0000000000137924
AUTHOR
Teotista Panzeca
How to use the SBEM in the practical engineering?
Strain gradient elasticity within the SGBEM
Metodi innovativi di analisi su archi e volte
Interaction problems between in-plane and out-plane plates by SBEM
Computational aspects in thermoelasticity by the symmetric boundary element method
A combined approach of SGBEM and conic quadratic optimization for limit analysis
The static approach to evaluate the limit multiplier directly was rephrased using the Symmetric Galerkin Boundary Element Method (SGBEM) for multidomain type problems [1,2]. The present formulation couples SGBEM multidomain procedure with nonlinear optimization techniques, making use of the self-equilibrium stress equation [3-5]. This equation connects the stresses at the Gauss points of each substructure (bem-e) to plastic strains through a self-stress matrix computed in all the bem-elements of the discretized system. The analysis was performed by means of a conic quadratic optimization problem, in terms of discrete variables, and implemented using Karnak.sGbem code [6] coupled with MathLa…
Piastra di Kirchhoff con l'impiego del metodo simmetrico degli elementi di contorno
Modellazione lineare delle grandezze di contorno nell'analisi per sottostrutture delle piastre inflesse via SBEM
Strutture in muratura: le catene nel consolidamento
Impiego dei sottodomini via SBEM nell’analisi delle murature
Error reduction strategy in the analysis via SGBEM
A multidomain SGBEM approach for shakedown analysis as a conic quadratic optimization problem
L'evoluzione della frattura nei materiali fragili non coesivi con l'impiego del metodo simmetrico degli elementi di contorno
MACRO-ZONES SGBEM APPROACH FOR STATIC SHAKEDOWN ANALYSIS AS CONVEX OPTIMIZATION
A new strategy utilizing the Multidomain SGBEM for rapidly performing shakedown analysis as a convex optimization problem has been shown in this paper. The present multidomain approach, called displacement method, makes it possible to consider step-wise physically and geometrically nonhomogeneous materials and to obtain a self-equilibrium stress equation regarding all the bem-elements of the structure. Since this equation includes influence coefficients, which characterize the input of the quadratic constraints, it provides a nonlinear optimization problem solved as a convex optimization problem. Furthermore, the strategy makes it possible to introduce a domain discretization exclusively of…
On the computational aspects of a symmetric multidomain BEM for elastoplastic analysis
The symmetric boundary element method (SBEM) is applied to the elasto-plastic analysis of bodies subdivided into substructures. This methodology is based on the use of: a multidomain SBEMapproach, for the evaluation of the elastic predictor; a return mapping algorithm based on the extremal paths theory, for the evaluation of inelastic quantities characterizing the plastic behaviour of each substructure; and a transformation of the domain inelastic integrals of each substructure into corresponding boundary integrals. The elastic analysis is performed by using the SBEM displacement approach, which has the advantage of creating system equations that only consist of nodal kinematical unknowns a…
Multidomain approach for thermoelasticity in the SBEM
Incremental elastoplastic analysis for active macro-zones
In this paper a strategy to perform incremental elastoplastic analysis using the symmetric Galerkin boundary element method for multidomain type problems is shown. The discretization of the body is performed through substructures, distinguishing the bem-elements characterizing the so-called active macro-zones, where the plastic consistency condition may be violated, and the macro-elements having elastic behaviour only. Incremental analysis uses the well-known concept of self-equilibrium stress field here shown in a discrete form through the introduction of the influence matrix (self-stress matrix). The nonlinear analysis does not use updating of the elastic response inside each plastic loop…
Frictionless contact-detachment problem between elastic bodies using symmetric BEM
A multidomain approach of the SBEM in the plate bending analysis
The aim of this paper is to apply the multidomain approach of the SBEM to the plate bending analysis. The plate is subdivided into macro-elements connected each other along the interface boundary. Every macro-element is defined by an elastic relation which connects the generalized shear force and moments at the interface to the nodal displacements and rotations of the same boundary and to the loads. This approach allows a considerable reduction of the variables through a condensation process which leaves the interface kinematical unknowns, only. The assembly process may be obtained through the regularity conditions prescribed at the interface.
Problemi di contatto nel sistema suolo-struttura
Frictionless unilateral contact by Symmetric Boundary Element Method
Sicurezza delle pareti murarie soggette a forze fuori dal piano.
La propagazione della frattura fragile nell'ambito della formulazione simmetrica del BEM
Multidomain Symmetric Galerkin BEM for non-linear analysis of masonries in-plane loaded
The preservation of the historical and monumental buildings, but also of the considerable heritage of old constructions made by traditional techniques, is one of the actual problems of the structural mechanics. The level of knowledge of their structural behavior in presence of external actions is made through calculus methods and simple procedures in order to allow a reading of the material suffering degree and as a consequence of the related safety. In this paper an elastic analysis of walls, also in presence of geometrical nonlinearity consisting in the contact/detachment phenomenon among stone blocks. The wall having any shape and zone-wise variable physical characteristics is loaded in …
Ottimizzazione della discretizzazione del contorno basata sulla energia residua nell'ambito del MEC simmetrico
Strain energy evaluation in structures having zone-wise physical-mechanical quantities
Elastoplastic analysis by the multidomain Symmetric Boundary Element Method
Tecniche di trasformazione di integrali di dominio in integrali di contorno nell'ambito del SBEM
La formulazione simmetrica alla Galerkin del BEM in elastoplasticità
SBEM macro-element with sides constrained by springs
Analisi strutturale condotta con il BEM simmetrico in analogia al FEM
Nell’articolo si presenta l’approccio agli spostamenti del Metodo Simmetrico degli Elementi di Contorno attraverso una suddivisione del corpo continuo in macroelementi denominati ebem. Attraverso questo approccio, caratterizzato da una forte condensazione delle variabili, si determina per ogni e-bem una matrice capostipite a partire dalla quale viene generata la relazione costitutiva del singolo e-bem. Quest’ultima relaziona soltanto variabili all’interfaccia tra i macroelementi, e precisamente il vettore delle trazioni pesate con il vettore degli spostamenti nodali e con il vettore delle azioni esterne. Una tale strategia è molto simile a quella seguita dal Metodo degli Elementi Finiti, ma…
Multidomain SBEM analysis for two dimensionalelastoplastic-contact problems
The Symmetric Boundary Element Method based on the Galerkin hypotheses has found application in the nonlinear analysis of plasticity and contact-detachment problems, but dealt with separately. In this paper we wants to treat these complex phenomena together. This method works in structures by introducing a subdivision into sub-structures, distinguished into macroelements, where elastic behaviour is assumed, and bem-elements, where it is possible for plastic strains to occur. In all the sub-structures, elasticity equations are written and regularity conditions in weighted (weak) form and/or in nodal (strong) form between boundaries have to be introduced, to attain the solving equation system.
Elastoplastic analysis for active macro-zones via multidomain symmetric Galerkin BEM
In this paper a strategy to perform elastoplastic analysis by using the Symmetric Boundary Element Method (SBEM) for multidomain type problems is shown. This formulation uses a self-stresses equation to evaluate the trial stress in the predictor phase, and to provide the elastoplastic solution in the corrector one. Since the solution is obtained through a return mapping involving simultaneously all the plastically active bem-elements, the proposed strategy does not depend on the path of the plastic strain process and it is characterized by computational advantages due the considerable decrease of the plastic iterations number. This procedure has been developed inside Karnak.sGbem code [1] b…