Delamination Effects on Composite Shells

1990 ◽  
Vol 112 (3) ◽  
pp. 336-340 ◽  
Author(s):  
Fu-Kuo Chang ◽  
Zafer Kutlu
Keyword(s):  
Shear Fracture ◽  
Strain Energy Release ◽  
Analytical Investigation ◽  
Buckling Load ◽  
Composite Shells ◽  
Delamination Growth ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Crack Tips ◽  
Updated Lagrangian

An analytical investigation was performed to study the effect of delamination on the response of cylindrical composite shells subjected to external loadings. It was of particular interest to determine the buckling load and the post-buckling behavior of externally pressurized cylindrical composite shells containing delaminations. An analytical model was developed that consists of a structural analysis for calculating the global deformations of the structures and a fracture analysis for determining the delamination growth in the structures. A nonlinear finite element code based on the updated Lagrangian formulation was developed for the model. Based on the results of calculations, it was found that delamination can significantly affect the buckling load and response of cylindrical composite shells subjected to externally pressurized loadings, depending upon the initial length and location of the delamination, ply orientation and laminate curvature. The calculated strain energy release rate at the crack tips indicates that delamination growth occurs in the wake of buckling due to Mode II shear fracture.

Buckling and Post Buckling Behavior of a Transversely Stiffened Ship Hull Model

1964 ◽  
Vol 8 (04) ◽  
pp. 7-21
Author(s):  
H.G. Schultz
Keyword(s):  
Reasonable Agreement ◽  
Ship Hull ◽  
Buckling Load ◽  
Experimental Results ◽  
Postbuckling Behavior ◽  
Pure Bending ◽  
Box Girder ◽  
Buckling Behavior ◽  
Theoretical Investigations ◽  
Post Buckling

In the paper presented the behavior of a transversely formed box-girder model subjected to pure bending is discussed, where the deck plating of the model is loaded above the buckling load. The experimental results obtained are in reasonable agreement with theoretical investigations and show the influence of fabrication initiated plate deflections on the buckling and postbuckling behavior of the deck plating clearly. A method is suggested for determining the buckling load of plates having large initial deformations.

On the Post-Buckling Behavior of Reinforced Composite Shells

1990 ◽  
Vol 34 (03) ◽  
pp. 207-211
Author(s):  
Victor Birman
Keyword(s):  
Sufficient Conditions ◽  
Axial Loading ◽  
Dynamic Buckling ◽  
General Analysis ◽  
Composite Shells ◽  
Stiffened Shells ◽  
Reinforced Composite ◽  
Buckling Behavior ◽  
Axisymmetric Buckling ◽  
Post Buckling

The problem of post-buckling behavior of composite cylindrical shells reinforced in the axial and circumferential directions and subject to axial loading is considered. The equations of equilibrium of an imperfect shell are formulated in terms of displacements. Then the sufficient conditions of imperfection in sensitivity for both static and dynamic buckling problems are formulated. This general analysis is applied to a particular case of axisymmetric buckling of ring-stiffened shells which appear to be practically imperfection-insensitive.

Initial Post-buckling Behavior of Thick Rings Under Uniform External Hydrostatic Pressure

1995 ◽  
Vol 62 (2) ◽  
pp. 338-345 ◽  
Author(s):  
Lei Fu ◽  
A. M. Waas
Keyword(s):  
Hydrostatic Pressure ◽  
Shear Deformation ◽  
Buckling Load ◽  
Deformation Analysis ◽  
Two Dimensional ◽  
Composite Ring ◽  
Buckling Behavior ◽  
Buckling Stability ◽  
Post Buckling ◽  
Beam Type

The initial post-buckling behavior of thick rings under external uniform hydrostatic pressure is investigated. In the analysis, no assumptions are placed upon the relative magnitudes of the elongations and rotations, and the ring is assumed to be elastic and extensional. The importance of including certain nonlinear terms in the initial post-buckling stability analysis and the effects of nonzero shearing strains on the buckling load and the initial post-buckling stability are examined. It is shown that the classical Kirchhoff assumptions, when employed for a ring lead to nonvanishing through thickness strains, εzz and εzθ, with the latter being proportional to the through thickness coordinate z. An approximate first order shear deformation analysis and a two-dimensional elasticity analysis (without beam-type kinematical assumptions) of the initial post-buckling behavior of thick rings are presented and the thickness effects on the buckling load and the initial post-buckling behavior are examined. The formulation for the composite ring was reduced to that of an isotropic ring and the results thus obtained were compared with published one-dimensional results in the literature. It is found from both the shear deformation and the two-dimensional analysis that the initial post-buckling behavior of the isotropic ring and the composite rings studied are stable. The influence of thickness on the degree of stability in the immediate post-buckling response is characterized.

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.

