1. Dipartimento di Ingegneria Civile – Università degli Studi di Salerno
Dottorato di Ricerca in Ingegneria delle Strutture e del recupero edilizio e urbano - IX ciclo N. S. Presentazione del lavoro di tesi Analisi non lineare di pareti murarie sotto azioni orizzontali: modellazione a telaio equivalente Fisciano, 6 Maggio 2011
Dottorando: Ing. Riccardo Sabatino
Tutor: Prof. Vincenzo Piluso
Co-Tutor: Prof. Gianvittorio Rizzano

2. PhD Dissertation Talk – Fisciano, 6th May 2011
All exact science is dominated by the idea of approximation
Bertrand Russell
Science is organized knowledge
Herbert Spencer
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

3. PhD Dissertation Talk – Fisciano, 6th May 2011
Outline
Chapter 1: Introduction
Chapter 2: FEM modelling
Chapter 3: Masonry Buildings Modelling Strategies
Chapter 4: Mechanical Behaviour of masonry panels
Chapter 5: Matrix Analysis of structures
Chapter 6: The FREMA code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

4. PhD Dissertation Talk – Fisciano, 6th May 2011
Outline
Chapter 1: Introduction
Chapter 2: FEM modelling
Chapter 3: Masonry Buildings Modelling Strategies
Chapter 4: Mechanical Behaviour of masonry panels
Chapter 5: Matrix Analysis of structures
Chapter 6: The FREMA code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

5. PhD Dissertation Talk – Fisciano, 6th May 2011
Introduction
Fresco found in Rekhamara’s Tomb (1500 b.C. – Egypt)
First Stone Dwellings (8350 b.C. – Jericho, Tell-es-Sultan)
Djoser Pyramid (2600 b.C. – Egypt)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

6. PhD Dissertation Talk – Fisciano, 6th May 2011
Introduction
Performance-based Earthquake Engineering  Non-linear static procedures (NLP)
Non-linear Static Analysis
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

7. PhD Dissertation Talk – Fisciano, 6th May 2011
Introduction
Strategies for Modelling Masonry Buildings
FEM models VS
Simplified models
√ Very accurate prediction
√ Any kind of structure may be analysed
X Time-consuming
X Amount of input data
X High Analytical Skills required
√ Suitable for professional purposes
√ Quick analyses
X Regular geometry needed
X Simplifications need to evaluated
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

8. PhD Dissertation Talk – Fisciano, 6th May 2011
Outline
Chapter 1: Introduction
Chapter 2: FEM modelling
Chapter 3: Masonry Buildings Modelling Strategies
Chapter 4: Mechanical Behaviour of masonry panels
Chapter 5: Matrix Analysis of structures
Chapter 6: The FREMA code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

9. PhD Dissertation Talk – Fisciano, 6th May 2011
Accurate Modelling: mesoscale model
Blocks are modelled using continuum elements, while mortar and brick-mortar interfaces are modelled by means of nonlinear interface elements (Lourenço & Rots, 1996).
Solid and interface elements account for large displacements, while only interface elements represent cracks in mortar and bricks.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 9

10. PhD Dissertation Talk – Fisciano, 6th May 2011
A novel 2D nonlinear interface element
Material model
Multi-surface
nonassociated plasticity
Elastic response
Yield functions F1 - F2
Elastic stiffness
Plastic potentials Q1 - Q2
Mortar joints
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 10

11. PhD Dissertation Talk – Fisciano, 6th May 2011
A novel 2D nonlinear interface element
Material model
Nonassociated plasticity
Elastic response
Yield function F1
Elastic stiffness
penalty factor
Brick interface
Plastic potential Q1
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 11

12. PhD Dissertation Talk – Fisciano, 6th May 2011
A novel 2D nonlinear interface element
Material properties s
sC - compressive strength s st
st - tensile strength
GC - crushing energy
Gf,I - mode I
fracture energy
Gf,I s s s uz sc t s Gc
C - cohesion
s<0 t s uz
Gf,II - mode II
fracture energy c
stanf t
Gf,II
f - friction angle s
ux(y)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 12

13. A novel 2D nonlinear interface element
PhD Dissertation Talk – Fisciano, 6th May 2011
A novel 2D nonlinear interface element
Work-softening plasticity
Evolution of the material parameters
Evolution of the surfaces
with
Wpl1 - plastic work related to F1
Wpl2 - plastic work related to F2
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 13

