scholarly journals Impact of structural uncertainties on the buckling strength of cylindrical GLARE panels subjected to uniform compression

2021 ◽  
Vol 349 ◽  
pp. 01003
Author(s):  
Costas Kalfountzos ◽  
George Bikakis ◽  
Efstathios Theotokoglou
Keyword(s):  
Latin Hypercube Sampling ◽  
Buckling Load ◽  
Design System ◽  
Elastic Buckling ◽  
Random Input ◽  
Element Analysis ◽  
Uniform Compression ◽  
Deterministic Analysis ◽  
Buckling Strength ◽  
Input Variables

The objective of this article is the investigation of the elastic buckling strength of cylindrical simply supported GLARE (GLAss REinforced) panels subjected to axial compression using probabilistic analysis methods, so that the effect of uncertainties associated with material properties and dimensions of the panels on their elastic buckling load can be evaluated. The mechanical properties of aluminum along with the dimensions of aluminum and unidirectional (UD) glass-epoxy layers are considered to be random input variables whereas the critical buckling load is defined as a random output parameter. The employed eigenvalue buckling analysis and the probabilistic finite element analysis were carried out with ANSYS software. The Probabilistic Design System (PDS), along with the Monte Carlo Simulation and the Latin Hypercube Sampling method were used for the calculations. It is found that the thickness of aluminum layers has the strongest effect on the buckling strength, among the considered random input variables. It is also demonstrated that there is a considerable probability for the buckling load of GLARE panels to be overestimated when a deterministic analysis is conducted.

scholarly journals Global Sensitivity Analysis Of In-Plane Elastic Buckling Of Steel Arches

2020 ◽  
Vol 10 (6) ◽  
pp. 6476-6480
Author(s):  
Τ. Η. Nguyen
Keyword(s):  
Sensitivity Analysis ◽  
Monte Carlo Simulation ◽  
Material Properties ◽  
Global Sensitivity Analysis ◽  
Elastic Buckling ◽  
Random Input ◽  
Uniform Compression ◽  
Global Sensitivity ◽  
Industrial Structures ◽  
Input Variables

Steel arches are widely used in civil engineering and industrial structures. Their response depends on material properties, geometric dimensions, and boundary conditions. The objective of the current study is to perform global sensitivity analysis and to assess the influence of random input parameters on the in-plane elastic buckling of steel arches. The in-plane elastic buckling load of steel arches under uniform compression proposed in previous studies is adopted. The influence of the random input variables of the structure is evaluated using Sobol’s global sensitivity analysis. Monte Carlo simulation is also employed to rank the influence of input random variables.

scholarly journals Use of the correlation between input variables in estimating the risk of feedlot finishing of steers and young steers

2014 ◽  
Vol 86 (2) ◽  
pp. 945-954 ◽  
Author(s):  
PAULO S. PACHECO ◽  
JOÃO RESTLE ◽  
LEONIR L. PASCOAL ◽  
FABIANO N. VAZ ◽  
RICARDO Z. VAZ ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Stochastic Dominance ◽  
Net Present Value ◽  
Latin Hypercube Sampling ◽  
Risk Estimate ◽  
Present Value ◽  
Random Input ◽  
Financial Indicator ◽  
Input Variables ◽  
Diet Intake

The objective of this study was to evaluate the risk of feedlot finishing of steers (22.8 months) and young steers (15.2 months), using or not a correlation between the random input variables (data collected from 2004 to 2010) in the simulation of the Net Present Value (NPV) financial indicator. The animals were fed a diet containing roughage:concentrate ratio of 60:40 for 34 and 143 days, respectively, until they had reached a predetermined slaughter weight of 430 kg. For the NPV simulation, Latin Hypercube sampling was used, with 2000 interactions. The stochastic dominance analysis, test of differences between pairs of curves of cumulative distributions and sensitivity analysis were carried out. The NPV simulation using the correlation resulted in the best option for risk estimate. The confinement of young steers was the alternative of investment most viable than confinement of steers (NPV ≥ 0 of 80.4 vs. 62.3% in the simulation with correlation, respectively). Sensitivity analysis determined the following items had the greatest impact on the estimate of NPV: prices of fat and thin cattle, initial and final weights, diet costs, minimum rate of attractiveness and diet intake.

Estimation of Elastic Buckling Strength of a Non-Spherical Tank in the Partially Filled Condition

2017 ◽  
Author(s):  
Atsushi Sano ◽  
Naoya Matsubara ◽  
Naruyoshi Izumi ◽  
Masahiko Fujikubo
Keyword(s):  
Strength Analysis ◽  
Toroidal Shell ◽  
Elastic Buckling ◽  
Stress Distributions ◽  
Element Analysis ◽  
Initial Shape ◽  
Buckling Strength ◽  
Buckling Stress ◽  
Spherical Tank ◽  
Shell Finite Element

A method of estimating elastic buckling strength of a non-spherical tank intended for the use in LNG carriers is presented. Partially filled condition that causes combined meridional tension and circumferential compression is considered. Analytical expression of pre-buckling stress distributions is derived based on membrane shell theory. These stresses are applied to the elastic buckling strength analysis employing Hutchinson’s solution for a toroidal shell segment under similar stress condition. The buckling strength of a spherical shell is highly sensitive to initial shape imperfections, but these are not considered as a most fundamental case. The predicted stress distributions and elastic buckling strength are compared with those calculated by the 3D shell finite element analysis.

