2D kinematics of the edge-on spiral galaxy ESO 379-G006

We present a kinematical study of the nearly edge-on galaxy ESO 379-G006 that shows the existence of extraplanar ionized gas. With Fabry-Perot spectroscopy at H-alpha, we study the kinematics of ESO 379-G006 using velocity maps and position-velocity diagrams parallel to the major and to the minor axis of the galaxy. We build the rotation curve of the disk and discuss the role of projection effects due to the fact of viewing this galaxy nearly edge-on. The twisting of the isovelocities in the radial velocity field of the disk of ESO 379-G006 as well as the kinematic asymmetries found in some position-velocity diagrams parallel to the minor axis of the galaxy suggest the existence of deviations to circular motions in the disk that can be modeled and explained with the inclusion of a radial inflow probably generated by a bar or by spiral arms. We succeeded in detecting extraplanar Diffuse Ionized Gas in this galaxy. At the same time, from the analysis of position-velocity diagrams, we found some evidence that the extraplanar gas could lag in rotation velocity with respect to the midplane rotation.Comment: 61 pages, 15 figures. Accepted for publication in A

Elastoplastic analysis of compact and thin-walled structures using classical and refined beam finite element models

The paper presents results on the elastoplastic analysis of compact and thin-walled structures via refined beam models. The application of Carrera Unified Formulation (CUF) to perform elastoplastic analysis of isotropic beam structures is discussed. Particular attention is paid to the evaluation of local effects and cross-sectional distortions. CUF allows formulation of the kinematics of a one-dimensional (1D) structure by employing a generalized expansion of primary variables by arbitrary cross-section functions. Two types of cross-section expansion functions, TE (Taylor expansion) and LE (Lagrange expansion), are used to model the structure. The isotropically work-hardening von Mises constitutive model is incorporated to account for material nonlinearity. A Newton–Raphson iteration scheme is used to solve the system of nonlinear algebraic equations. Numerical results for compact and thin-walled beam members in plastic regime are presented with displacement profiles and beam deformed configurations along with stress contour plots. The results are compared against classical beam models such as Euler–Bernoulli beam theory and Timoshenko beam theory, reference solutions from literature, and three-dimensional (3D) solid finite element models. The results highlight: (1) the capability of the present refined beam models to describe the elastoplastic behavior of compact and thin-walled structures with 3D-like accuracy; (2) that local effects and severe cross-sectional distortions can be detected; (3) the computational cost of the present modeling approach is significantly lower than shell and solid model ones

Who needs refined structural theories?

This paper discusses the question posed in the title and available options for the structural analysis of metallic and composite structures concerning the choice of 1D, 2D, and 3D theories. The focus is on the proper modeling of various types of mechanical behaviors and the associated solution’s efficiency. The necessity and convenience of developing higher‐order structural theories are discussed as compared to 3D models. Multiple problems are considered, including linear and nonlinear analyses and static and dynamic settings. Some possible guidelines on the proper selection of a model are outlined, and quantitative estimations on the accuracy are provided. It is demonstrated that the possibility of incorporating higher‐order effects in 1D and 2D models continues to remain attractive in many structural engineering problems to alleviate the computational burdens of 3D analyses

Spatially resolved LMC star formation history: I. Outside in evolution of the outer LMC disk

We study the evolution of three fields in the outer LMC disk Rgc=3.5-6.2 Kpc. Their star formation history indicates a stellar populations gradient such that younger stellar populations are more centrally concentrated. We identify two main star forming epochs, separated by a period of lower activity between ~7 and ~4 Gyr ago. Their relative importance varies from a similar amount of stars formed in the two epochs in the innermost field, to only 40% of the stars formed in the more recent epoch in the outermost field. The young star forming epoch continues to the present time in the innermost field, but lasted only till ~0.8 and 1.3 Gyr ago at Rgc=5.5 degrees and 7.1 degrees, respectively. This gradient is correlated with the measured HI column density and implies an outside-in quenching of the star formation, possibly related to a variation of the size of the HI disk. This could either result from gas depletion due to star formation or ram-pressure stripping, or from to the compression of the gas disk as ram-pressure from the Milky Way halo acted on the LMC interstellar medium. The latter two situations may have occurred when the LMC first approached the Milky Way.Comment: 15 pages, 13 figures, 4 tables. MNRAS, in pres