14. PhD Dissertation Talk – Fisciano, 6th May 2011 shear cyclic behaviour
A novel 2D nonlinear interface element
Traction deformation response
shear
tension
shear cyclic behaviour
tension-compression cyclic behaviour
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 14

15. PhD Dissertation Talk – Fisciano, 6th May 2011
In-plane behaviour
Vermeltfoort AT, Raijmakers TMJ (1993)
mortar interface
brick interface
pv=0.3 MPa
J4D
J5D
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 15

16. PhD Dissertation Talk – Fisciano, 6th May 2011
In-plane behaviour
Vermeltfoort AT, Raijmakers TMJ (1993)
Wpl1
Wpl2
Wpl1
Wpl1
Wpl1
pv=0.3 MPa
pv=2.12 MPa
pv=0.3 MPa
J4D
J5D
dynamic analysis
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 16

17. PhD Dissertation Talk – Fisciano, 6th May 2011
In-plane behaviour
Mesh assessment
Mesh refinement
Number of integration points over the interface
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 17

18. PhD Dissertation Talk – Fisciano, 6th May 2011
In-plane behaviour
Vermeltfoort AT, Raijmakers TMJ (1993)
Wpl1
Wpl2
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling 18

19. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting: Influence of spandrels
Numerical Modelling (STRAUS7): 144 panels
Panels have been obtained by assembling a reference module whose geometry (piers, spandrels) has been properly varied.
The parameter l, ratio between the shear stiffness of piers and spandrels, has been used to take into account the panels geometry.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

20. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting: Influence of spandrels
Panels have been modelled by assuming two limit schemes: infinite stiffness spandrels and “unreinforced” spandrels.
The parameter represents the expected improvement of relative shear strength achievable by means of spandrels retrofitting.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

21. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting: Influence of spandrels
The comparison shows a significant improvement in the field l<1.5, i.e. for weak spandrels.
In such field the average strength improvement can be estimated as:
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

22. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting
Then the panels 1-1 and 4-4 have been extensively investigated by considering the retrofitting approach suggested in Italian Building Code.
For each panel, the weak spandrel (l=0.70) and the strong spandrel (l=5.35) schemes have been analysed.
Three different kinds of reinforcements have been taken into account:
Injection Grouts;
Reinforced plasters;
Ring beams / Jack Arch.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

23. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting
The shear resistance of the panels has been evaluated by means of a non-linear static analysis. Both the unreinforced and the reinforced wall have been analyzed.
The improvement deriving from the reinforcement has been summarized into the parameter
where T is the reinforced wall resistance, Tnc the unreinforced wall resistance.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

24. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

25. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting: Wall 1-1
For weak spandrels walls, the spandrel improvement gives the same results of injection grouts/reinforced plasters.
For strong spandrels walls, best improvements have been achieved with injection grouts/reinforced plasters.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

26. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting: Wall 4-4
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

27. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting
The expected improvement gets the same order of magnitude of data available in literature
[Modena et al.]
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

28. PhD Dissertation Talk – Fisciano, 6th May 2011
Retrofitting: Parete 4-4
For the wall 4-4, further numerical simulations have been performed, by assuming the reinforcement (reinforced plaster/injection ) applied to 1 to 4 storeys.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

29. PhD Dissertation Talk – Fisciano, 6th May 2011
Outline
Chapter 1: Introduction
Chapter 2: FEM modelling
Chapter 3: Masonry Buildings Modelling Strategies
Chapter 4: Mechanical Behaviour of masonry panels
Chapter 5: Matrix Analysis of structures
Chapter 6: The FREMA code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

30. PhD Dissertation Talk – Fisciano, 6th May 2011
Simplified Models
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

31. PhD Dissertation Talk – Fisciano, 6th May 2011
Outline
Chapter 1: Introduction
Chapter 2: FEM modelling
Chapter 3: Masonry Buildings Modelling Strategies
Chapter 4: Mechanical Behaviour of masonry panels
Chapter 5: Matrix Analysis of structures
Chapter 6: The FREMA code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

