none3noN.A.mixedTrovalusci P.; Fantuzzi N.; De Bellis M.L.Trovalusci P.; Fantuzzi N.; De Bellis M.L

De Bellis M. L.

Fantuzzi N.

Trovalusci P.

English

Archivio istituzionale della ricerca - Alma Mater Studiorum Università di Bologna

Preface: Multiscale and multiphysics modeling of “complex” materials and engineering applications

Archivio della ricerca- Università di Roma La Sapienza

InternationalJournal for Multiscale Computational Engineering, 18(1):v–ix (2020)PREFACE: MULTISCALE AND MULTIPHYSICSMODELING OF “COMPLEX” MATERIALS ANDENGINEERING APPLICATIONSThe present volume is a special issue of selected papers from the 11th edition of a special symposium session, “Mul-tiscale and Multiphysics Modeling for Complex Materials,” organized within the framework of the 9th InternationalConference on Computational Methods (ICCM2018), held in Rome, Italy, in August 2018, with Professor Trovaluscias chairman. The early focus of the symposium was to bridge the gap between solid mechanics and materials science,providing a forum for the presentation of fundamental, theoretical, experimental, and practical aspects of mechanicalmodeling of materials with complex microstructures and complex behavior.Among various invited and contributing authors, the conference featured plenary lectures by Professors SomnathGhosh, from Johns Hopkins University of Baltimore, Maryland, USA; Paulo B. Lourenço, of the University of Minho,Portugal; and Siegfried Schmauder, from the Institute for Materials Testing, Materials Science and Strength of Mate-rials (IMWF), University of Stuttgart, Germany. All these lecturers also contributed to this special issue. The issue isdivided into two separate volumes due to the number of contributions attracted. Globally, the whole issue collects fif-teen articles by selected invited authors who participated in the mentioned symposium session as well as others. Eachcontribution has undergone a standard review process, and only papers which received positive recommendations fromat least two international referees were included.These contributions provide a survey of the multiscale approaches proposed to describe materials with variousinternal structures at different scales (nano/micro, meso, macro), from composite, to shape memory, to masonry-likematerials, and with complex behaviors such as plasticity, damage, fracture, and phase transformation. Most of thepapers aim at detecting the structural performances of advanced materials in various engineering applications rangingfrom microelectronics to civil engineering. The articles are briefly introduced in the paragraphs below.Ghosh and Guo (2019) [1] develop a finite element model for coupled electromechanical systems. Transient dy-namic simulations are performed by considering continuum damage relations, which are needed as a field-based vir-tual damage sensor. The code is validated by comparing with analytical results and those from commercial software.An electric field–based damage indicator function is proposed and calibrated from data obtained through numericalsolutions. The function relates the electric field difference for undamaged and damaged conditions to the damage pa-rameter, its rate, and mechanical and piezoelectric material properties. The virtual damage sensor is used to examinedamage conditions in a stretchable piezoelectric serpentine conductor.Lourenço and Silva (2020) [2] present a set of advanced models for the mechanical study of masonry, includ-ing the usual micromodeling approaches, macromodeling, and multiscale techniques. An extensive overview of itscomputational features is provided. The engineering application of such strategies is presented and covers problemsstarting from the masonry components level (mesoscale) to the structural element itself, and ultimately to the levelof monumental buildings (super large). The structural safety assessment and/or strengthening schemes evaluated areperformed amid the static, slow dynamics or earthquakes and fast dynamics or impact and blast ranges.Haoyun et al. (2020) [3] adopt a 3D digital image correlation (DIC) system for investigating the fracture behaviorof structural steel S355. The DIC system captures the crack propagation and strain field variation on the surface of aside grooved compact tension [C(T)] specimen. The 2D and 3D Gurson-Tvergaard-Needleman (GTN) model is usedto simulate the ductile fracture of the specimen and the shape of the stable crack growth region. The DIC techniqueallows the strain variation and crack propagation on the specimen surface to be obtained. A comparison betweenexperimental data and numerical simulation results shows that the GTN well describes the ductile