MUSAM - Multi-scale Analysis of Materials


MUSAM is a research unit of engineers, physicists and applied mathematicians researching the multi-scale and multi-physics characterization of materials. Topics of investigation regard the deformation, fracture, fatigue, contact and structural integrity of heterogeneous materials and structures, coatings, material microstructures and devices. In addition to computational tools developed in-house (finite element method, boundary element method, molecular dynamics), the experimental facilities available in the laboratory include mechanical testing machines, a scanning electron microscope, a confocal and interferometric profilometer, a digital image correlation system and a high resolution thermocamera. This research is applied to areas of civil, mechanical, aerospace and electronic engineering, renewable energy systems and geophysics.

Composed of engineers, physicists and mathematicians, the unit aims at studying the deformation, fracture, fatigue, contact and the structural integrity of heterogeneous materials and structures with multi-scale and multi-physics computational and experimental methods.


  • Prof. Dr. Ing. Marco Paggi (Director)
  • Dr. Ing. Andrea Bacigalupo, Assistant Professor
  • Dr. Irene Berardone, Post-doc
  • Dr. Claudia Borri, Post-doc
  • Dr.-Ing. Pattabhi R. Budarapu, Post-doc
  • Dr. Ing. Francesca Fantoni, Post-doc
  • Dr. Ing. Mariacristina Gagliardi, Post-doc
  • Dr. Ing. Saheed Olalekan Ojo, Post-doc
  • Dr. Lorenzo Morini, Post-doc
  • Pietro Lenarda, PhD student, cycle XXIX
  • Ing. Valerio Carollo, PhD student, cycle XXX
  • Ing. Paolo Cinat, PhD student, cycle XXX
  • Ing. Vigneswaran Govindarajan, PhD student, cycle XXX
  • Ms. Rosaria Del Toro, PhD student, cycle XXXI
Visiting Professors and Visiting Scholars (past and present)
  • Prof. Dr. Ing. Davide Bigoni, Visiting Professor, Full Professor at the University of Trento (Trento, Italy)
  • Dr. Ing. Mauro Corrado, Visiting Professor, Assistant Professor at Politecnico di Torino and Marie Curie Fellow at the Ecole Polytechnique Fédérale de Lausanne (Lausanne, Switzerland)
  • Dr. Ing. Alessio Gizzi, Visiting Professor, Assistant Professor at the Università Campus Bio-Medico di Roma (Roma, Italy)
  • Dr. Ing. José Reinoso, Visiting Professor, Assistant Professor at the University of Seville (Seville, Spain)
  • Ing. Irene Berardone, Visiting Scholar, PhD student at Politecnico di Torino and DAAD scholar at the Institute for Solar Energy Research (Hameln, Germany)
  • Ing. Andrea Infuso, Visiting Scholar, PhD student at Politecnico di Torino and scholar at the University of Paris-Est (Marne-la-Vallée, France)
  • Ing. Saheed Olalekan Ojo, Visiting Scholar, PhD student at Politecnico di Torino (Torino, Italy)
Staff From left to right: Budarapu, Lenarda, Cinat, Bacigalupo, Paggi, Borri, Carollo, Govindarajan.

Research Topics

Multi-scale and multi-physics computational models
Mathematical modelling of coupled mechanical, thermal, hygrometric, and electromagnetic fields and implementation of the proposed formulations in the finite element method with novel staggered or fully coupled formulations. Particular attention is given to coupling driven by fracture events. Applications mainly concern photovoltaics and generalized diffusion problems in solids. Experimental facilities include high resolution electroluminescence and thermal imaging.

