Abstract

International Journal of Numerical Methods for Calculation and Design in Engineering (RIMNI) contributes to the spread of theoretical advances and practical applications of numerical methods in engineering and other applied sciences. RIMNI publishes articles written in Spanish, Portuguese and English. The scope of the journal includes mathematical and numerical models of engineering problems, development and application of numerical methods, advances in software, computer design innovations, educational aspects of numerical methods, etc. RIMNI is an essential source of information for scientifics and engineers in numerical methods theory and applications. RIMNI contributes to the interdisciplinar exchange and thus shortens the distance between theoretical developments and practical applications.

Desde 1985 la Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (RIMNI) contribuye a la difusión en castellano, portugués e inglés de los desarrollos teóricos y aplicaciones prácticas de los métodos numéricos, tanto en relación con su utilidad como instrumentos de cálculo y análisis para el ingeniero y el científico, como en aspectos que inciden en las nuevas tecnologías de diseño y proyecto de producción y procesos en ingeniería. La revista abarca áreas diversas, tales como: modelos matemáticos y numéricos de problemas de ingeniería, desarrollo y aplicaciones de los métodos numéricos, nuevos avances en temas de software, innovaciones en el campo del diseño por computador, aspectos didácticos de los métodos numéricos, etc. La revista constituye una fuente de información imprescindible para ingenieros y científicos sobre innumerables temas relacionados con los métodos numéricos y sus aplicaciones, contribuyendo a promover la transferencia de conocimiento interdisciplinar y, por consiguiente, a acortar la distancia que existe entre los desarrollos teóricos y las aplicaciones concretas.

Abstract

A new methodology for the geometrically nonlinear analysis of orthotropic membrane structures using triangular finite elements is presented. The approach is based on writing the constitutive equations in the principal fiber orientation of the material. A direct consequence of the fiber orientation strategy is the possibility to analyze initially out-of-plane prestressed membrane structures. An algorithm to model wrinkling behavior is also described. Examples of application to a number of membrane structures are presented.

Abstract

This paper summarizes the development for a large displacement formulation of a membrance composed of three-node triangular elements. A formulation in terms of the deformation gradient is first constructed in terms of nodal variables. In particular, the use of the right Cauchy-Green deformation tensor is shown to lead to a particulary simple representation in terms of nodal quantities. This may then be used to construct general models for use in static and transient analyses.

Abstract

This paper shows applications of a recently developed thin shell element adequate for the analysis of membrane and inflatable structures. The element is a three node triangle with only translational degrees of freedom that uses the configuration of the three adjacent elements to evaluate the strains in terms of the nodal displacements only. This allows to compute (constant) bending strains and (linear) membrane strains using a total Lagrangian formulation. Several examples, including inflation and deflation of membranes and some practical applications to the analysis, design and construction of membrane structures formed by low pressure inflatable tubes are presented.

Abstract

The computational challenge in dealing with membrane systems is closely connected to the lack of bending stiffness that constitutes the main feature of this category of structures. This manifests numerically in badly conditioned or singular systems requiring the use of stabilized solution procedures, in our case of a ‘pseudo‐dynamic’ approach. The absence of the flexural stiffness makes the membrane very prone to local instabilities which manifest physically in the formation of little ‘waves’ in ‘compressed’ areas. Current work presents an efficient, sub‐iteration free ‘explicit’, penalty material based, wrinkling simulation procedure suitable for the solution of ‘static’ problems. The procedure is stabilized by taking full advantage of the pseudo‐dynamic solution strategy, which allows to retain the elemental quadratic convergence properties inside the single solution step. Results are validated by comparison with published results and by setting up ‘numerical experiments’ based on the solution of test cases using dense meshes. Copyright © 2005 John Wiley & Sons, Ltd. 

Abstract

This paper shows applications of a recently developed thin shell element adequate for the analysis of membrane and inflatable structures. The element is a three node triangle with only translational degrees of freedom that uses the configuration of the three adjacent elements to evaluate the strains in terms of the nodal displacements only. This allows to compute (constant) bending strains and (linear) membrane strains using a total Lagrangian formulation. Several examples, including inflation and deflation of membranes and some practical applications to the analysis, design and construction of membrane structures formed by low pressure inflatable tubes are presented.