fracture behaviorof the C(T) specimen from S355.The article by Spanos et al. (2020) [4] deals with the determination of the effective electrical and thermal conduc-tivity of reinforced carbon nanotube (CNT) nanocomposites using a numerical percolation approach and Monte Carlo1543–1649/20/$35.00 c⃝ 2020 by Begell House, Inc. www.begellhouse.com vvi Trovalusci, Fantuzzi, & De Bellissimulation. A nanocomposite representative volume element (RVE) is generated in a 3D spatial domain accordingto given input parameters. Connections among nanotubes are modeled using a spanning network algorithm. Inter-connected nanotubes are converted into equivalent resistor networks to determine the effective electrical or thermalconductivity. Statistical variation at each volume fraction of nanotube filler is taken into account via Monte Carlosimulations. The effect of various microstructural parameters is investigated, the RVE size is optimized, and resultsare validated by comparison to experimental data from the literature.In the article by Barretta et al. (2020) [5], a strain gradient model based on both Eringen’s and Lam’s nonlocalmodified strain gradient formulation is provided. The present theoretical framework is based on three scale parameterswhich describe nonlocality, dilatation, and stretch gradient. It has been shown that these parameters significantly affectthe response of one-dimensional nanorods. The problem is formulated through a variationally consistent approachbased on suitably selected test fields, projected for formulating well-posed static and dynamic problems of engineeringinterest. Exact solutions are provided in terms of nonlocal and gradient characteristic parameters. Validation of theproposed strategy is carried out by comparing the contributed results with those obtained by the modified nonlocalstrain gradient theory.The work by Pisano et al. (2020) [6] represents a contribution in the field of nonlocal elasticity theory for thedescription of size effects in small-scale beams. The work is focused on the extension of a strain-difference–basednonlocal elasticity theory, previously developed by the authors, to the case of shear-deformable beams by incorporat-ing a parametric warping model. The formulation covers a variety of beam modeling assumptions, ranging from theEuler-Bernoulli beam to the Timoshenko beam as limiting cases. The boundary value problem equations are solved bya set of eight uncoupled auxiliary integral equations independent of the boundary conditions. Numerical solutions forsimple beam problems are reported with particular concern to size effects and to their sensitivity to shear deformation.In the paper by Aminpour and Rizzi (2020) [7], a one-dimensional continuum model endowed with internalstructure is proposed as a coarse descriptor of the necking of graphene nanostructures under tension in the nonlinearelasticity framework. The paper focuses on the postbuckling behavior of graphene sheets undergoing uniaxial tensionloadings, but the procedure can be applied to other two-dimensional graphene nanostructures, as nanoribbons ornanotubes. The interatomic actions are described by the modified Morse potential, and the strain energy density of aRVE is given in terms of nanoscopic strain measures, expressed as a function of continuum strain measures thoroughsuitable relationships between the discrete and continuum kinematics. A perturbation analysis is performed to obtainthe first bifurcation point on the trivial equilibrium path, together with the initial tangent to the bifurcated path. Apeculiar postbuckling behavior is detected and discussed.The work by Mazzucco et al. (2020) [8] discusses a multilevel procedure, characterized by the adoption of laserscanner techniques combined with CAD, X-ray computed tomography, and a particle random disposition algorithm.Such a framework reproduces an exact finite element model of concrete at the mesoscale in terms of particles packingand representation of material heterogeneities, together with a nonlinear constitutive characterization developed withinthe framework of nonassociated plasticity coupled with damage. The approach is tested on a typical application ofstructural failure in confined conditions under extreme mechanical loads.Formica et al. (2020) [9] propose an optimization of the storage modulus and hysteretic damping capacity ofcarbon nanotube (CNT) nanocomposites. The analysis is proposed via a differential evolution algorithm coupled withan ad hoc finite element implementation of a nonlinear 3D mesoscale theory. Such theory describes the hysteresis dueto the shear stick-slip between the nanotubes and the hosting matrix. The optimization problem