المؤلفون: Scabbia F., Zaccariotto M., Galvanetto U., Bobaru F.

المساهمون: Scabbia, F., Zaccariotto, M., Galvanetto, U., Bobaru, F.

مصطلحات موضوعية: Nonlocal Boundary Condition, Peridynamic, Surface Effect, Surface Node Method, Wave Propagation

الوصف: Peridynamics is a novel nonlocal theory able to deal with discontinuities, such as crack initiation and propagation. Near the boundaries, due to the incomplete nonlocal region, the peridynamic surface effect is present, and its reduction relies on using a very small horizon, which ends up being expensive computationally. Furthermore, the imposition of nonlocal boundary conditions in a local way is often required. The surface node method has been proposed to solve both the aforementioned issues, providing enhanced accuracy near the boundaries of the body. This method has been verified in the cases of quasi-static elastic problems and diffusion problems evolving over time, but it has never been applied to a elastodynamic problems. In this work, we show the capabilities of the surface node method to solve a peridynamic problem of elastic wave propagation in a homogeneous body. The numerical results converge to the corresponding peridynamic analytical solution under grid refinement and exhibit no unphysical fluctuations near the boundaries throughout the whole timespan of the simulation.

وصف الملف: ELETTRONICO

العلاقة: info:eu-repo/semantics/altIdentifier/isbn/9781644902677; ispartofbook:Materials Research Proceedings; 3rd Aerospace PhD-Days 2023, International Congress of PhD Students in Aerospace Science and Engineering; volume:33; firstpage:347; lastpage:354; numberofpages:8; serie:MATERIALS RESEARCH PROCEEDINGS; https://hdl.handle.net/11577/3506334Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85176132181

الإتاحة: https://doi.org/10.21741/9781644902677-51Test
https://hdl.handle.net/11577/3506334Test

المؤلفون: Boschi, Lapo, Molinari, Irene, Reinwald, Michael

المساهمون: Boschi, Lapo, Molinari, Irene, Reinwald, Michael

مصطلحات موضوعية: Earthquake dynamic, Earthquake source observation, Theoretical seismology, Wave propagation, Geophysic, Geochemistry and Petrology

وصف الملف: ELETTRONICO

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000448242600001; volume:215; issue:1; firstpage:1; lastpage:21; numberofpages:21; journal:GEOPHYSICAL JOURNAL INTERNATIONAL; http://hdl.handle.net/11577/3290902Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85056541626; http://gji.oxfordjournals.orgTest/

الإتاحة: https://doi.org/10.1093/gji/ggy261Test
http://hdl.handle.net/11577/3290902Test
http://gji.oxfordjournals.orgTest/

المؤلفون: Kastle, ED, Molinari, I, Boschi, L, Kissling, E

المساهمون: Kastle, Ed, Molinari, I, Boschi, L, Kissling, E

مصطلحات موضوعية: Seismic anisotropy, Seismic interferometry, Seismic tomography, Wave propagation, Continental tectonics: compressional

الوصف: Ambient-noise records from the AlpArray network are used to measure Rayleigh wave phase velocities between more than 150 000 station pairs. From these, azimuthally anisotropic phase-velocity maps are obtained by applying the eikonal tomography method. Several synthetic tests are shown to study the bias in the Psi(2) anisotropy. There are two main groups of bias, the first one caused by interference between refracted/reflected waves and the appearance of secondary wave fronts that affect the phase traveltime measurements. This bias can be reduced if the amplitude field can be estimated correctly. Another source of error is related to the incomplete reconstruction of the traveltime field that is only sparsely sampled due to the receiver locations. Both types of bias scale with the magnitude of the velocity heterogeneities. Most affected by the spurious Psi(2) anisotropy are areas inside and at the border of low-velocity zones. In the isotropic velocity distribution, most of the bias cancels out if the azimuthal coverage is good. Despite the lack of resolution in many parts of the surveyed area, we identify a number of anisotropic structures that are robust: in the central Alps, we find a layered anisotropic structure, arc-parallel at mid-crustal depths and arc-perpendicular in the lower crust. In contrast, in the eastern Alps, the pattern is more consistently E-W oriented which we relate to the eastward extrusion. The northern Alpine forleand exhibits a preferential anisotropic orientation that is similar to SKS observations in the lower most crust and uppermost mantle.

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000763888200010; volume:229; issue:1; firstpage:151; lastpage:170; numberofpages:20; journal:GEOPHYSICAL JOURNAL INTERNATIONAL; http://hdl.handle.net/11577/3440338Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85130604069

الإتاحة: https://doi.org/10.1093/gji/ggab453Test
http://hdl.handle.net/11577/3440338Test

المؤلفون: Alebrahim R., Packo P., Zaccariotto M., Galvanetto U.

المساهمون: Alebrahim, R., Packo, P., Zaccariotto, M., Galvanetto, U.

