change in the in-plane boundary conditions exerts the significant effect on the critical divergence velocity of short tubes.

scholarly journals Numerical analysis of stability of the stiffened plates subjected aliquant critical loads

2020 ◽  
Vol 16 (1) ◽  
pp. 54-61
Author(s):  
Gaik A. Manuylov ◽  
Sergey B. Kositsyn ◽  
Irina E. Grudtsyna
Keyword(s):  
Numerical Analysis ◽  
Critical Loads ◽  
Geometric Nonlinearity ◽  
Compressive Load ◽  
Stiffened Plates ◽  
Geometric Imperfections ◽  
Initial Geometric Imperfections ◽  
Analysis Of Stability ◽  
The Stability

The aim of the work is to research the precritical and postcritical equilibrium of the stiffened plates subjected aliquant critical loads. Methods. The finiteelement complex MSC PATRAN - NASTRAN was used in the paper. To simulate the plates, flat four-node elements were used. Calculations taking into account geometric nonlinearity were carried out. The material of the shells was considered absolutely elastic. Results. A technique has been developed to study the stability of reinforced longitudinally compressed plates; the critical forces of the stiffened plates of various thicknesses had been calculated. Graphs of deflections dependences on the value of the compressive load had been constructed. The influence of initial geometric imperfections on the value of the critical loads for stiffened plates has been investigated.

scholarly journals Linear Magnitudes Estimated via Expense of Incompletely Defined Potential Energy were Likely Overestimated by over 3.48 %

2014 ◽  
Vol 32 ◽  
pp. 32-41
Author(s):  
Jakub Czajko
Keyword(s):  
Differential Geometry ◽  
Potential Energy ◽  
Total Potential Energy ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Total Rate ◽  
Central Force Field ◽  
Total Potential ◽  
Definition Of ◽  
Work Done

Since former definition of work done by any radial/center-bound (central) force field (and consequently thus also of the corresponding to it expense of potential energy of the field) was incompletely defined (so that these two basic notions were valid only for purely radial phenomena), some indirect estimations of those linear magnitudes that relied on the former (incomplete yet always presumed as total) potential energy may have been overestimated. New, operationally complete and thus mathematically lawful definition of total rate of work done by the field implies presence of a certain (experimentally observed but formerly quite unanticipated and thus routinely unaccounted for) nonradial angular contribution to the total potential energy. Hence some previous calculations of those linear magnitudes, which were indirectly estimated via expense of potential energy spent on the work done, may have been quite inadvertently overrated by over 3.48 %. This was because the extra potential energy that is spent on twisting the path that is deflected by the source of the field was disregarded in the former, incomplete definition of work done, even though such nonradial twisting is generally required by proven Frenet-Serret formulas of differential geometry. This present assessment is based upon purely mathematical premises, but similar prior nonradial angular formula utilized here has already retrodicted the 10.56 % excess over Einstein‟s prediction of deflection of light that was observed in several unbiased experiments, and it has reconciled some other experiments that could neither be explained nor reconciled by general theory of relativity, which, as radial by design, does not account for nonradial or mixed phenomena

Stability Analysis of an Imperfect Slender Web Subjected to the Shear Load

2016 ◽  
Vol 837 ◽  
pp. 52-57
Author(s):  
Martin Psotny
Keyword(s):  
Stability Analysis ◽  
Potential Energy ◽  
Total Potential Energy ◽  
Iteration Algorithm ◽  
Buckling Mode ◽  
Total Potential ◽  
Nonlinear Equilibrium ◽  
The Stability ◽  
Ansys System ◽  
Raphson Iteration

The stability analysis of an imperfect slender web subjected to the shearing load is presented, a specialized code based on FEM has been created. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To obtain the nonlinear equilibrium paths, the Newton-Raphson iteration algorithm is used. Corresponding levels of the total potential energy are defined. The peculiarities of the effects of the initial imperfections are investigated. Special attention is paid to the influence of imperfections on the post-critical buckling mode. Obtained results are compared with those gained using ANSYS system.

scholarly journals Buckling And Postbuckling Of An Imperfect Plate Subjected To The Shear Load

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Martin Psotný
Keyword(s):  
Potential Energy ◽  
Total Potential Energy ◽  
Iteration Algorithm ◽  
Shear Load ◽  
Buckling Mode ◽  
Total Potential ◽  
Nonlinear Equilibrium ◽  
The Stability ◽  
Ansys System ◽  
Raphson Iteration

Abstract The stability analysis of an imperfect plate subjected to the shear load is presented. To solve this problem, a specialized computer program based on FEM has been created. The nonlinear finite element method equations are derived from the variational principle of minimum of total potential energy. To obtain the nonlinear equilibrium paths, the Newton-Raphson iteration algorithm is used. Corresponding levels of the total potential energy are defined. Special attention is paid to the influence of imperfections on the post-critical buckling mode. Obtained results are compared with those gained using ANSYS system.

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