Preliminary Water Assessment Reports of The Test Basins of The Watch Project

This report presents the initial plans of the case studies how they link to rest of the Watch project and on which water resources they will focus. This report will function as the basis for further discussions on how to improve the integration of the case studies within the project and to develop a more general protocol for each of the case studies. Currently 5 catchments are used within the Watch project, they differ in climatic and hydro-geological features and expected climate changes: the Glomma River basin (Eastern Norway), the upper Guadiana basin (Central Spanish Plateau), the Nitra River basin (central Slovakia), the Upper-Elbe basin (part of the Elbe River) and the island of Crete. Also the water resources issues vary over these cases. Agricultural (and domestic) water use is under pressure in the Mediterranean catchments probably aggravating with the expected increase in drought frequency under future climate. The Norwegian catchment provides hydropower services under threat of precipitation increase rather than decrease. The central European catchments are threatened mainly by increased variability, i.e. increased frequencies of extremes in a densely populated environment, and river flow may need additional buffers (reservoirs) to reduce floodrisk and store water for dry period

Progressive delamination of laminated composites via 1D models

This paper presents a novel numerical framework to simulate the progressive delamination in laminated structures based on 1D component-wise models. The proposed numerical tool is a part of the virtual testing platform built within the Carrera Unified Formulation, a hierarchical, higher-order structural framework to generate theories of structures via a variable kinematic approach. Formulated within the Lagrange polynomial CUF models, the component-wise approach models the components of a complex structure through 1D CUF models at reduced computational costs and 3D-like accuracies. The effectiveness of CUF-CW models to capture accurate 3D transverse fields are of interest to solve delamination problems by integrating a class of higher-order cohesive elements to simulate the cohesive mechanics among the various components of the structure. The present framework adopts a bilinear constitutive law based on the mixed-mode delamination propagation and an efficient arc-length solver based on an energy-dissipation constraint. The numerical results aim to verify the accuracy and computational efficiency of CUF-CW models through benchmark composite delamination problems including multiple delamination fronts and comparisons with reference literature solutions and standard 3D FEM models. The outcomes show multi-fold improvements in the analysis times, good matches with experimental results, and promising enhancements of the meshing process due to the absence of aspect ratio constraints

Alpine reactivation of variscan folds and faults in the Iberian Chain: Examples of the Sierra de la Demanda and the Serrania de Cuenca

[Abstract] The structure of the Variscan basement of the Iberian Chain conditioned the geometry and orientation ofstructures formed during the Alpine compression. In the Sierra de la Demanda, located in the north-western part of the Iberian Chain, the E-W Variscan folds re-activated during the Tertiary compression, bringing about the folding of the mesozoic rocks uncomformably lying on them. In sorne sites this folds broke, forming high-angle thrusts. In the Boniches anticline (Serranía de Cuenca), Tertiary folding was conditioned by the existence of NW-SE basement faults, that moved under transpression. Variscan folding directions did not influence here the Tertiary deformational geometry

A global-local approach for the elastoplastic analysis of compact and thin-walled structures via refined models

A computationally efficient framework has been developed for the elastoplastic analysis of compact and thin-walled structures using a combination of global-local techniques and refined beam models. The theory of the Carrera Unified Formulation (CUF) and its application to physically nonlinear problems are discussed. Higher-order models derived using Taylor and Lagrange expansions have been used to model the structure, and the elastoplastic behavior is described by a von Mises constitutive model with isotropic work hardening. Comparisons are made between classical and higher-order models regarding the deformations in the nonlinear regime, which highlight the capabilities of the latter in accurately predicting the elastoplastic behaviour. The concept of global-local analysis is introduced, and two versions are presented - the first where physical nonlinearity is considered for both the global and local analyses, and the second where nonlinearity is considered only for the local analysis. The second version results in reasonably accurate results compared to a full 3D finite element analysis, with a twofold reduction in the number of degrees of freedom