مصطلحات موضوعية: Dispersion behavior, Minimization algorithm, Peridynamic, Wave propagation

الوصف: In this study, a novel method for improving the simulation of wave propagation in Peridynamic (PD) media is investigated. Initially, the dispersion properties of the nonlocal Bond-Based Peridynamic model are computed for 1-D and 2-D uniform grids. The optimization problem, developed through inverse analysis, is set up by comparing exact and numerical dispersion and minimizing the error. Various weighted residual techniques, i.e., point collocation, sub-domain collocation, least square approximation and the Galerkin method, are adopted and the modification of the wave dispersion is then proposed. It is found that the proposed methods are able to significantly improve the description of wave dispersion phenomena in both 1-D and 2-D PD models.

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000692075900001; numberofpages:18; journal:COMPUTATIONAL PARTICLE MECHANICS; https://hdl.handle.net/11577/3399425Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85114106855

الإتاحة: https://doi.org/10.1007/s40571-021-00433-xTest
https://hdl.handle.net/11577/3399425Test

المؤلفون: MONTANARO, ADRIANO, Dipartimento di Matematica, University of Padua, Giorgi, Claudio, Dipartimento di Ingegneria Civile, Ambiente e. Territorio, Arcitettura e. di Matematica, University of Brescia

المساهمون: Montanaro, Adriano, Dipartimento di Matematica, University of Padua, Giorgi, Claudio, Dipartimento di Ingegneria, Civile, Ambiente e., Territorio, Arcitettura e., di Matematica, University of, Brescia

مصطلحات موضوعية: Finite thermoelectroelasticity, Green–Naghdi types II and III model, heat conduction, piezothermoelasticity, thermal wave propagation

الوصف: In this article we extend the theory of thermoelasticity devised by Green and Naghdi to the framework of finite thermoelectroelasticity. Both isotropic and transversely isotropic bodies are considered and thermodynamic restrictions on their constitutive relations are obtained by virtue of the reduced energy equality. In the second part, a linearized theory for transversely isotropic ther- mopiezoelectricity is derived from thermodynamic restrictions by construct- ing the free energy as a quadratic function of the 11 second-order invariants of the basic melds. The resulting theory provides a natural extension of the (linear) Green and Naghdi theory for types II and III rigid heat conductors. As a particular case, we derive the linear system which rules the processes depending on the symmetry axis coordinate only.

وصف الملف: ELETTRONICO

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000382189000003; volume:39; issue:9; firstpage:1051; lastpage:1073; numberofpages:23; journal:JOURNAL OF THERMAL STRESSES; http://hdl.handle.net/11577/3198933Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84979645710

الإتاحة: https://doi.org/10.1080/01495739.2016.1192848Test
http://hdl.handle.net/11577/3198933Test

المؤلفون: MONTANARO, ADRIANO

المساهمون: Montanaro, Adriano

مصطلحات موضوعية: piezoelectromagnetism, wave propagation, time harmonic plane waves, crystal class 2

الوصف: In a piezoelectromagnetic crystalline medium belonging to the class 2 of the monoclinic crystallographic system we find some classes of piezoelectricity-induced electromagnetic waves. These are time harmonic plane waves propagating along the symmetry axis and depending only on the axial coordinate. There are two indepen- dent modes of propagation, one longitudinal and one transverse, with mechanical and electromagnetical couplings. The transverse mode admits as a particular case an electromagnetic wave with no associated elastic deformation.

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000356751900001; volume:67; issue:3; firstpage:1; lastpage:16; numberofpages:16; journal:ARCHIVES OF MECHANICS; http://hdl.handle.net/11577/3195467Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84930348958; http://am.ippt.pan.pl/am/article/view/v67p197Test

الإتاحة: http://hdl.handle.net/11577/3195467Test
http://am.ippt.pan.pl/am/article/view/v67p197Test

المؤلفون: Alebrahim R., Packo P., Zaccariotto M., Galvanetto U.

المساهمون: Alebrahim, R., Packo, P., Zaccariotto, M., Galvanetto, U.

مصطلحات موضوعية: minimization algorithm, numerical analysi, optimization, Peridynamic, wave propagation

الوصف: In this study, methods to mitigate anomalous wave propagation in 2-D Bond-Based Peridynamics (PD) are presented. Similarly to what happens in classical non-local models, an irregular wave transmission phenomenon occurs at high frequencies. This feature of the dynamic performance of PD, limits its potential applications. A minimization method based on the weighted residual point collocation is introduced to substantially extend the frequency range of wave motion modeling. The optimization problem, developed through inverse analysis, is set up by comparing exact and numerical dispersion curves and minimizing the error in the frequency-wavenumber domain. A significant improvement in the wave propagation simulation using Bond-Based PD is observed.

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000682929100001; firstpage:095440622098555; journal:PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS. PART C, JOURNAL OF MECHANICAL ENGINEERING SCIENCE; http://hdl.handle.net/11577/3387309Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85099942489

الإتاحة: https://doi.org/10.1177/0954406220985551Test
http://hdl.handle.net/11577/3387309Test

المؤلفون: Pirzadeh A., Boroomand B.

المساهمون: Pirzadeh, A., Boroomand, B.

