Periodic Reporting for period 1 - NEWFRAC (New strategies for multifield fracture problems across scales in heterogeneous systems for Energy, Health and Transport)
Période du rapport: 2020-05-01 au 2022-04-30
A fast design-virtual testing and manufacturing cycle, automation, and data exchange in manufacturing technology requires highly efficient and reliable failure-predictive computational tools for an accurate prediction of fracture and damage phenomena associated with the initiation and propagation of cracks interacting with interfaces. These are critical for the structural integrity, reliability, and efficiency of different highly technological systems and components that are produced and used in a wide range of sectors, e.g. those related to the NEWFRAC project: i) Structural ceramics, and fiber-reinforced composites in the aeronautical, space and automotive industries; ii) Systems for renewable energy production such as photovoltaic modules, iii) Biomechanical systems for surgery.
The optimal exploitation of the capacities of such systems requires a deep knowledge of different fracture mechanisms affecting their integrity. The total losses due to fracture in the modern society can achieve a few percent of the gross economic product. These losses are at least partially evitable by a proper investment in research and application of new computational strategies for fracture prediction. However, the current modeling tools are insufficient for failure prediction in heterogeneous systems with high level of complexity, where cracks are interacting with bimaterial interfaces (initiating at/approaching/crossing/deflecting at/propagating along interfaces and kinking towards adjacent bulk) and in which multiple physical phenomena are coupled and occur at different length scales simultaneously.
NEWFRAC is the first coordinated initiative in EU aiming at the systematic progress in the failure prediction in heterogeneous systems through a novel computational framework by integrating two modern modelling strategies: the Coupled Criterion of Finite Fracture Mechanics and the Phase Field Models of Fracture, developed significantly in the last two decades.
The overarching objective of the NEWFRAC network is a high-level training of a new generation of creative, entrepreneurial, and innovative early-stage researchers (ESRs) through the development and engineering applications of these modelling strategies focusing on the prediction and analysis of multi-field fracture phenomena in specific heterogeneous engineering systems at different scales.
The main research objective of the NEWFRAC network is the development of a new modeling and simulation framework for the fracture mechanics optimization of high-level technological products involving heterogeneous systems (materials and structures), employed in engineering fields of strategic societal and scientific impact, ranging from renewable energy production systems to biological hard tissues.
The optimal exploitation of the capacities of such systems requires a deep knowledge of different fracture mechanisms affecting their integrity. The total losses due to fracture in the modern society can achieve a few percent of the gross economic product. These losses are at least partially evitable by a proper investment in research and application of new computational strategies for fracture prediction. However, the current modeling tools are insufficient for failure prediction in heterogeneous systems with high level of complexity, where cracks are interacting with bimaterial interfaces (initiating at/approaching/crossing/deflecting at/propagating along interfaces and kinking towards adjacent bulk) and in which multiple physical phenomena are coupled and occur at different length scales simultaneously.
NEWFRAC is the first coordinated initiative in EU aiming at the systematic progress in the failure prediction in heterogeneous systems through a novel computational framework by integrating two modern modelling strategies: the Coupled Criterion of Finite Fracture Mechanics and the Phase Field Models of Fracture, developed significantly in the last two decades.
The overarching objective of the NEWFRAC network is a high-level training of a new generation of creative, entrepreneurial, and innovative early-stage researchers (ESRs) through the development and engineering applications of these modelling strategies focusing on the prediction and analysis of multi-field fracture phenomena in specific heterogeneous engineering systems at different scales.
The main research objective of the NEWFRAC network is the development of a new modeling and simulation framework for the fracture mechanics optimization of high-level technological products involving heterogeneous systems (materials and structures), employed in engineering fields of strategic societal and scientific impact, ranging from renewable energy production systems to biological hard tissues.
