Post-Buckling Analysis of Stiffened Laminated Panel

1988 ◽  
Vol 55 (3) ◽  
pp. 635-640 ◽  
Author(s):  
Izhak Sheinman ◽  
Yeoshua Frostig

An analytical-numerical procedure is applied to investigate the post-buckling behavior of a composite laminated stiffened panel. The panel is modeled by plate elements for which the nonlinear equations are derived (via a variational principle) in terms of the lateral displacement and Airy stress function, and treated by resolving the variables into eigenfunctions in conjunction with a finite-difference scheme.

2016 ◽  
Vol 08 (03) ◽  
pp. 1650028
Author(s):  
Youhong Sun ◽  
Baisheng Wu ◽  
Yongping Yu

This paper is concerned with thermal post-buckling of uniform isotropic beams with axially immovable spring-hinged ends. The ends of the beam with elastic rotational restraints represent the actual practical support conditions and the classical hinged and clamped conditions can be achieved as the limiting cases of the rotational spring stiffness. The governing differential–integral equation is solved by assuming suitable admissible function for lateral displacement and by employing the Galerkin method. A brief and explicit analytical approximate formulation is established to predict the thermal post-buckling behavior of the beam. The present analytical approximate expressions show excellent agreement with the corresponding numerical solutions based on the shooting method. This confirms the effectiveness and verifies the accuracy of the formulas established.


1987 ◽  
Vol 54 (3) ◽  
pp. 558-562 ◽  
Author(s):  
I. Sheinman ◽  
M. Adan

A geometrical nonlinear theory of composite laminated beams is derived with the effect of transverse shear deformation taken into account. The theory is based on a high-order kinematic model, with the nonlinear differential equations solved by Newton’s method and a special finite-difference scheme. A parametric study of the shear effect involving several kinematic approaches was carried out for isotropic and anisotropic beams.


Author(s):  
Enes Aydin ◽  
Altan Kayran

In this article, a comparative study is presented on the post-buckling load redistribution in stiffened aircraft panels modeled with and without material nonlinearity. In the first part of the study, a baseline stiffened panel is generated for further investigation of the material nonlinearity on the post-buckling behavior and on the effective width of the stiffened panel. In this respect, a stiffener section which provides classical clamped edge condition is designed by matching the compression buckling coefficient determined by the finite element analysis closely with the analytically determined buckling coefficient of the clamped edge panel. Post-buckling analysis of the stiffened panel is then performed utilizing linear and nonlinear material models in the finite element analysis and the effect of material plasticity on the post-buckling behavior of the panel is ascertained. The load distribution in the stiffened panel is investigated just before the buckling of the panel and before the collapse of the panel in the post-buckled stage. The effective widths of the panel are calculated before the collapse of the panel using the load distributions determined by the finite element analyses of the panel models with and without material nonlinearity and comparisons are made with the effective width calculated by the classical effective width formulation. It is shown that material nonlinearity accounts for higher effective width and in general the classical empirical approach gives the smallest effective width.


2011 ◽  
Vol 308-310 ◽  
pp. 1297-1301
Author(s):  
Bao Zhang ◽  
Qin Sun

The post-buckling behavior of a stiffened panel is investigated in this paper. Firstly, the buckling mode of the stiffened panel is obtained using the linear buckling eigenvalue method. Then, the collapsing strength of the stiffened panel is calculated using the ultimate strength method based on large deflection orthotropic plate theory. In addition, nonlinear finite element analysis is performed to predict the post-buckling behavior of the stiffened panel. By comparing the model prediction and the analytical results of ultimate strength, it is shown that good accuracy can be achieved, especially for the method referring to membrane stress in mid-thickness of equivalent orthotropic plate. It suggests that the proposed method can predict the ultimate strength of whole stiffened panel accurately and effectively.


1993 ◽  
Vol 46 (11S) ◽  
pp. S148-S155 ◽  
Author(s):  
M. A. Souza

The paper discusses the influence that changes of the simply supported boundary condition during the loading process have on the dynamic post-buckling behavior of elastic thin-walled structures. Of special interest is the knife-edge type of support which is associated to the free-to-rotate boundary condition. The results presented show how changes of the free-to-rotate condition during the loading process can dramatically alter the response of thin-walled structures. This fact is highlighted by the equilibrium paths and the characteristic curves presented. The former relate the applied compressive load and the lateral displacement, whereas, the latter relate the compressive load and the square of the corresponding natural frequency of vibration. The importance of an adquate design of the supports is stressed in view of the observed dramatic changes. The work is done in the scope of the elastic stability and damping is not included in the analysis.


2016 ◽  
Vol 828 ◽  
pp. 99-116 ◽  
Author(s):  
Vincenzo Oliveri ◽  
Andrea Alaimo ◽  
Alberto Milazzo

A Rayleigh-Ritz approach for the analysis of buckling and post-buckling behavior of cracked composite stiffened plates is presented. The structure is modeled as the assembly of plate elements modeled by the first order shear deformation theory and taking geometric nonlinearities into account through the von Karman’s theory assumptions. Continuity along the plate elements connected edges and the enforcement of rigid and elastic restraints of the plate boundaries are obtained by using penalty techniques, which also allow to straightforwardly implement efficient crack modeling strategies. General symmetric and unsymmetric stacking sequences are considered and numerical procedures have been developed and used to validate the present solution by comparison with FEA results. Original results are presented for post-buckling solution of multilayered stiffened plates with through-the-thickness cracks, showing the effects of large displacements on the cracked plate post-buckling behavior.


1983 ◽  
Vol 11 (1) ◽  
pp. 3-19
Author(s):  
T. Akasaka ◽  
S. Yamazaki ◽  
K. Asano

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.


2021 ◽  
Vol 15 ◽  
pp. 174830262110113
Author(s):  
Qianying Hong ◽  
Ming-jun Lai ◽  
Jingyue Wang

We present a convergence analysis for a finite difference scheme for the time dependent partial different equation called gradient flow associated with the Rudin-Osher-Fetami model. We devise an iterative algorithm to compute the solution of the finite difference scheme and prove the convergence of the iterative algorithm. Finally computational experiments are shown to demonstrate the convergence of the finite difference scheme.


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