32. PhD Dissertation Talk – Fisciano, 6th May 2011
Description of the model
Equivalent Frame Model
Spandrels
Piers (Heff after Dolce, 1991)
Main features
1. Displacement Control approach  NLP
2. Global and local equilibrium
3. Spread plasticity approach
4. Quick Analysis and Easy Post-processing
Rigid Offsets
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

33. PhD Dissertation Talk – Fisciano, 6th May 2011
Piers - Constitutive Laws
Generalized Uniaxial Compressive Stress-Strain Relationship
A=2, B=-1, C=2 [Hendry, 1998]
A=6.4, B=-5.4, C=1.17 [Turnšek-Čačovič, 1980]
[After Tomaževič, 1999]
 Accurate Moment-Curvature
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

34. PhD Dissertation Talk – Fisciano, 6th May 2011
Piers - Flexural Behaviour
Cross-section Equilibrium Equations
x normalised neutral axis
normalised axial force
m normalised bending moment
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

35. Moment-Curvature relationship workflow
PhD Dissertation Talk – Fisciano, 6th May 2011
Moment-Curvature relationship workflow
D, t, c, n cu NO
c < cu
END
YES
ccr x M
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

36. PhD Dissertation Talk – Fisciano, 6th May 2011
Piers - Shear Behaviour
Experimental Behaviour
Model
[After Anthoine, Magenes, Magonette, 1994]
Ultimate drift du = 0.4% Heff
[Italian Building Code]
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

37. PhD Dissertation Talk – Fisciano, 6th May 2011
Piers - Shear Behaviour
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

38. Shear-strain relationship workflow
PhD Dissertation Talk – Fisciano, 6th May 2011
Shear-strain relationship workflow
min Vu
gi=Vi/Ki
gel=Vu/Kel
YES
gi < gel
Ki+1=Kel NO
Ki+1=Ki *Vu/Vi
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

39. Shear-strain relationship workflow
PhD Dissertation Talk – Fisciano, 6th May 2011
Shear-strain relationship workflow
Collapse condition when the desired value of drift (set by the user) is attained
(Italian Building Code suggets d = for shear collapse)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

40. PhD Dissertation Talk – Fisciano, 6th May 2011
Spandrels - Shear Behaviour
Experimental Behaviour
Model
Residual Strength a = 0.25
[Magenes and Della Fontana, 1998]
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

41. PhD Dissertation Talk – Fisciano, 6th May 2011
Spandrels - Flexural Behaviour
Experimental Behaviour
Model
[After Calderoni et al., 2008]
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

42. PhD Dissertation Talk – Fisciano, 6th May 2011
Spandrels - Flexural Behaviour
Proposed formulations for Mu – [Italian Building Code, 2008]
Stress-block approach (same equation of piers)
2. If no tensile-resistant element is present  Mu=0
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

43. PhD Dissertation Talk – Fisciano, 6th May 2011
Spandrels - Flexural Behaviour
Proposed formulations for Mu [Schubert & Weschke, 1986] a)
Take into account an “equivalent strut” provided with a tensile strength ftu
ftu is the minimum between two collapse mechanisms:
a) bricks failure
b) bed joints failure b)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

44. PhD Dissertation Talk – Fisciano, 6th May 2011
Spandrels - Flexural Behaviour
Spandrels M-N Limit Domain [Cattari and Lagomarsino, 2008]
Constitutive Law
Improvement of rocking resistance, also with low (or zero) values of N.
h = ratio between tensile strength ftu and compressive strength
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

45. PhD Dissertation Talk – Fisciano, 6th May 2011
Outline
Chapter 1: Introduction
Chapter 2: FEM modelling
Chapter 3: Masonry Buildings Modelling Strategies
Chapter 4: Mechanical Behaviour of masonry panels
Chapter 5: Matrix Analysis of structures
Chapter 6: The FREMA code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

46. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

47. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

48. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Masonry Panels – Anthoine, Magonette and Magenes (1998)
Cross-Section: 100 x 25 cm2
Low panel high: 135 cm
High panel high: 200 cm
Normal Load: 150 kN
Low Panel
High Panel
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

49. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Pavia Door Wall – Calvi and Magenes (1994)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

50. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Pavia Door Wall – Calvi and Magenes (1994)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

51. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Pavia Door Wall – Calvi and Magenes (1994)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

52. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Catania Project - Investigation on the seismic response of two masonry buildings (2000)
“Via Martoglio” 2D Wall
Equivalent Frame model: 128 elements, 81 nodes, 219 DOF
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

53. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
“Via Martoglio” 2D Wall
Model 1: Masonry, NO R.C. Ring Beams
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

54. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
“Via Martoglio” 2D Wall
Model 2: Masonry, Elastic R.C. Ring Beams (E=20,000 MPa)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

55. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
“Via Martoglio” 2D Wall
Model 3: Masonry, Elastic R.C. Ring Beams (E=4,000 MPa)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

56. PhD Dissertation Talk – Fisciano, 6th May 2011
Preliminary validation of the model
Catania Project - Investigation on the seismic response of two masonry buildings (2000)
“Via Verdi” Building
Wall 1
Wall 2
Wall 3
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

57. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
“Via Verdi” – Wall 1
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

58. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
“Via Verdi” – Wall 2
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

59. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
“Via Verdi” – Wall 3
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

60. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Mallardo et al. (2008) – Palazzo Renata di Francia
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

61. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Mallardo et al. (2008)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

62. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Salonikios et al. (2003)
Two-storey, 7-bay masonry wall
Two lateral load distributions considered:
Uniform (ACC)
F= {1.00; 0.59}
Inverse Triangular (LOAD)
F= {1.00; 1.19}
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

63. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Salonikios et al. (2003) – 7B_Uniform
Discrete FEM model
Proposed Model
SAP 2000
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

64. PhD Dissertation Talk – Fisciano, 6th May 2011
The FREMA Code
Salonikios et al. (2003) – 7B_Inverse Triangular
Discrete FEM model
Proposed Model
SAP 2000
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

65. PhD Dissertation Talk – Fisciano, 6th May 2011
Mesh Refinement
Salonikios et al. (2003)
b=Log(Nc/Dx)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

66. PhD Dissertation Talk – Fisciano, 6th May 2011
Mesh Refinement
Salonikios et al. (2003) – 7B_Inverse Triangular
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

67. PhD Dissertation Talk – Fisciano, 6th May 2011
Mesh Refinement
Salonikios et al. (2003) – 7B_Uniform
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

68. PhD Dissertation Talk – Fisciano, 6th May 2011
Time-cost Analysis
Salonikios et al. (2003)
b=Log(Nc/Dx)
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

69. PhD Dissertation Talk – Fisciano, 6th May 2011
Time-cost Analysis
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

70. PhD Dissertation Talk – Fisciano, 6th May 2011
Conclusions
This dissertation deals with the seismic behaviour of masonry structures;
The first part of the work is aimed at understanding the potentialities of very accurate FEM model in predicting masonry panels seismic response; the panels simulated by means of ADAPTIC showed a very good prediction of the experimental results, both in terms of force-displacement curve and in terms of cracks path.
A further application of simplified (homogeneous) FEM models has been performed on masonry panels, aiming at evaluating the influence of spandrels reinforcement on the overall resistance; in the same application some reinforcement techniques have been applied considering the Italian Building Code approach;
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

71. PhD Dissertation Talk – Fisciano, 6th May 2011
Conclusions
In the second part of the dissertation, a novel equivalent frame model has been developed. The main features of the model have been discussed, by highlighting the main features of the proposed model (displacement control approach, accurate moment-curvature for piers behaviour, spandrels behaviour);
A validation and application of the model has been carried out  comparison with experimental tests and accurate numerical simulations
The comparison showed a good agreement between the proposed model and both experimental and numerical results, showing that FREMA code is a reliable tool for performing the non-linear static analysis of masonry panels.
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

72. PhD Dissertation Talk – Fisciano, 6th May 2011
Thank you very much!
R. Sabatino – Non-linear analysis of masonry walls under horizontal loads: equivalent frame modelling

73. Dipartimento di Ingegneria Civile – Università degli Studi di Salerno
Dottorato di Ricerca in Ingegneria delle Strutture e del recupero edilizio e urbano - IX ciclo N. S. Presentazione del lavoro di tesi Analisi non lineare di pareti murarie sotto azioni orizzontali: modellazione a telaio equivalente Fisciano, 6 Maggio 2011
Dottorando: Ing. Riccardo Sabatino
Tutor: Prof. Vincenzo Piluso
Co-Tutor: Prof. Gianvittorio Rizzano