De l'impression 3d en céramique
Mesurer la déformation du sel, pour l'aménagement de réservoirs en cavités salines
Electromagnetic forming process for metallic pieces
Amélioration de la performance des éoliennes
Vers un stockage géologique du C02 avec impuretés
Yi ZHANG will defend his thesis called
"Robust modeling and numerical simulation of ductile damage"
on January, 26th, at 10am
at Ecole des mines de Paris, 60 boulevard Saint-Michel, 75006 Paris
in room L109
Abstract : The major goal of this dissertation is to develop a robust model for ductile damage simulation. Because of the softening behavior and the significantly large deformation in ductile damage, two principle difficulties should be dealt with carefully: mesh-dependency and volumetric locking. In this thesis, we adopt a logarithmic finite strain framework in which the Gurson-Tvergaard-Needleman constitutive law is reformulated. Then a non-local formulation with regularization of hardening variable is applied so as to solve mesh dependency and strain localization problem. In addition, the non-local model is combined with mixed “displacement-pressure-volume variation” elements to avoid volumetric locking. Thereby we establish a mesh-independent and locking-free finite strain framework for ductile damage modelling. Attention is paid to mathematical properties and numerical performance of the model. Finally, after an identification work of a nuclear steel, we carry out simulations on normalized specimens (NT, CT, SENT) as well as an industrial tube in order to compare with experimental results.