  • M. Paggi, I. Berardone, A. Infuso, M. Corrado (2014) Fatigue degradation and electric recovery in Silicon solar cells embedded in photovoltaic modules, Scientific Reports, 4, 4506 doi:10.1038/srep04506
  • I. Berardone, M. Corrado, M. Paggi (2014) A generalized electric model for mono and polycrystalline silicon in the presence of cracks and random defects, Energy Procedia, 55:22-29 doi:10.1016/j.egypro.2014.08.005
  • A. Sapora, M. Paggi (2014) A coupled cohesive zone model for transient analysis of thermoelastic interface debonding, Computational Mechanics, 53:845-857 doi:10.1007/s00466-013-0934-8

Multi-scale and multi-physics computational models
Thermal image of photovoltaic modules showing hot spots
Multi-scale and multi-physics computational models
Electroluminescence image of photovoltaic modules showing cracking

Contact mechanics of rough surfaces
Development of theoretical models and numerical methods based on FEM, BEM or molecular dynamics for the tribological characterization of rough surfaces including the prediction of the real contact area, thermal and electric contact conductances, as well as frictional instabilities. The modelling activities are complemented by experimental research according to the laboratory facilities consisting in a confocal-interferometric profilometer for multi-scale roughness measurement. Research includes the application of novel optimization algorithms to contact problems in collaboration with DYSCO research unit.

  • C. Borri, M. Paggi (2015) Topological characterization of antireflective and hydrophobic rough surfaces: are random process theory and fractal modeling applicable?, Journal of Physics D: Applied Physics, 48, 045301 doi:10.1088/0022-3727/48/4/045301
  • M. Paggi, R. Pohrt, V.L. Popov (2014) Partial-slip frictional response of rough surfaces, Scientific Reports, 4, 5178 doi:10.1038/srep05178
  • M. Ciavarella, J.A. Greenwood, M. Paggi (2008) Inclusion of “interaction” in the Greenwood and Williamson contact theory, Wear, 265:729-734 doi:10.1016/j.wear.2008.01.019

Contact mechanics of rough surfaces
Numerical simulation of contact problems

Numerical simulation of the nonlinear mechanical behavior (prediction of strength, toughness, stiffness) of heterogeneous material microstructures with special attention to polycrystalline materials. Research on computational homogenization techniques and on higher-order continua is coordinated by Dr. Ing. Bacigalupo. Experimental facilities available in the laboratory regard the possibility to observe the evolution of material microstructures by performing tensile/compression tests inside a scanning electron microscope. Materials already characterized are: polycrystalline Silicon for photovoltaics; polycrystalline diamond; innovative hierarchical polycystals for cutting tools; paper tissue.

  • A. Bacigalupo, L. Gambarotta (2014) Second-gradient homogenized model for wave propagation in heterogeneous periodic media, International Journal of Solids and Structures, 51:1052-1065 doi:10.1016/j.ijsolstr.2013.12.001
  • M. Paggi, E. Lehmann, C. Weber, A. Carpinteri, P. Wriggers, M. Schaper (2013) A numerical investigation of the interplay between cohesive cracking and plasticity in polycrystalline materials, Computational Materials Science, 77:81-92 doi:10.1016/j.commatsci.2013.04.002
  • M. Paggi, P. Wriggers (2012) Stiffness and strength of hierarchical polycrystalline materials with imperfect interfaces, Journal of the Mechanics and Physics of Solids, 60:557-572 doi:10.1016/j.jmps.2012.01.009

Numerical simulation of the nonlinear mechanical behaviour Numerical simulation of the nonlinear mechanical behaviour
Modelling of plasticity and fracture in polycrystalline materials

Composite materials
Development of linear and nonlinear fracture mechanics models for the study of delamination in layered, fibre-reinforced, functionally graded or retrofitted composite materials. Dr. Reinoso is coordinating research on decohesion between hyperelastic layers undergoing large deformation, and interplay between fracture and geometrical instabilities by coupling continuum shell elements and interface elements for fracture. Experimental facilities regard a universal testing machine for carrying our tensile, compression or three-point bending tests with two load cells (1 kN or 10 kN), also inside a thermostatic chamber (from -30°C to 250°C), and a digital image correlation system for non-contact displacements measurement. Applications regard: photovoltaic modules; metal matrix composites for aerospace; layered shells for naval engineering; fibre-reinforced concrete; retrofitting of civil structures.

