Polytechnic University of Milan

About: Polytechnic University of Milan is a education organization based out in Milan, Italy. It is known for research contribution in the topics: Finite element method & Population. The organization has 18231 authors who have published 58416 publications receiving 1229711 citations. The organization is also known as: PoliMi & L-NESS.

Structural Assessment of Corroded Reinforced Concrete Beams: Modeling Guidelines

Abstract: The evolution of the structural behavior in reinforced concrete beams subjected to reinforcement corrosion is studied here, by developing a suitable numerical procedure, which is validated by comparison with available test data. There are two objectives of this study: The understanding of the many aspects of the progressive damage in an existing structure (cracking and crushing, bar yielding, bond failure), and the assessment of the actual safety level. Nonlinear finite element analysis is used; the effects of corrosion are modeled by reducing the geometry of the finite elements representing separately the steel bars and the concrete, and by modifying the constitutive laws of the materials (steel and concrete) and of their interface (bond). Both the service and ultimate limit states are studied, showing the importance of the following phenomena: (1) Stiffness decay because of impaired tension stiffening, (2) crack pattern evolution accompanied by enhanced shear effects, (3) strength deterioration in bendi...

First GOCE gravity field models derived by three different approaches

Abstract: Three gravity field models, parameterized in terms of spherical harmonic coefficients, have been computed from 71 days of GOCE (Gravity field and steady-state Ocean Circulation Explorer) orbit and gradiometer data by applying independent gravity field processing methods. These gravity models are one major output of the European Space Agency (ESA) project GOCE High-level Processing Facility (HPF). The processing philosophies and architectures of these three complementary methods are presented and discussed, emphasizing the specific features of the three approaches. The resulting GOCE gravity field models, representing the first models containing the novel measurement type of gravity gradiometry ever computed, are analysed and assessed in detail. Together with the coefficient estimates, full variance-covariance matrices provide error information about the coefficient solutions. A comparison with state-of-the-art GRACE and combined gravity field models reveals the additional contribution of GOCE based on only 71 days of data. Compared with combined gravity field models, large deviations appear in regions where the terrestrial gravity data are known to be of low accuracy. The GOCE performance, assessed against the GRACE-only model ITG-Grace2010s, becomes superior at degree 150, and beyond. GOCE provides significant additional information of the global Earth gravity field, with an accuracy of the 2-month GOCE gravity field models of 10 cm in terms of geoid heights, and 3 mGal in terms of gravity anomalies, globally at a resolution of 100 km (degree/order 200).

Quantitative benchmark computations of two-dimensional bubble dynamics

Abstract: Benchmark configurations for quantitative validation and comparison of incompressible interfacial flow codes, which model two-dimensional bubbles rising in liquid columns, are proposed. The benchmark quantities: circularity, center of mass, and mean rise velocity are defined and measured to monitor convergence toward a reference solution. Comprehensive studies are undertaken by three independent research groups, two representing Eulerian level set finite-element codes and one representing an arbitrary Lagrangian-Eulerian moving grid approach.