Long Wavelength Buckling of Cubic Open-Cell Foams Subjected to Uniaxial Compression

2007 ◽  
Vol 353-358 ◽  
pp. 583-586 ◽  
Author(s):  
Dai Okumura ◽  
Atsushi Okada ◽  
Nobutada Ohno
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Uniaxial Compression ◽  
Elastic Buckling ◽  
Element Analysis ◽  
Open Cell ◽  
Buckling Strength ◽  
Long Wavelength ◽  
Onset Condition ◽  
Open Cell Foams

In this study, the elastic buckling strength of cubic open-cell foams subjected to uniaxial compression is investigated using the homogenization framework developed by the present authors (Ohno et al., JMPS 2002; Okumura et al., JMPS 2004). First of all, based on the framework, the microscopic bifurcation and macroscopic instability of cubic open-cell foams are numerically analyzed by performing finite element analysis. It is thus shown that long wavelength buckling is the primary mode and occurs just after the onset of macroscopic instability. Then, a solution for predicting the stress of long wavelength buckling is analytically derived from the onset condition of macroscopic instability. The validity of this analytical solution is demonstrated by the finite element results.

Optimization of Air Plane Wing Rib Using Finite Element Analysis

2013 ◽  
Author(s):  
Naveen Prakash Goravi Vijaya Dev ◽  
Anoop Kumar Koduru Satish ◽  
Doddabasappa Veerapur
Keyword(s):  
Cross Section ◽  
Buckling Load ◽  
Optimum Thickness ◽  
Element Analysis ◽  
Buckling Strength ◽  
Compression Load ◽  
Simply Supported ◽  
Plate Shape ◽  
Circular Holes ◽  
Parametric Studies

Ribs are the stiffening members in the wing of air plane. Ribs usually have a thin flat plate shape accommodating cutouts, stiffeners and attachments. Most of the time there is a failure of rib due to critical buckling load even though the component is stressed well below the ultimate stress. Hence the rib is designed to carry maximum buckling load. The objective was to increase the critical buckling strength and reduce the weight of the rib. Linear static and buckling analysis were performed on the idealized configuration using FEM packages. Simply supported rectangular plate with different number of inline holes subjected to compression load was evaluated. The material considered was aluminum alloy. Various parametric studies were carried out to arrive at the optimum rib thickness and cross section. Once the optimum thickness of the plate was found out, reduction in the weight of the plate was done by providing various in line circular holes. From the study it was found that inserting circular hole in the plate enhances the buckling strength of the plate. The buckling strength of the plate was increased as the number of holes increased.

scholarly journals Assessment of the global stability of three-limbed steel tube latticed column using finite element modelling

2021 ◽  
Vol 2045 (1) ◽  
pp. 012021
Author(s):  
Y D Fu ◽  
X Y Dai ◽  
H D Zhang ◽  
K G Shang
Keyword(s):  
Finite Element ◽  
Global Stability ◽  
Steel Tube ◽  
Buckling Analysis ◽  
Buckling Load ◽  
Elastic Buckling ◽  
Analysis Method ◽  
Element Analysis ◽  
Stability Performance ◽  
Geometric Defect

Abstract In order to study the stability performance of the three-limbed steel tube latticed column, the finite element numerical analysis method based on the structural stability theory is adopted. Firstly, the linear analysis of the three-limbed steel tube latticed column without diagonal lacing bar is carried out, and the calculation method of elastic buckling load considering the influence of shear deformation is obtained. Then, the elastic buckling analysis and elastoplastic buckling analysis three-limbed steel tube latticed column with diagonal lacing bar are carried out. The elastic buckling load and elastoplastic buckling load of three-limbed steel tube latticed column with diagonal lacing bar are studied when only the global initial geometric defects, only the member initial geometric defects, and both kinds of defects are considered at the same time. The results show that the direct finite element analysis method can be used to calculate the elastic buckling load of three-limbed steel tube latticed column with diagonal lacing bar, and the error is 6.67%. In the elastic analysis of three-limbed steel tube latticed column with diagonal lacing bar, the column global stability mainly depends on the global initial geometric defects, and the member initial geometric defect is negligible. And when two kinds of defects are applied at the same time, the structural buckling load is reduced by less than 0.20% compared to the global initial geometric defects. In the elastoplastic analysis, the column global stability is determined by both the global initial geometric defect and the member initial geometric defect. When both defects are applied at the same time, the structural buckling load decreases by less than 0.65% compared to the global initial geometric defect only, and 7.60% compared to the member initial geometric defects only. It can be concluded that there is little difference in the overall stability bearing capacity between the two kinds of defects.

Buckling characteristics of cut-out borne composite stiffened hyperbolic paraboloid shell panel

2021 ◽  
pp. 146442072110058
Author(s):  
Sarmila Sahoo
Keyword(s):  
Finite Element ◽  
Orientation Angle ◽  
Buckling Load ◽  
Benchmark Problems ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Load Effect ◽  
Global Buckling ◽  
Fiber Orientation Angle ◽  
Shell Panel

The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.

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