Comparative Study of Post-Buckling Load Redistribution in Stiffened Aircraft Panel With and Without Material Nonlinearity

2018 ◽  
Author(s):  
Enes Aydin ◽  
Altan Kayran
Keyword(s):  
Finite Element ◽  
Material Nonlinearity ◽  
Stiffened Panel ◽  
Effective Width ◽  
Element Analysis ◽  
Buckling Behavior ◽  
The Finite Element Analysis ◽  
Post Buckling ◽  
Buckling Coefficient ◽  
Clamped Edge

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.

scholarly journals AEROSPACE STIFFENED PANEL INITIAL SIZING WITH NOVEL SKIN SUB-STIFFENING FEATURES

2012 ◽  
Vol 12 (05) ◽  
pp. 1250060 ◽  
Author(s):  
D. QUINN ◽  
A. MURPHY ◽  
C. GLAZEBROOK
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Crack ◽  
Local Stability ◽  
Static Strength ◽  
Stiffened Panel ◽  
Element Analysis ◽  
Stiffened Panels ◽  
Buckling Behavior ◽  
Buckling Coefficient

The introduction of skin sub-stiffening features has the potential to modify the local stability and fatigue crack growth performance of stiffened panels. Proposed herein is a method to enable initial static strength sizing of panels with such skin sub-stiffening features. The method uses bespoke skin buckling coefficients, automatically generated by Finite Element analysis and thus limits the modification to the conventional aerospace panel initial sizing process. The approach is demonstrated herein and validated for prismatic sub-stiffening features. Moreover, examination of the generated buckling coefficient data illustrates the influence of skin sub-stiffening on buckling behavior, with static strength increases typically corresponding to a reduction in the number of initial skin longitudinal buckle half-waves.

Wrinkling of Thin Membrane Under Thermal Loading

2006 ◽  
Author(s):  
Jia Gao ◽  
Seungbae Park ◽  
James Pitarresi ◽  
Dorel Homentcovschi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Stress ◽  
Critical Value ◽  
Thin Membrane ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Post Buckling ◽  
Formation And Evolution ◽  
Wrinkle Generation

There has been an increasing interest in the applications of thin membrane in space application, flexible electronic display, manufacturing of glass displays and growth of film on materials at elevated temperatures. Because of the negligible bending stiffness of thin membranes, membranes are lack of resistance to compressive stress. For the applications at high temperatures, the thermal expansion coefficient mismatch between membrane and substrate materials may generate compressive stress that causes the membrane buckling. The study of thermal buckling of isotropic elastic plate in the context of the large - deflection theory was the subject of a series of papers[1-5]. However, it has been noted that none of these papers has considered the second buckling of the membrane resulting in membrane wrinkling. The presence of wrinkles may significantly change deflection and stress profile of membranes. So, it is important to develop an effective analysis method to investigate the wrinkle formation and evolution in membrane subjected the elevated temperature. This paper presents the experiment work to investigate wrinkle formation and evolution in membranes heated from room temperature up to 170 °C. The specimens consist of polymer and metal membranes with steel and silicon substrate respectively. A wide range of membrane shapes and aspect ratios are considered in this work. An experiment set up is developed to study the deflection profiles of membranes at discrete temperatures. The information gained from this experiment work is used to validate numerical modeling results. The Finite Element Analysis results using nonlinear post-buckling analysis are also included in this paper. The nonlinear post-buckling analysis provides a good understanding of the mechanism of wrinkle generation and evolution as temperature increased. It is shown that the first buckling of membrane significantly reduces bending stiffness thus to create localized buckling modes accounting for the wrinkle generation. The wrinkle pattern is stable until the temperature reaches the next critical value. After this critical temperature, the wrinkle pattern is changed until temperature reaches the next critical value. The new wrinkle pattern is keeping evolved until the final temperature is reached. The finite element analysis results are in good agreement with experimental observations.

Buckling Behavior of General Dome Ends under External Pressure, Using Finite Element Analysis

2011 ◽  
Vol 471-472 ◽  
pp. 833-838 ◽  
Author(s):  
Behzad Abdi ◽  
Hamid Mozafari ◽  
Ayob Amran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Major Axis ◽  
External Pressure ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Buckling Behavior ◽  
Ellipse Method ◽  
The Finite Element Analysis ◽  
Critical Buckling Pressure

In this paper, the finite element analysis is used to investigate the effect of shape of dome ends on the buckling of pressure vessel heads under external pressure. The Finite Element Analysis (FEA) with the use of elastic buckling analysis was applied to predict the critical buckling pressure. The influence of geometrical parameters such as thickness, knuckle radius, and the ratio of minor axis to the major axis of dome ends, on the weight and the critical buckling pressure of hemispherical, ellipsoidal, and torispherical dome ends, was studied. The four-centered ellipse method was used to describe the geometry of the dome end.

