• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.599-610
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• 2007

In this paper, we described a co-rotational formulation for the geometrical nonlinear analysis of three-dimensional frames. We suggested a new concept called the Zero-Twist-Section Condition (ZTSC) to decide the element coordinate system consistently. According to the ZTSC procedure, it is possible to obtain an element coordinate system and natural deformations consistently when finite displacements and rotations are induced in an element. Based on the developed procedure, numerical examples are investigated to calculate natural rotations while finite displacements are imposed on an element. Also, the developed co-rotational procedure gives accurate results in the analysis of post-buckling problems with finite rotations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.381-386
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• 2007

The present study is concerned with the application of Constant arc-length method that proposed by Crisfield in the investigation of the geometrically nonlinear behaviour of spatial structures composed by truss or beam element. The arc-length method can trace the full nonlinear equilibrium path of Spatial structure far beyond the critical point such as limit or bifurcation point. So, we have developed the constant arc-length method of Crisfield to analysis spatial structure. The finite element formulation is used to develop the 3d truss/beam element including the geometrical nonlinear effect. In an effort to evaluate the merits of the methods, extensive numerical studies were carried out on a number of selected structural systems. The advantages of Constant arc length method in tracing the post-buckling behavior of spatial structures, are demonstrated.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.410-413
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• 2005

The results of an experimental and analytical study of composite pressure hull on buckling pressure are presented for LRN 300. Composite tensile test was done to know the composite material properties applied FE analysis for URN composite. We predicted the buckling and post buckling analysis of composite laminated cylindrical panels under external compression by using ABAQUS /Standard[Ver 6.4]. To obtain nonlinear static equilibrium solutions for unstable problems, where the load-displacement response can exhibit the type of nonlinear buckling behavior, during periods of the response, the load and/or the displacement may decrease as the solution evolves, used the modified Riks method. The modified Riks method is an algorithm that allows effective solution of such cases [7]. Experiments were conducted to verify the validation of present analysis for cross-ply laminated shells. The shells considered in the study have two different lamination patterns, $[{\pm}45/0/90]_{18s\;and}\;[/0/90]_{18s}$. Cylindrical panel of experiment and analysis have the radius of 200mm, length of 210mm and 60 degree of cutting angle. The critical load from experiment is $69\%$ of that of numerical analysis, because the fracture of matrix was generated before buckling. So URN 300 is not proper to use at the condition under high external pressue.

• Structural Engineering and Mechanics
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• v.6 no.7
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• pp.785-800
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• 1998

This paper deals with the nonlinear finite element analysis of fibre-reinforced plastic poles. Based on the principle of stationary potential energy and Novozhilov's derivations of nonlinear strains, the formulations for the geometric nonlinear analysis of general shells are derived. The formulations are applied to the fibre-reinforced plastic poles which are treated as conical shells. A semi-analytical finite element model based on the theory of shell of revolution is developed. Several aspects of the implementation of the geometric nonlinear analysis are discussed. Examples are presented to show the applicability of the nonlinear analysis to the post-buckling and large deformation of fibre-reinforced plastic poles.

• Advances in aircraft and spacecraft science
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• v.8 no.4
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• pp.345-372
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• 2021

The analysis of nonlinear vibrations, buckling, post-buckling, flutter boundary determination and post-flutter behavior of a homogeneous curved plate assuming cylindrical bending is conducted in this article. Other assumptions include simply-supported boundary conditions, supersonic aerodynamic flow at the top of the plate, constant pressure conditions below the plate, non-viscous flow model (using first- and third-order piston theory), nonlinear structural model with large deformations, and application of mechanical and thermal loads on the curved plate. The analysis is performed with constant environmental indicators (flow density, heat, Reynolds number and Mach number). The material properties (i.e., coefficient of thermal expansion and modulus of elasticity) are temperature-dependent. The equations are derived using the principle of virtual displacement. Furthermore, based on the definitions of virtual work, the potential and kinetic energy of the final relations in the integral form, and the governing nonlinear differential equations are obtained after fractional integration. This problem is solved using two approaches. The frequency analysis and flutter are studied in the first approach by transferring the handle of ordinary differential equations to the state space, calculating the system Jacobin matrix and analyzing the eigenvalue to determine the instability conditions. The second approach discusses the nonlinear frequency analysis and nonlinear flutter using the semi-analytical solution of governing differential equations based on the weighted residual method. The partial differential equations are converted to ordinary differential equations, after which they are solved based on the Runge-Kutta fourth- and fifth-order methods. The comparison between the results of frequency and flutter analysis of curved plate is linearly and nonlinearly performed for the first time. The results show that the plate curvature has a profound impact on the instability boundary of the plate under supersonic aerodynamic loading. The flutter boundary decreases with growing thermal load and increases with growing curvature.