seeks to determinethe set of material parameters of a multilayer stacking sequence that can give rise to the largest storage modulus anddamping capacity of the nanocomposite. The results confirm that the genetic-type multilayer nanocomposite dampingoptimization can be an effective design method.In the work by Addessi et al. (2020) [10], a multiscale model for the analysis of the in-plane response of pe-riodic masonry walls is presented. The overall constitutive behavior of the composite material is derived through ahomogenization procedure based on the transformation field analysis (TFA) extended to the case of interfaces. A non-linear constitutive law accounting for damage and friction phenomena is considered for joints, whereas a linear elasticconstitutive relationship is assumed for the blocks. The proposed multiscale procedure is implemented into a finiteelement code. Validation examples are carried out: First, the response is analyzed comparing results obtained with thepresented homogenization procedure with those recovered by detailed nonlinear finite element analysis. Second, theInternational Journal for Multiscale Computational EngineeringMultiscaleand Multiphysics Modeling viistructural behavior of masonry panels subjected to compression-shear loads is studied. The reliability and numericalaccuracy of the proposed approach are shown by providing different validation examples, referring to both unit-celland structural scales.The paper by Callari and Froiio (2020) [11] focuses on simulating the localization of propagating internal erosionin rigid porous media. The interaction between backward erosion piping and soil movement is also modeled. Exchangeand transport of solid and fluid mass equations in a saturated poro-elasto-plastic solid embedding a propagating erosionconduit conveying a multiphase flow is analyzed. A numerical finite element framework was set up to solve the relatedcoupled equations. The performance of the proposed formulation is assessed through an analysis of the soil responseto the progressive dewatering of a cofferdam. The hydromechanical coupling and the ability to capture both the onsetand propagation of piping are crucial for an interpretation of the limiting states typically observed in these structures.Li et al. (2020) [12] present the framework of a second-order concurrent computational homogenization methodfor saturated granular materials. A staggered discrete element method (DEM) / finite element method (FEM) solu-tion scheme is proposed for nonlinear hydromechanical analysis of saturated discrete particle assembly. The effectivestress measures with the elastoplastic modular tensor, volume averages of pore pressures, and Darcy’s velocities withthe permeability coefficient tensor are determined and upscaled to a high scale. A FEM-(DEM/FEM) nested solu-tion scheme is devised for the proposed second-order concurrent computational homogenization method. Numericalexamples and results demonstrate the capabilities and performances of the proposed method in multiscale model-ing of hydromechanical behaviors, particularly, softening and localization behaviors occurring in saturated granularstructures.The work by Chisari et al. (2020) [13] deals with the structural response of masonry structures under extremeloading conditions, such as seismic events. A multiscale approach is proposed in which an accurate mesoscale model,accounting for the specific masonry bonds, is utilized in virtual tests for the calibration of material parameters ofa macroscale model, assuming energy equivalence between the two scales. The proposed methodology is appliedto a case study considering the results obtained in previous experimental tests on masonry components subjectedto cyclic loading and on a masonry building under pseudodynamic conditions to represent earthquake loading. Theresults confirm the potential of the proposed approach, computationally attractive compared to other homogenizationtechniques, and highlight some critical issues, such as the importance of selecting appropriate virtual tests for modelcalibration, which can significantly influence accuracy and robustness.In the paper by Fantuzzi et al. (2020) [14], advantages of micropolar theory in modeling anisotropic compositematerials with local rigid microstructure are discussed. This study focuses on composites made of hexagonal rigidparticles which interact among themselves through elastic interfaces so that the deformation energy of the material isconcentrated only at the interfaces. Three particle geometries are investigated, such as orthotetragonal, auxetic, andchiral. Novel results have been achieved by presenting the behavior of panels