  • M. Paggi, J. Reinoso (2015) An anisotropic large displacement cohesive zone model for fibrillar or crazing interfaces, International Journal of Solids and Structures, in press.
  • I.G. García, M. Paggi, V. Mantič (2014) Fiber-size effects on the onset of fiber–matrix debonding under transverse tension: A comparison between cohesive zone and finite fracture mechanics models, Engineering Fracture Mechanics, 115:96-110 doi:10.1016/j.engfracmech.2013.10.014
  • J. Reinoso, M. Paggi (2014) A consistent interface element formulation for geometrical and material nonlinearities, Computational Mechanics, 54:1569-1581 doi:10.1007/s00466-014-1077-2

Composite materials
Modelling of debonding between fibre and matrix in fibre-reinforced metal matrix composites

Multiscale fracture mechanics
Development of innovative computational methods for the simulation of fracture across multiple length scales. Dr.-Ing. Budarapu is coordinating research on coupling continuum finite elements and molecular dynamics for fracture mechanics simulations.

  • Y. Shih-Wei, P. Budarapu, D.R. Mahapatra, S. Bordas, G. Zi, T. Rabczuk (2015) A meshless adaptive multiscale method for fracture, Computational Materials Science, 96:382-95 doi:10.1007/s00466-013-0952-6
  • P.R. Budarapu, R. Gracie, S.P.A. Bordas, T. Rabczuk (2014) An adaptive multiscale method for quasi-static crack growth, Computational Mechanics, 53:1129-1148 doi:10.1016/j.commatsci.2014.08.054
  • M. Paggi, P. Wriggers (2011) A nonlocal cohesive zone model for finite thickness interfaces – Part I: Mathematical formulation and validation with molecular dynamics, Computational Materials Science, 50:1625-1633 doi:10.1016/j.commatsci.2010.12.024

Simulation of crack propagation at the molecular scale

Computational fluid dynamics
Development of staggered computational schemes to couple contact mechanics and computational fluid dynamics simulations for the characterization of fluid transport across rough surfaces in contact.

  • M. Paggi, Q.-C. He (2015) Evolution of the free volume between rough surfaces in contact, Wear, doi:10.1016/j.wear.2015.04.021
  • P. Cinat, M. Paggi (2015) Simulation of fluid flow across rough surfaces in contact. YIC GACM 2015 3rd ECCOMAS Young Investigators Conference, July 20–23, 2015, Aachen, Germany.

Stream lines of a fluid flow across an elastic rough surface in contact with a rigid half-plane


Due to the progress in materials science, innovative micro- and nano-structures can be manufactured in order to produce materials with superior mechanical, thermal and electric properties. However, their design and optimization is often left to empirical criteria, rather than being theoretically justified. The mission of the research unit MUSAM is to make a breakthrough in this multidisciplinary research by developing new multi-scale and multi-physics computational methods and non-conventional nondestructive experimental techniques. The key resource of this activity is the interaction with national and international companies, which greatly contributes to the identification of competitive design and of industrial solutions, as well as the close collaboration with a network of leading international research institutes and universities.

Expected results

The research output will regard the publication of scientific results in the top journals of physics, engineering and materials science, as well as in the proceedings of the most important international peer-reviewed thematic conferences. The research unit aims at having a strong scientific impact, which can be quantified by the number of citations obtained by the papers published and by the number of invited seminars delivered at international institutes by the members of the research unit. Another important output will concern the formation of Ph.D. candidates capable of exporting the scientific skills acquired at IMT not only in other academic groups, but also (and especially) into the industry, which represents the best way to disseminate the methodologies developed in the research unit to industrial practice.

Annual reports containing a summary of scientific achievements and educational activities of MUSAM:

Annual Report 2014
Annual Report 2015

Research facilities

MUSAM LAB - Ex Officina Aromataria Convento San Francesco (XIII Century), see also MUSAM-Lab

Opportunities for industrial collaborations (in Italian):
Brochure MUSAM-Lab
Please contact Dr. Claudia Borri (, responsible for the experimental activities.