The Finite Element Analysis on Shear-Lag Effect of the Steel Box-Girder

2013 ◽  
Vol 671-674 ◽  
pp. 815-819
Author(s):  
Yi Sheng Li ◽  
Jun Ping Wang ◽  
Wei Liu ◽  
Jian Ming Shen
Keyword(s):  
Finite Element ◽  
Effective Width ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Element Analysis ◽  
Box Girder ◽  
Finite Element Software ◽  
Steel Box Girder ◽  
Lag Effect ◽  
The Finite Element Analysis

The shear-lag effect of steel box-girder is qualitatively analyzed by using the finite element software ANSYS. Various methods to reduce the shear-lag effect are studied, and the most effective method is changing the web layout and increasing the number of box-room among them. The suggested value of effective width to thickness ratio b1/t1 of the flange without considering the shear-lag effect are obtained in this paper.

The Finite Element Analysis of Ultimate Bearing Capacity of Initial Bending on the T-Axis Compression Component

2013 ◽  
Vol 690-693 ◽  
pp. 1914-1918
Author(s):  
Yang Yang Han ◽  
Cai Xia Zhang ◽  
Ya Qin Li ◽  
Si Yu Chen ◽  
Chun Shan Liu
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Cross Section ◽  
Element Calculation ◽  
Element Analysis ◽  
Cross Sectional ◽  
Buckling Behavior ◽  
The Finite Element Analysis ◽  
Axis Compression ◽  
The Stability

There is little research about the stability of T-stub steel axial compression component at home and abroad, and it remains to further investigation. On the basis of taking initial bending and other factors into consideration, through theoretical analysis and finite element calculation, this paper studies the T-stub steel axial compression buckling behavior and carrying capacity mainly using three different cross-section and different lengths ZC cross-sectional specimens.

The Ultimate Strength of Stiffened Panel with Overall Buckling

2011 ◽  
Vol 308-310 ◽  
pp. 1297-1301
Author(s):  
Bao Zhang ◽  
Qin Sun
Keyword(s):  
Ultimate Strength ◽  
Orthotropic Plate ◽  
Plate Theory ◽  
Stiffened Panel ◽  
Buckling Mode ◽  
Element Analysis ◽  
Buckling Behavior ◽  
Eigenvalue Method ◽  
Post Buckling ◽  
Overall Buckling

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.

Finite Element Analysis of Pressurized Fabric Beams With Material Nonlinearity

2006 ◽  
Author(s):  
Hui Zhang ◽  
William G. Davids ◽  
Michael L. Peterson ◽  
Adam Turner ◽  
Christopher Malm
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Virtual Work ◽  
Material Nonlinearity ◽  
Woven Fabric ◽  
Nonlinear Material ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Bend Tests ◽  
Point Bend

This paper presents a finite element analysis of inflated fabric beams that considers nonlinear material response and shear deformations. Applying the principle of virtual work, we obtain the FEM formulation for inflated fabric beams with material nonlinearity. Comparisons between 4-point bend tests of inflated woven fabric beams and finite element results indicate that the finite element analysis provides good estimates of deflections, and that it is important to incorporate the effects of shear deformation and pressure when predicting inflated fabric beam response.

scholarly journals Experimental Study and Effective Width Method for Cold-Formed Steel Lipped Channel Stud Columns with Holes

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yanli Guo ◽  
Xingyou Yao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ultimate Strength ◽  
Local Buckling ◽  
Effective Width ◽  
Element Analysis ◽  
Large Hole ◽  
The Finite Element Analysis ◽  
Cold Formed Steel ◽  
The Web

The objective of this paper is to investigate the buckling behavior and to present the design method of the ultimate strength in the basic effective width method (EWM) for cold-formed steel (CFS) lipped channel stud columns with holes in the web. 28 column tests were conducted under axial compression on the CFS lipped channel stud columns with circular and rectangular holes in different dimensions of cross sections and holes. The tested stud columns included 4 members without holes, 12 members with circular holes, and 12 members with rectangular holes. The test results showed that the stud columns with holes were governed by local buckling or the interaction of local buckling and distortional buckling. Compared with the stud columns without holes, the small hole had a slight influence on the ultimate strength of the tested specimens, and the large hole had a great effect on the ultimate strength of the tested specimens. The load capacities of the specimens decreased with the increase of the dimension of holes. Then, the finite element analysis was carried out to simulate the tested stud columns. The finite element analysis results showed good agreement with the experimental results about buckling modes and ultimate strengths, which indicated that it is feasible to analyze this kind of stud columns with holes by using the finite element method (FEM). Finally, the proposed effective width method was used to predict the ultimate strengths of stud columns with holes based on the proposed buckling coefficient formulas of the plate with holes. The comparison between calculated results and test and finite element results indicated that the proposed EWM is feasible and accurate to predict the ultimate strength of the CFS lipped channel stud columns with holes in the web.

Sign in / Sign up

Export Citation Format

Share Document