with various material symmetries underlocalized loads.Huang et al. (2020) [15] present a multiphysics and multiscale design strategy. First fluid flow is coupled withheat transfer in both fluids and solids. The component is optimized for performance with such integrated multiphysicscoupled models. Then, the optimized component is modeled only for its structural reliability using a “top-down”approach that begins from an elastic solution, followed by a more detailed and coupled elastoplastic continuum modelfor the critical zone, and then finally modeled at the microscale to reveal the effects of the material microstructure.A design example is shown for a modular plasma-facing component in a fusion energy device (plasma divertor).The cooled unit has a microengineered tungsten foam protective tile on top of solid tungsten closed tubing with heatremoval internals.We hope these research issues will provide opportunities to identify and discuss future developments in the fieldof multiscale modeling and design of advanced materials.ACKNOWLEDGMENTSOur special thanks go to the editor-in-chief, Jacob L. Fish, for inviting us to select and collect papers for this specialissue and for assisting us in the editing work. P. Trovalusci acknowledges the support of PRIN 201 Grant, projectVolume 18, Issue 1, 2020viii Trovalusci, Fantuzzi, & De Bellis2017HFPKZY (B86J16002300001) and Sapienza Research Grants “Progetti Medi” 2017 (B83C17001440005) and“Progetti Grandi” 2018 (B81G19000060005).Guest Editor:Patrizia TrovalusciDepartment of Structural Engineering and GeotechnicsSapienza University of RomeVia Gramsci 53, 00197 Rome, ItalyCo-Guest Editors:Nicholas FantuzziDepartment of Civil, Chemical, Environmental and Materials EngineeringUniversity of BolognaViale del Risorgimento 2, 40136 Bologna, ItalyMaria Laura De BellisDepartment of Engineering and GeologyUniversity “G. D’Annunzio” of Chieti and PescaraViale Pindaro 42, 65127 Pescara, ItalyARTICLES IN THIS ISSUE1. Ghosh, S. and Guo, S., Developing a Virtual Damage Sensor Using a Coupled Electro-Mechanical Fe Model of a PiezoelectricMaterial.2. Lourenço, P.B. and Silva, L.C., Computational Applications in Masonry Structures: From the Meso-Scale to the Super-Large/Super-Complex.3. Haoyun, T.H., Schmauder, S., Li, Y., and Zhou, H., Digital Image Correlation Tracking and Gurson-Tvergaard-NeedlemanModelling of Crack Propagation on Steel S355.4. Spanos, P., Higginson, C., Ketron, T., and Roy, A., 3A Resistor Network Computational Model for the Determination ofElectrical and Thermal Properties of Nanocomposites.5. Barretta, R., Faghidian, A., Marotti de Sciarra, F., and Pinnola, F.P., On Nonlocal Lam Strain Gradient Mechanics of ElasticRods.6. Pisano, A.A., Fuschi, P., and Polizzotto, C., A Strain-Difference based Nonlocal Elasticity Theory for Small-Scale Shear-Deformable Beams with Parametric Warping.7. Aminpour, H. and Rizzi, N.L., On the Necking of Graphene Nanostructures.8. Mazzucco, G., Pomaro, B., Xotta, G., Salomoni, V.A., and Majorana, C.E., An Efficient Geometric Reconstruction ofMesoscale Concrete Structures Accounting for Confinement Scenarios.9. Formica, G., Milicchio, F., and Lacarbonara, W., Storage and Damping Optimization in Hysteretic Multilayer Nanocompos-ites.10. Addessi, A., Gatta, C., Marfia, S., and Sacco, E., Multiscale Analysis of In-Plane Masonry Walls Accounting for Degradationand Frictional Effects.11. Callari, C. and Froiio, F., A Hydro-Mechanical Finite Element Formulation for Localized Internal Erosion in Porous Media,with Application to Backward Piping in Cofferdams.12. Li, X., Zhang, S., and Duan, Q., Second-Order Concurrent Computational Homogenization Method and Multi-Scale Hydro-Mechanical Modeling for Saturated Granular Materials.International Journal for Multiscale Computational EngineeringMultiscaleand Multiphysics Modeling ix13. Chisari, C., Macorini, L., and Izzuddin, B.A., Multiscale Model Calibration by Inverse Analysis for Nonlinear Simulation ofMasonry Structures under Earthquake Loading.14. Fantuzzi, N., Trovalusci, P., and Luciano, R., Multiscale Analysis of Anisotropic Materials with Hexagonal Microstructure asMicro-Polar Continua.15. Huang, Y., Nadvornick, W., Ghazari, A., and Ghoniem, N., Multiphysics-Multiscale Modeling of Plasma-Facing Structuresin Extreme Heat and Radiation Environments.Volume 18, Issue 1, 2020

https://iris.uniroma1.it/bitstream/11573/1506100/1/Trovalusci_Multiscale_2020.pdf

Preface: Multiscale and multiphysics modeling of “complex” materials and engineering applications

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Alma Mater Studiorum Università di Bologna

Archivio della ricerca- Università di Roma La Sapienza