2020 Fiscal Year Research-status Report
Theoretical and numerical analysis for a phase-field model describing the crack growth phenomenon
| Project/Area Number |
19K14605
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
GAO Yueyuan 国立研究開発法人産業技術総合研究所, 材料・化学領域, 産総研特別研究員 (80807793)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | Crack growth phenomenon / Phase-field model / Data science / Numerical analysis |
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| Outline of Annual Research Achievements |
We study the crack growth phenomenon by means of a phase-field model. The model contains 2 equations and one equation involves the positive-part function. The positive-part function is due to the irreversibility of the crack growth phenomenon. After having tested that our codes can give stable simulation results, we started to investigate the properties of the material, especially the J-integral and the fracture toughness by numerical analysis and data science techniques.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In order to obtain the correct value the J-integral, we have checked and discussed the physical meaning of the parameters in the phase-field model. Then we start to combine data science techniques to study the fracture toughness. We change the fracture toughness at a certain region to consider inhomogeneous materials. And we check the relation between the fracture toughness and the J-integral.
We performed simulations to validate the fact that increasing the fracture toughness at a certain region indeed prevents the crack to propagate, and thus gives larger value of the J-integral, which corresponds to a tougher material. In the study, we have tried various type of inhomogeneity, both in deterministic and stochastic cases and that leads us towards the study of the design of materials.
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| Strategy for Future Research Activity |
The questions that we are now investigating on the design of materials are
1) Given a path of a crack, if we assume some properties on the material, such as the boundary condition and the homogeneity, can we inversely estimate the parameters of the fracture toughness from the phase-field model.
2) Based on the parameter estimation, can we design the structure of the material so that it will have larger toughness.
In the phase-field model, there appears to be large contrast in the orders of the parameters. A challenging problem to be tackled at the first place is that can parameter estimation method identify the parameters to a certain accuracy. The method that we have been applying is called SINDy.
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| Causes of Carryover |
The project will be carried on by continuing the numerical analysis and by the interactions and discussions with collaborators. Therefore, during the next fiscal year, one part of the funding will be used for purchasing software as Matlab and some books, and the other part will be used for business trips of scientific visits.
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Research Products
(1 results)