The goals of the network, the development of innovative modeling strategies for fracture prediction and the training of the 13 recruited Early Stage Researchers (ESRs), who should become expert researchers ready to be incorporated as group-leaders in industrial and/or academic institutions, are being achieved by a unique combination of “hands-on” research training, non-academic placements and secondments, schools, workshops and courses on scientific and complementary transferable skills facilitated by the academic/non-academic composition of the network. During the period covered, the main network wide training events for our ESRs but also for external young researchers, in addition to local training courses offered by academic beneficiaries, have been: 1. Monthly Webinars, 2. NewFrac CORE School, 3. Phase Field Models of Fracture course, 4. GitLab course, 5. FEniCS day training, 6. NewFrac Workshop 1 - New Strategies in Computational Fracture Mechanics, 7. NewFrac PRO School, 8. NewFrac Workshop 2 – Expanding Horizons.
The most relevant scientific results obtained so far in the network are the following ones: - Application of Finite Fracture Mechanics at the micro-scale to bending tests of micro cantilever beams, - A humidity dose-cohesive zone model formulation to simulate new end-of-life recycling methods for photovoltaic laminates, - Analytical modeling of debonding mechanism for long and short bond lengths in direct shear tests accounting for residual strength, - Development of a new dynamic formulation of the coupled criterion of Finite Fracture Mechanics, - Development of a new phase field model for cracks under compression, - Development of a new phase field model for cracks in heterogeneous materials, - Study of a size-effect on the apparent tensile strength of brittle materials with spherical cavities.
The most relevant scientific results obtained so far in the network are the following ones: - Application of Finite Fracture Mechanics at the micro-scale to bending tests of micro cantilever beams, - A humidity dose-cohesive zone model formulation to simulate new end-of-life recycling methods for photovoltaic laminates, - Analytical modeling of debonding mechanism for long and short bond lengths in direct shear tests accounting for residual strength, - Development of a new dynamic formulation of the coupled criterion of Finite Fracture Mechanics, - Development of a new phase field model for cracks under compression, - Development of a new phase field model for cracks in heterogeneous materials, - Study of a size-effect on the apparent tensile strength of brittle materials with spherical cavities.
The high-level training offered by NewFrac to 13 Early Stage Researchers (ESRs), all of them PhD students, is focused on new strategies for prediction and analysis of multi field fracture phenomena in heterogeneous engineering systems at different scales. These ESRs are developing new failure predictive computational tools and apply them to relevant problems in strategic industrial sectors like Energy, Health and Transport. Their doctoral theses address most relevant questions of current interest in failure prediction in heterogeneous systems, that are generating high impact research outputs which go beyond the current state of the art in fracture modelling. To this aim, NewFrac integrates two new strategies for computational fracture modelling: Finite Fracture Mechanics and a variational approach to fracture referred to as Phase Field, and solves wide ranging interconnected fundamental issues of fracture modelling like:
1. Fragmentation and dynamic crack propagation.
2. Toughening composites by micro and meso structural optimization.
3. Simultaneous crack initiation and propagation interacting with interfaces.
4. Fracture prediction in human long bones.
5. Failure mechanisms of ultra-thin ply laminates.
6. Innovative solutions to the fracture of injection molded short fiber reinforced polymer composites.
7. Reinforcement of externally strengthened curved beams by fiber reinforced polymer composites in civil engineering.
NewFrac network guarantees the attendance of ESRs to all network wide training activities, and favours their training through interdisciplinary and intersectoral research, mobility, and exposure to industry, aiming at their transfer to industry after the NewFrac. It is expected that these ESRs will become experts in fracture prediction in heterogeneous systems and will contribute to reduce the innovation gap by enhancing two ways academia industry transfer of knowledge.
1. Fragmentation and dynamic crack propagation.
2. Toughening composites by micro and meso structural optimization.
3. Simultaneous crack initiation and propagation interacting with interfaces.
4. Fracture prediction in human long bones.
5. Failure mechanisms of ultra-thin ply laminates.
6. Innovative solutions to the fracture of injection molded short fiber reinforced polymer composites.
7. Reinforcement of externally strengthened curved beams by fiber reinforced polymer composites in civil engineering.
NewFrac network guarantees the attendance of ESRs to all network wide training activities, and favours their training through interdisciplinary and intersectoral research, mobility, and exposure to industry, aiming at their transfer to industry after the NewFrac. It is expected that these ESRs will become experts in fracture prediction in heterogeneous systems and will contribute to reduce the innovation gap by enhancing two ways academia industry transfer of knowledge.