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Reference : UMR7636-FREAUG-007
Workplace : PARIS 05
Date of publication : Wednesday, January 09, 2019
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 February 2019
Proportion of work : Full time
Remuneration : 2530
Desired level of education : PhD
Experience required : Indifferent
Work together with project leader to define the scope of research activities in terms of objectives
Develop and implement a work plan
Investigate models and approaches to test and develop them
Analyze and interpret research findings/data
Mechanics, applied mathematics or theoretical physics
Postdoc position: Accounting for critical plastic fluctuations in FEM codes.
Experiments suggest that plastic flow in low symmetry crystals is scale-free, exhibiting various features of critical behavior. Theoretical modeling of criticality in solids has been mostly focused on prototypical scalar models. These models suggest that a relatively simple threshold nonlinearity at the micro-scale combined with long range interactions and quasi-static driving can generate universal critical behavior at the macro-scale. The objective of this project is to develop comprehensive tensorial models of criticality in crystal plasticity. More specifically, the task is to build a new class of finite element models accounting explicitly for the quantization of plastic slip and operating with 'thick' yield zone implying random thresholds for activation and deactivation of plastic correction. A parallel route is to replace the phenomenological rheological closure relations of continuum models of plasticity by coarse grained stochastic equations accounting for nucleation and immobilization phenomena and represent long range stochastic interactions by a multiplicative mechanical noise. The main challenge is to test and calibrate various stochastic rules of this type by performing a systematic comparison of numerical results with experimentally measured plastic fluctuations in the selected benchmark tests.
1. Salman, U., Truskinovsky L., On the critical nature of plastic flow: One and two dimensional models, International Journal of Engineering Science, 59 , 219–254, 2012
2. Weiss J., Ben Rhouma W., Richeton T., Dechanel S., Louchet F., Truskinovsky L., From mild to wild fluctuations in crystalline plasticity, Phys. Rev. Lett., 114 (10), 105504, 2015
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