Strain Measurements During Structural Conservation Treatment and the Long-term Monitoring of a 17th-century Dutch Panel Painting

No abstract available

Strain Measurements During Structural Conservation Treatment and the Long-term Monitoring of a 17th-century Dutch Panel Painting

No abstract available

Learning from Objects: the use of advanced numerical methods to exploit a complete set of information from experimental data, for the Mona Lisa’s Digital-Twin

International audienceThe approach to wooden artefacts of historical importance, and panel paintings in particular, is a task that requires a multidisciplinary approach based on experimental observation of the artwork and advanced techniques to make these data actually useful for the knowledge and preservation of the object. This study illustrates how a series of scientific observations and instrumental analyses can be used to construct a numerical simulation that allows a deeper understanding of the physical structure and behaviour of the object itself, namely to construct a hygro-mechanical predictive model (a “Digital-Twin”) of Leonardo da Vinci's Mona Lisa panel. Based on specific request from the Louvre Museum, a group of experts with different and complementary skills cooperated and are still cooperating to construct a complete set of experimental observation and non-invasive tests; so, the integration of the collected data made the construction possible of the panel’s Digital-Twin. This paper also specifically examines how the Digital-Twin can be used to compare two framing conditions of the panel; although the two experimental configurations are not inherently comparable, the comparison is made possible by the introduction of a technique of projection of the fields obtained as results of the two analyses, named the Projected Model Comparison (PMC), which has been developed specifically for this research

Suivi du comportement mécanique d’une peinture sur bois soumise à des variations d’hygrométrie

International audienceCe travail collaboratif (présenté lors de la précédente journée) regroupe le musée Fabre, des restaurateurs mobilier et couche picturale ainsi que des chercheurs du GESAAF (Université de Florence), de l’institut PPRIME (Université de Poitiers) et du LMGC (Université de Montpellier). Le but de cette étude est la caractérisation du comportement mécanique d’un panneau de bois peint du patrimoine soumis à des variations d’environnement hygrothermique contrôlées. Dans la perspective d’une exposition prévue en 2018 et destinée à destinée à faire connaître les pratiques de la restauration des œuvres d’art au public, la communication sur cette interaction entre acteurs patrimoniaux et académique fait l’objet d’une attention particulière

The Mona Lisa Project: an update on the progress of measurement, monitoring, modelisation and simulation

International audienc

Studies for the Mona Lisa conservation

International audienceSince 2004, the wooden panel of the “Mona Lisa” painting by Leonardo da Vinci has been studied by an internationalresearch group of scientists [1,2] and several experimental campaigns have been carried out to understand itscharacteristics and provide information for the Artwork's conservation [3]. Among these, the implementation of its"digital twin" is here presented as a fundamental step for its conservation. Indeed, this digital twin is providing a deeperunderstanding of the mechanical characteristics of the panel, and after it has been accurately calibrated, it will providethe means for evaluating the stress states which the Artwork undergoes when the surrounding climatic conditions vary.Moreover, it will allow to evaluate in a non-invasive way the effects produced on the Artwork by any changes of itsframing conditions, including the internal stresses or the external forces that it can bear without damage.The implementation of the digital twin, through a Nelder-Mead optimization scheme, starts from the definition of theshape of the Artwork, through optical methods [4], and the identification of the boundary conditions, through anexperimental campaign based on the use of a film sensitive to pressure [5]. During the whole year, while exhibited inthe conditioned display case, the panel continuously tends to deform, due to the slight variations in the surroundingenvironment. Its mechanical behaviour is automatically monitored and recorded every 30 minutes by an ad hocequipment placed close to its back face: four miniature load cells (located at the four corners) measure the forces pressingit against the frame, and three displacement transducers measure its deflection at mid height. Finally, a method is heredescribed to compare two different framing conditions, through the numerical computation of point-by-point stress anddeformation differences, in order to provide information for optimizing settings and constraints to Conservators

Studies for the Mona Lisa conservation

International audienceSince 2004, the wooden panel of the “Mona Lisa” painting by Leonardo da Vinci has been studied by an internationalresearch group of scientists [1,2] and several experimental campaigns have been carried out to understand itscharacteristics and provide information for the Artwork's conservation [3]. Among these, the implementation of its"digital twin" is here presented as a fundamental step for its conservation. Indeed, this digital twin is providing a deeperunderstanding of the mechanical characteristics of the panel, and after it has been accurately calibrated, it will providethe means for evaluating the stress states which the Artwork undergoes when the surrounding climatic conditions vary.Moreover, it will allow to evaluate in a non-invasive way the effects produced on the Artwork by any changes of itsframing conditions, including the internal stresses or the external forces that it can bear without damage.The implementation of the digital twin, through a Nelder-Mead optimization scheme, starts from the definition of theshape of the Artwork, through optical methods [4], and the identification of the boundary conditions, through anexperimental campaign based on the use of a film sensitive to pressure [5]. During the whole year, while exhibited inthe conditioned display case, the panel continuously tends to deform, due to the slight variations in the surroundingenvironment. Its mechanical behaviour is automatically monitored and recorded every 30 minutes by an ad hocequipment placed close to its back face: four miniature load cells (located at the four corners) measure the forces pressingit against the frame, and three displacement transducers measure its deflection at mid height. Finally, a method is heredescribed to compare two different framing conditions, through the numerical computation of point-by-point stress anddeformation differences, in order to provide information for optimizing settings and constraints to Conservators

Mona Lisa’s digital twin: identifying the mechanical properties of the panel combining experimental data and advanced finite-element modelling

International audienceSince 2004, the “Mona Lisa” painting by Leonardo da Vinci has been studied by an international research group of wood scientists and several experimental campaigns have been carried out to understand its characteristics and provide indications for its conservation. Based on the collected data, a numerical model of the wooden panel has been developed to simulate the mechanical interaction with the framing system. The main objective of this modelling work, described in this paper, is to extract as much information as possible from the experimental tests carried out and, thus, reach a sufficient level of scientific knowledge of the mechanical properties of the panel to build a predictive model. It will be used to predict the effect of modified boundary conditions and as a tool of preventive conservation

Studies for the Mona Lisa conservation: The implementation of its panel's Digital-Twin

International audienceSince 2004, the wooden panel of the “Mona Lisa” painting by Leonardo da Vinci has been studied by an international research group of scientists [1,2] and several experimental campaigns have been carried out to understand its characteristics and provide information for the Artwork's conservation [3]. Among these, the implementation of its "digital twin" is here presented as a fundamental step for its conservation. Indeed, this digital twin is providing a deeper understanding of the mechanical characteristics of the panel, and after it has been accurately calibrated, it will provide the means for evaluating the stress states which the Artwork undergoes when the surrounding climatic conditions vary. Moreover, it will allow to evaluate in a non-invasive way the effects produced on the Artwork by any changes of its framing conditions, including the internal stresses or the external forces that it can bear without damage. The implementation of the digital twin, through a Nelder-Mead optimization scheme, starts from the definition of the shape of the Artwork, through optical methods [4], and the identification of the boundary conditions, through an experimental campaign based on the use of a film sensitive to pressure [5]. During the whole year, while exhibited in the conditioned display case, the panel continuously tends to deform, due to the slight variations in the surrounding environment. Its mechanical behaviour is automatically monitored and recorded every 30 minutes by an ad hoc equipment placed close to its back face: four miniature load cells (located at the four corners) measure the forces pressing it against the frame, and three displacement transducers measure its deflection at mid height. Finally, a method is here described to compare two different framing conditions, through the numerical computation of point-by-point stress and deformation differences, in order to provide information for optimizing settings and constraints to Conservators