• Steel and Composite Structures
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• v.46 no.4
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• pp.513-523
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• 2023

Buckling and post-buckling behaviors of geometrically perfect double-curvature shells made from smart composites have been investigated. The shell has been supposed to be exposed to transverse mechanical loading and magneto-electro-elastic (MEE) coupling. The composite shell has been made of two constituents which are piezoelectric and magnetic ingredients. Thus, the elastic properties might be variable based upon the percentages of the constituents. Incorporating small scale impacts in regard to nonlocal theory leads to the establishment of the governing equations for the double-curvature nanoshell. Such nanoshell stability will be shown to be affected by composite ingredients. More focus has been paid to the effects of small scale factor, electric voltage and magnetic intensity on stability curves of the nanoshell.

• Structural Engineering and Mechanics
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• v.15 no.2
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• pp.225-238
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• 2003

In the present study, the finite strip analysis of a box girder to simulate a ship's hull model is carried out to investigate its inelastic post-buckling behavior and to predict its ultimate flexural strength. Residual stresses and initial geometrical imperfections are both considered in the combined material and geometrical nonlinear analysis. The von-Mises yield criterion and the Prandtl-Reuss flow theory of plasticity are applied in modeling the elasto-plastic behavior of material. The Newton-Raphson iterative process is also employed in the analysis to achieve convergence. The numerical results agree well with the experimental data. The effects of some material and geometrical parameters on the ultimate strength of the structure are also investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.865-873
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• 2013

In this paper, numerical methods for wrinkle prediction of thin membrane were studied by finite element analysis. Techniques using membrane and shell elements were applied for triangular membrane. In case of membrane element method, the wrinkling was accounted for by the wrinkle algorithm of property modification, which was implemented to ABAQUS as a user subroutine. In case of shell method, geometrically nonlinear post-buckling analysis was performed to obtain the wrinkle deformation explicitly. The wrinkling deformation was induced by seeding the mesh with a random geometric imperfection. The results were investigated focusing on the mesh convergence and the solution accuracy.

• Computational Structural Engineering
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• v.9 no.3
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• pp.209-216
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• 1996

The primary objective of this paper is to grasp many characteristics of buckling behavior of latticed spherical domes under various conditions. The Arc-Length Method proposed by E.Riks is used for the computation and evaluation of geometrically nonlinear fundamental equilibrium paths and bifurcation points. And the direction of the path after the bifurcation point is decided by means of Hosono's concept. Three different nonlinear stiffness matrices of the Slope-Deflection Method are derived for the system with rigid nodes and results of the numerical analysis are examined in regard to geometrical parameters such as slenderness ratio, half-open angle, boundary conditions, and various loading types. But in case of analytical model 2 (rigid node), the post-buckling path could not be surveyed because of Newton-Raphson iteration process being diversed on the critical point since many eigenvalues become zero simultaneously.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.107-112
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• 2008

This paper investigates the variation of post-buckling behaviours of 2-dimensional shallow arch type truss after sizing optimization. The mathematical programming technique is used to produce the optimum member size of 2D arch truss against a central point load. Total weight of structure is considered as the objective function to be minimized and the displacement occurred at loading point and member stresses of truss are used as the constraint functions. The finite difference method is used to calculate the design sensitivity of objective function with respect to design variables. The postbuckling analysis carried out by using the geometrically nonlinear finite element analysis code ISADO-GN. It is found to be that there is a huge change of post-buckling behaviour between the initial structure and optimum structure. Numerical results can be used as useful information for future research of large spatial structures.