THE FINITE ELEMENT CODE NOSA FOR NONLINEAR STRUCTURAL ANALYSIS

Material models ELASTICITY: static and dynamic analysis COMPOSITE: shell and beam elements have layers with different mechanical and thermal properties ELASTO-PLASTICITY: static and dynamic analysis MASONRY-LIKE: static and dynamic analysis HEAT TRANSFER

Istituto di Scienza e Tecnologie dell’Informazione “A. Faedo”

Element library of the NOSA code

Structural type Element identifier number

Interpolating functions

Remarks

3D element 1 quadratic 20 nodes isoparametric element

Plane stress element

2 quadratic 8 nodes isoparametric element

Plane strain element

3 quadratic 8 nodes isoparametric element

Axisymmetric element

4 quadratic 8 nodes isoparametric element

Thin shell element

5 Linear for displacements, quadratic for rotations

8 nodes isoparametric element

Structural type Element identifier number

Interpolating functions

Remarks

Plane strain element

6 linear 4 nodes isoparametric element

Axisymmetric element

7 linear 4 nodes isoparametric element

3D element 8 linear 8 nodes isoparametric element

Straight beam element

9 linear 2 nodes isoparametric element

Thick shell element

10 Linear for displacements and rotations

4 nodes isoparametric element

Structural type Element identifier number

Interpolating functions

Remarks

Plane heat transfer element

11 quadratic 8 nodes isoparametric element

Plane heat transfer element

12 linear 4 nodes isoparametric element

Axisymmetric heat transfer element

13 quadratic 8 nodes isoparametric element

Axisymmetric heat transfer element

14 linear 4 nodes isoparametric element

3D heat transfer element

15 linear 8 nodes isoparametric element

Flow-chart for NOSA (nonlinear static analysis)

Static and dynamic analysis Limit analysis Thermo-mechanical analysis of masonry structures subjected to thermal variations Modelling of strengthening operations (fitting of metallic Beams and rings, retaining structures, etc.)

THE FINITE ELEMENT CODE NOSA FOR THE STRUCTURAL ANALYSIS OF HISTORIC MASONRY CONSTRUCTIONS

NOSA has been successfully applied to the analysis of some buildings of historical and architectural interest:

The baptistery of the Volterra cathedral (1995)

The finite element mesh

The stress field in the dome has been calculated with the aim of assessing the effectiveness of the existing metallic rings.

The Medici Arsenal, Pisa (1996)

The arches of the Arsenal

The study is aimed at determining the static behaviour of the structure dating back to the XIII century and constituted by twelve series of arches. In particular, some strengthening interventions have been modelled and compared in order to assess their effects on the static safety and seismic resistence of the construction.

The Goldoni theatre, Livorno (1998)

The static behaviour of the scenic arch has been assessed.

The S. Nicolò cathedral, Noto (1998)

The longitudinal wall

The static behaviour of the right longitudinal wall of the nave has been analysed with the aim of determining the effects of differential settling of the pillars.

The Buti bell tower (2004)

Crack distribution in the tower

A static analysis of the bell tower subjected to its own weight and a horizontal load simulating a seismic action has been conducted with the aim of determining the origins of the cracks.

The church of San Pietro in Vinculisa, Pisa (2003)

Crack distribution in a longitudinal wall

The right longitudinal wall of the wall has been analysied with the aim of assessing the effect of differential settlings of the pillar on the stress field and crack distribution .

The church of Santa Maria Maddalena, Morano Calabro (2004-2005)

Crack distribution in the dome

A static analysis of the dome and the drum has been conducted with the aim of assessing the effects of both differential settlings of the drum and a horizontal load on the stress field and crack distribution in the dome.

The church of San Ponziano, Lucca (2005, 2007)

Finite element discretization of the vault

Static and dynamic analyses of the cross vault overlooking the altar have been conducted by taking the presence of the metallic tie-rods into account.

The church of Santa Maria della Roccella, Roccelletta Borgia (2009)

Dynamic analysis of the church

The study aims at analyse the sesimic vulnerability of the structure and take into account the regulations provided by the Ministry of Cultural Heritage in 2007 concerning the assessment and reduction of the seismic risk of the historical buildings.

The Rognosa tower, San Gimignano (2008-2011)

The study concerns the static behaviour and the seismic vulnerability of the Rognosa tower, added to the Unesco World Heritage List in 1990. The behaviour of the tower subjected to its own weight and an accelerogram recorded during a real earthquake, is investigated.

The tower of the Hours, Lucca (2010)

Finite element discretization of the tower

The analysis aims at assessing the dynamic beaviour of the tower in the presence of time-dependent loads modelling seismic actions.

- The finite element code NOSA allows: - to determine the static and dynamic behaviour of masonry buildings

- to model strengthening interventions and assess their effectiveness before implementation

Therefore, NOSA can be used in the field of maintenance and safeguarding of the national architectural heritage to assess the safety of artistically important masonry buildings and to optimise potential maintenance and strengthening operations in terms of architectural impact and static effectiveness.

COMES-NOSA is a freeware version of NOSA for the nonlinear static analysis of masonry buildings http://www.isti.cnr.it/research/unit.php?unit=MMS&section=software