  • Finite element (FEAP), Boundary element (BEM), Computational Fluid Dynamics (CFD), and Molecular Dynamics (LAMMPS) software
    Software for the implementation of user-defined subroutines to model complex physics and engineering problems with multiple scales and in multi-physics. Parallel computation facilities available on the servers Hewlett Packard 653745-421 Proliant DL585R07 (128 GB Ram, 4 processors AMD Opteron 6282 SE 2.60 GHz, 16 cores each) and Hewlett Packard DL560G8 (126 GB Ram, Intel Xeon 2x E5-4610v2 2.3 GHz, 64 GB).
  • 3D confocal-interferometric profilometer (LEICA, DCM 3D)
    Non-contact optical profilometer based on confocal and interferometric methods with resolution ranging from few nanometers up to several millimiters.
  • Scanning Electron Microscope (ZEISS, EVO MA15)
    SEM with maximum resolution of 3 nm and automated pressure regulation from 10 to 400 Pa to work with metallic and non-metallic samples without the need of metallization.
  • Micromechanical testing stage (DEBEN, 5000S)
    Tensile/compression stage for forces up to 5 kN specifically designed to allow real time observation of the microstructure evolution of materials within SEM
  • Universal testing machine with a thermostatic chamber (Zwick/Roell, Z010TH)
    Universal testing machine for tensile tests, compression tests and three-point bending tests on notched beams for fracture mechanics characterization. Two load cells of 1 kN and 10 kN are available. Testing can be made inside a thermostatic chamber in the temperature range from -30°C up to 250°C.
  • Thermocamera (FLIR, T640bx)
    IR thermocamera with 640x480 pixel of resolution for thermoelastic tests in the laboratory and for in-situ inspection of hot spots in photovoltaic modules and electric circuits.
  • Photocamera for electroluminesce tests (PCO, 1300 Solar)
    IR photocamera specific for carrying out electroluminescence tests in the laboratory.
  • System for 3D displacement correlation technique (Correlated Solutions, VIC3D)
    System for displacement and strain measurement using the displacement correlation technique in 3D, to be used together with the universal testing machine and with images taken using the scanning electron microscope.

Projects and funding


  • 2012-2017 – ERC Starting Grant 2012 "Multi-scale and multi-physics computational approach to design and durability of photovoltaic modules", granted by the European Research Council (1.483.980 Euro), Principal Investigator: Prof. M. Paggi.
  • 2012-2016 - FIRB Futuro in Ricerca 2010 "Structural mechanics models for renewable energy applications", granted by the Italian Ministry of Education, University and Research, MIUR (954,800 Euro), Principal Investigator: Prof. M. Paggi.


  • 2011-2012 - Vigoni Project 2010 "3D modelling of crack propagation in polycrystalline materials". The project, in collaboration with Prof. P. Wriggers, Leibniz University Hannover, Hannover, Germany, is granted by the Italian Ministry of Education, University and Research (MIUR), Ateneo Italo-Tedesco, and the Deutscher Akademischer Austausch Dienst (DAAD) (15,000 Euro), Principal Investigator: Prof. M. Paggi.


External Academic and Industry Collaborations
The research unit collaborates with several research centers, universities, and institutions around the world and in Italy, including:

Industrial collaborations and endorsements from industry:



  • EUROMECH Colloquium 575 Contact Mechanics and Coupled Problems in Surface Phenomena, March 30-April 2, 2015, IMT School for Advanced Studies Lucca.
  • GIMC-GMA 2016 Joint Conference of the Italian Group of Computational Mechanics and of the AIMETA Group on Materials, 27-29 June, 2016, IMT School for Advanced Studies Lucca.

Special sessions, minisymposia and workshops organized by RU members

  • Minisymposium "Fracture and Contact Mechanics for Interface Mechanical Problems", 11th World Congress on Computational Mechanics, 2014, Barcelona, Spain (Organized by M. Paggi, A. Carpinteri, P. Wriggers).
  • Special session "Numerical and Experimental Research on the Durability of Photovoltaic Modules", 1st International Symposium on Energy Challenges and Mechanics, 2014, Aberdeen, Scotland (Organized by J. Reinoso, M. Paggi, F. Haase).
  • Special session "Material Simulation for Energy Applications", 1st International Symposium on Energy Challenges and Mechanics, 2014, Aberdeen, Scotland (Organized by D. Antoun, L. De Lorenzis, M. Paggi, A. Piccolroaz).