مصطلحات موضوعية: Composite, Exponential basis function, High frequency, Impulsive load, Meshle, Plate, Wave propagation, Zig-Zag theory

الوصف: In this paper, a boundary node method is presented to study wave propagation in laminated composite plates. The Zig-Zag theory of Cho and Parmerter is used for deriving the governing equations of laminated plates. To the best of the authors’ knowledge, this study is the first one employing the theory in non-stationary dynamic plate problems addressing wave propagation issues. For this theory, there is no information about the Green’s functions and thus the presented method can be considered as an alternative to the boundary integral method. With the use of exponential basis functions (EBFs), the response of the structure is first found in the frequency domain and finally the time-domain response is obtained using inverse Fourier transformation. The EBFs are found so that they satisfy the governing equations in the frequency domain. For the first time, in this paper, we shall present explicit relations for the EBFs in the frequency domain for Cho and Parmerter’s Zig-Zag theory. The coefficients of the EBFs are found through the collocation of the boundary conditions. The dynamic analysis of some composite laminated plates is presented, and the results are compared to those obtained from the dynamic analysis of two-/three-dimensional finite element method (FEM). We shall discuss the capabilities and limitations of the theory and the solution method. The capability of the method, in the analysis of problems excited by high-frequency loads, is shown in the solution of wave propagation problems for which the FEM needs excessive number of elements and thus it is practically impossible to be applied.

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000520179000001; volume:90; issue:4; firstpage:651; lastpage:672; numberofpages:22; journal:ARCHIVE OF APPLIED MECHANICS; http://hdl.handle.net/11577/3405275Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85075123221

الإتاحة: https://doi.org/10.1007/s00419-019-01632-yTest
http://hdl.handle.net/11577/3405275Test

المؤلفون: Mossaiby F., Shojaei A., Boroomand B., Zaccariotto M., Galvanetto U.

المساهمون: Mossaiby, F., Shojaei, A., Boroomand, B., Zaccariotto, M., Galvanetto, U.

مصطلحات موضوعية: Absorbing boundary condition, Elastic wave propagation, Finite element method, Meshless method, Time domain, Unbounded domains

الوصف: In this paper a new collocation technique for constructing time-dependent absorbing boundary conditions (ABCs) applicable to elastic wave motion is devised. The approach makes use of plane waves which satisfy the governing equations of motion to construct the absorbing boundary conditions. The plane waves are adjusted so that they can cope with the satisfaction of radiation boundary conditions. The proposed technique offers some advantages and exhibits the following features: it is easy to implement; its approximation scheme is local in space and time and thus it does not deal with any routine schemes such as Fourier and Laplace transform, making the method computationally less demanding; as the employed basis functions used to construct the absorbing boundary condition are residual-free, it requires neither any differential operator (to approximate the wave dispersion relation), nor any auxiliary variables; it constructs Dirichlet-type ABCs and hence no derivatives of the field variables are required for the imposition of radiation conditions. In this study, we apply the proposed technique to the solution procedure of a collocation approach based on the finite point method which proceeds in time by an explicit velocity-Verlet algorithm. It contributes to developing a consistent meshless framework for the solution of unbounded elastodynamic problems in time domain. We also apply the proposed method to a standard finite element solver. The performance of the method in solution of some 2D examples is examined. We shall show that the method exhibits appropriate results, conserves the energy almost exactly, and it performs stably in time even in the case of long-term computations.

وصف الملف: STAMPA

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000515542500024; volume:362; firstpage:112856; journal:COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING; http://hdl.handle.net/11577/3335787Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85078232500

الإتاحة: https://doi.org/10.1016/j.cma.2020.112856Test
http://hdl.handle.net/11577/3335787Test

المؤلفون: SCHREFLER, BERNHARD, MAIORANA, CARMELO, SANAVIA, LORENZO

المساهمون: Schrefler, Bernhard, Maiorana, Carmelo, Sanavia, Lorenzo

مصطلحات موضوعية: dynamic strain localisation, multiphase porous media, continuum wave propagation, acoustic tensor, finite element analysis

الوصف: A computational analysis of dynamic strain localization in multiphase solids is presented in this paper. The governing equations are obtained by means of averaging theories based on spatial averaging operators. Continuum wave propagation is used for the study of localization. The directions of localization are obtained by means of an eigenvalue analysis of the acoustic tensor. The investigation of the development of localized bands is carried out by means of a finite element code. The influence on localization of coupling between the constituents is studied. Several examples are shown

وصف الملف: STAMPA

العلاقة: volume:47; issue:3; firstpage:577; lastpage:599; numberofpages:23; journal:ARCHIVES OF MECHANICS; http://hdl.handle.net/11577/2473462Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0000167220; http://am.ippt.gov.pl/index.php/amTest; https://www.scopus.com/record/display.uri?eid=2-s2.0-0000167220&origin=resultslistTest

الإتاحة: http://hdl.handle.net/11577/2473462Test
http://am.ippt.gov.pl/index.php/amTest
https://www.scopus.com/record/display.uri?eid=2-s2.0-0000167220&origin=resultslistTest