Damage and Rupture (ENR)
This OR focuses its research efforts on theoretical modeling and numerical simulation of damage and fracture phenomena in brittle, ductile and architectural materials. It also develops experiments in order to validate and identify theoretical and numerical models.
The 3 main themes of the Research Operation (R.O.) are presented below:
- Ductile fracture
- Brittle fracture
- Study of architectural materials
Fracture of architectural materials
A homogenization model to describe the behavior of materials with periodic microstructure has been developed. The influence of the second gradient has been incorporated in the establishment of the behavioral laws of architectural materials. The natural extension of this work is to study the influence of the second gradient on damage and failure. This study relies on the development of tests performed on printed structures in order to fully understand the failure mechanisms, on the basis of which the failure model should be established and adjusted.
Study of the behavior of polymeric materials from 3D printing to failure.
In this work, we study numerically and experimentally the rupture of polymers from 3D printing. These materials have characteristics specific to polymers (viscosity, temperature sensitivity) and to the 3D printing process used (anisotropy) which make their study more complex. They also benefit from the great freedom of form offered by 3D printing, which can be used to design new materials and new experimental devices. A thesis is in progress on this subject (Massinissa Hider, 2019-2022) with the objective of modeling the behavior of these materials up to their complete rupture.
Numerical simulations with a shear specimen (damage variable)
Fracture and damage of brittle materials
The LSPM has long been developing models of damage and failure of brittle materials. Non-local models have been successively used to predict the initiation and propagation of cracks in ceramic materials under thermal loading, in ceramic matrix composites, in Plexiglas etc. Based on these results, efforts are pursued to complete and improve these models. In particular, the numerical models of 3D fracture are extended in order to better meet the industrial requirements, especially concerning the failure of composite materials. Failure mechanisms induced by diffusion phenomena (thermal loading, drying failure, etc.) will also be studied and modeled in a unique global framework. In addition, efforts are undertaken to develop experimental observation of fracture based on image correlation techniques.
Numerical implementation of the coupled failure criterion
Cracking in brittle materials is a traditional research topic of the O.R. ENR. The recent development in this field is the numerical implementation of the coupled failure criterion for damaged materials. Damage, initiation and propagation of multiple cracks can be considered in a single theoretical and numerical framework.
Damage field.
Jia Li et al. International Journal of Structures and Solids, 2019, 165, 93-103
Chemin des fissures dans un composite matrice-granulats.
Jia Li et al. International Journal of Structures and Solids, 2019, 165, 93-103
Failure and damage of ductile materials
Within the framework of academic or industrial projects mainly led by other ORs, studies on metallic materials have been initiated, in particular on the damage and fracture of alloys with harmonic microstructure (Harmonic Structures: HS), in collaboration with the OR 2MP. The goal of this work is to model the failure of HS materials at the mesoscopic scale and to simulate the complete process of plasticization – damage – failure. To do so, we focus our efforts on the establishment of a damage model able to describe the complex mechanisms of material deterioration, the damage – failure transition and to solve all the numerical problems induced by this highly non-linear process.
Modeling the behavior and damage of materials with harmonic microstructure
This is one of the key research topics of MECAMETA and is the subject of collaboration between several LSPM teams. Our task is to establish theoretical and numerical models to predict mechanical properties from the microstructures of metals. To do this, the multi-scale concept has been used in the description of the deformation and damage of materials.
