Scale effects in orthotropic composite assemblies as micropolar continua: A comparison between weak-and strong-form finite element solutions

The aim of the present work was to investigate the mechanical behavior of orthotropic composites, such as masonry assemblies, subjected to localized loads described as micropolar materials. Micropolar models are known to be effective in modeling the actual behavior of microstructured solids in the presence of localized loads or geometrical discontinuities. This is due to the introduction of an additional degree of freedom (the micro-rotation) in the kinematic model, if compared to the classical continuum and the related strain and stress measures. In particular, it was shown in the literature that brick/block masonry can be satisfactorily modeled as a micropolar continuum, and here it is assumed as a reference orthotropic composite material. The in-plane elastic response of panels made of orthotropic arrangements of bricks of different sizes is analyzed herein. Numerical simulations are provided by comparing weak and strong finite element formulations. The scale effect is investigated, as well as the significant role played by the relative rotation, which is a peculiar strain measure of micropolar continua related to the non-symmetry of strain and work-conjugated stress. In particular, the anisotropic effects accounting for the micropolar moduli, related to the variation of microstructure internal sizes, are highlighted

Lmit and shakedown analysis based on solid shell models

The paper treats the formulation of the shakedown problem and, as special case, of the limit analysis problem, using solid shell models and ES-FEM discratization technology. In this proposal the Discrete shear gap method is applied to alleviate the shear locking phenomenon

Some remarks on the regularity of minimizers of integrals with anisotropic growth

summary:We prove higher integrability for minimizers of some integrals of the calculus of variations; such an improved integrability allows us to get existence of weak second derivatives

Uniform ellipticity and pp-qq growth

Fix any two numbers $p$ and $q$, with $1<p<q$; we give an example of an integral functional enjoying uniform ellipticity and $p$-$q$ growth

Existence of weak solutions for elliptic systems with p,q-growth

We consider a non-linear system of m equations in divergence form and a boundary condition: {Sigma(n)(i=1) partial derivative/partial derivative x(i) (A(i)(alpha)(x, Du(x))) = 0, 1 &lt;= alpha &lt;= m, in Omega u = (u) over tilde on partial derivative Omega. The functions A(i)(alpha)(x, z) are Holder continuous with respect to x and vertical bar z vertical bar(p) - c(1) &lt;= Sigma(m)(alpha=1) Sigma(n)(i=1) A(i)(alpha)(x, z)z(i)(alpha) &lt;= c(2)(1 + vertical bar z vertical bar)(q), 2 &lt;= p &lt;= q. We prove the existence of a weak solution u in ((u) over tilde + W-0(1,p)(Omega; R-m)) boolean AND W-loc(1,q)(Omega; R-m), provided p and q are close enough and under suitable sununability assumptions on the boundary datum (u) over tilde

EPUB Editor. Autoproduzione di e-book come esperienza didattica.

La sostanziale differenza tra book ed e-book è data dal fatto che nel libro cartaceo (book), il contenuto e il “dispositivo di lettura” sono integrati, mentre l’e-book distingue il contenuto (file) dal dispositivo utilizzato per fruirlo. Oltre a ciò, la tecnologia digitale consente di esplorare forme espressive del tutto inedite rispetto alla carta, che non sono date solo dalla multimedialità e interattività, ma anche da aspetti funzionali dei dispositivi digitali e dello “status” digitale del contenuto per molti versi non ancora del tutto attuati ed implementati. Il formato EPUB, meglio di altri, consente di applicare queste peculiarità ad un e-book e di svilupparlo in modo semplice ed immediato tramite uno degli strumenti autore disponibili sul mercato, quale, ad esempio, EPUB Editor, un tool online particolarmente utilizzato in contesto scolastico e didattico, di cui vengono dati esempi di lavori realizzati

Butterfly support for o diagonal coeficients and boundedness of solutions to quasilinear elliptic systems

We consider quasilinear elliptic systems in divergence form. In general,we cannot expect thatweak solutions are locally bounded because of De Giorgi’s counterexample. Here we assume that off-diagonal coeficients have a "butterfly support": this allows us to prove local boundedness of weak solutions.publishe

Limitatezza locale di minimi vettoriali di funzionali non convessi

We prove a local boundedness result for local minimizers of a class of non-convex functionals, under special structure assumptions on the energy density. The proof follows the lines of that in [CupLeoMas17], where a similar result is proved under slightly stronger assumptions on the energy density.Dimostriamo un risultato di limitatezza locale per minimi locali di una classe di funzionali non convessi, con particolari ipotesi di struttura sulla densità di energia. La dimostrazione procede come quella in [CupLeoMas17], dove un risultato simile è dimostrato con ipotesi leggermente più forti sulla densità di energia

Local boundedness of vectorial minimizers of non-convex functionals

We prove a local boundedness result for local minimizers of a class of non-convex functionals, under special structure assumptions on the energy density. The proof follows the lines of that in [CupLeoMas17], where a similar result is proved under slightly stronger assumptions on the energy density