The effect of material and thickness variability on the buckling load of shells with random initial imperfections

Papadopoulos, V; Papadrakakis, M

dc.contributor.author	Papadopoulos, V	en
dc.contributor.author	Papadrakakis, M	en
dc.date.accessioned	2014-03-01T01:23:10Z
dc.date.available	2014-03-01T01:23:10Z
dc.date.issued	2005	en
dc.identifier.issn	0045-7825	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16853
dc.subject	Autoregressive model	en
dc.subject	Evolutionary spectra	en
dc.subject	Non-linear shell finite element	en
dc.subject	Random imperfections	en
dc.subject	Spectral representation	en
dc.subject.classification	Engineering, Multidisciplinary	en
dc.subject.classification	Mathematics, Interdisciplinary Applications	en
dc.subject.classification	Mechanics	en
dc.subject.other	Buckling	en
dc.subject.other	Computer simulation	en
dc.subject.other	Elastic moduli	en
dc.subject.other	Elasticity	en
dc.subject.other	Elastoplasticity	en
dc.subject.other	Monte Carlo methods	en
dc.subject.other	Random processes	en
dc.subject.other	Regression analysis	en
dc.subject.other	Stiffness matrix	en
dc.subject.other	Structural loads	en
dc.subject.other	Thickness measurement	en
dc.subject.other	Buckling load	en
dc.subject.other	Power spectra	en
dc.subject.other	Spatial variability	en
dc.subject.other	Stochastic fields	en
dc.subject.other	Shells (structures)	en
dc.subject.other	buckling	en
dc.subject.other	mathematical method	en
dc.subject.other	mechanical engineering	en
dc.title	The effect of material and thickness variability on the buckling load of shells with random initial imperfections	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.cma.2004.01.043	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.cma.2004.01.043	en
heal.language	English	en
heal.publicationDate	2005	en
heal.abstract	The effect of material and thickness imperfections on the buckling load of isotropic shells is investigated in this paper. For this purpose, the concept of an initial 'imperfect' structure is introduced involving not only geometric deviations of the shell structure from its perfect geometry but also a spatial variability of the modulus of elasticity as well as the thickness of the shell. The initial geometric imperfections are described as a two-dimensional uni-variate (2D-1V) stochastic field with statistical properties that are either based on an available data bank of measured initial imperfections or assumed, in cases where no experimental data is available. In order to describe the non-homogeneous characteristics of the initial imperfections, the spectral representation method is used in conjunction with an autoregressive moving average model with evolutionary power spectra based on a statistical analysis of the experimentally measured imperfections. In cases where no experimental results is available, the initial imperfections are assumed to be homogeneous and their impact on the buckling load is investigated on the basis of 'worst'-case scenarios with respect to the correlation length parameters of the stochastic fields. The elastic modulus and the shell thickness are described as 2D-1V non-correlated homogeneous stochastic fields, while the stochastic stiffness matrix of the shell elements is formulated using the local average method. The Monte Carlo Simulation method is used to calculate the variability of the buckling load. while for the determination of the limit load of the shell, a stochastic formulation of the elastoplastic, and geometrically non-linear TRIC facet triangular shell element is implemented. (C) 2004 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE SA	en
heal.journalName	Computer Methods in Applied Mechanics and Engineering	en
dc.identifier.doi	10.1016/j.cma.2004.01.043	en
dc.identifier.isi	ISI:000227483200007	en
dc.identifier.volume	194	en
dc.identifier.issue	12-16	en
dc.identifier.spage	1405	en
dc.identifier.epage	1426	en