Nonlinear analysis of stability for imperfect eccentrically stiffened FGM plates under mechanical and thermal loads based on FSDT. Part 2: Numerical results and discussions

2015 ◽  
Vol 37 (4) ◽  
pp. 251-262
Author(s):  
Dao Van Dung ◽  
Nguyen Thi Nga
Keyword(s):  
Shear Deformation ◽  
Volume Fraction ◽  
Plate Theory ◽  
Buckling Load ◽  
Geometrical Parameters ◽  
Thermal Loads ◽  
First Order ◽  
Elastic Foundations ◽  
Buckling Behavior ◽  
Post Buckling

Based on the first-order shear deformation plate theory (FSDT), the smeared stiffeners technique and Galerkin method, the analytical expressions to determine the static critical buckling load and analyze the post-buckling load-deflection curves of FGM plates reinforced by FGM stiffeners resting on elastic foundations and subjected to in-plane compressive loads or thermal loads are established in part 1. In this part, we will use them to study the effects of temperature, stiffener, volume fraction index, geometrical parameters, elastic foundations on the buckling and post-buckling behavior of plates. In addition, the results in comparisons between the classical plate theory (CPT) and the first order shear deformation theory (FSDT) also are carried out and shown that the buckling and post-buckling behavior of more thick plate should be studied by FSDT.

A study on non-linear post-buckling behavior of tapered Timoshenko beam made of functionally graded material under in-plane thermal loadings

2016 ◽  
Vol 52 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Amlan Paul ◽  
Debabrata Das
Keyword(s):  
Functionally Graded Material ◽  
Timoshenko Beam ◽  
Temperature Rise ◽  
Functionally Graded ◽  
Buckling Load ◽  
Uniform Temperature ◽  
Buckling Behavior ◽  
Non Linear ◽  
Graded Material ◽  
Post Buckling

In the present work, the non-linear post-buckling load–deflection behavior of tapered functionally graded material beam is studied for different in-plane thermal loadings. Two different thermal loadings are considered. The first one is due to the uniform temperature rise and the second one is due to the steady-state heat conduction across the beam thickness leading to non-uniform temperature rise. The governing equations are derived using the principle of minimum total potential energy employing Timoshenko beam theory. The solution is obtained by approximating the displacement fields following Ritz method. Geometric non-linearity for large post-buckling behavior is considered using von Kármán type non-linear strain-displacement relationship. Stainless steel/silicon nitride functionally graded material beam is considered with temperature-dependent material properties. The validation of the present work is successfully performed using finite element software ANSYS and using the available result in the literature. The post-buckling load–deflection behavior in non-dimensional plane is presented for different taperness parameters and also for different volume fraction indices. Normalized transverse deflection fields are presented showing the shift of the point of maximum deflection for various deflection levels. The results are new of its kind and establish benchmark for studying non-linear thermo-mechanical behavior of tapered functionally graded material beam.

Rotating Nanorod with Clamped Ends

2015 ◽  
Vol 15 (03) ◽  
pp. 1450050 ◽  
Author(s):  
Teodor M. Atanackovic ◽  
Branislava N. Novakovic ◽  
Zora Vrcelj ◽  
Dusan Zorica
Keyword(s):  
Angular Velocity ◽  
Critical Load ◽  
Nonlocal Elasticity ◽  
Analytical Investigation ◽  
Classical Solutions ◽  
Governing Equations ◽  
Nonlocality Parameter ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Compressive Axial Force

This paper presents an analytical investigation on the buckling and post-buckling behavior of rotating nanorods subjected to axial compression and clamped at both ends. The nonlinear governing equations are derived based on the classical Euler–Bernoulli theory and Eringen's nonlocal elasticity model. The critical load parameters such as angular velocity and compressive axial force are determined for given values of nonlocality parameter. The validity, convergence and accuracy of the solutions are established by comparing them with known classical solutions. The numerical results show that an increase in the nonlocality parameter gives rise to an increase in post-buckling deformation.

Buckling Behavior of Tire Breaker Structure

1983 ◽  
Vol 11 (1) ◽  
pp. 3-19
Author(s):  
T. Akasaka ◽  
S. Yamazaki ◽  
K. Asano
Keyword(s):  
Elastic Foundation ◽  
Elastic Moduli ◽  
Wave Length ◽  
Bending Moment ◽  
Experimental Results ◽  
Automobile Tire ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Steel Cord ◽  
Interlaminar Shear

Abstract The buckled wave length and the critical in-plane bending moment of laminated long composite strips of cord-reinforced rubber sheets on an elastic foundation is analyzed by Galerkin's method, with consideration of interlaminar shear deformation. An approximate formula for the wave length is given in terms of cord angle, elastic moduli of the constituent rubber and steel cord, and several structural dimensions. The calculated wave length for a 165SR13 automobile tire with steel breakers (belts) was very close to experimental results. An additional study was then conducted on the post-buckling behavior of a laminated biased composite beam on an elastic foundation. This beam is subjected to axial compression. The calculated relationship between the buckled wave rise and the compressive membrane force also agreed well with experimental results.

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