A modified Gurson-Tvergaard-Needleman （GTN） model that accounts for the mixed （isotropic and kinematic） hardening of cast steel GS-20Mn5V was developed and implemented in the finite dement program ABAQUS/Standard ...A modified Gurson-Tvergaard-Needleman （GTN） model that accounts for the mixed （isotropic and kinematic） hardening of cast steel GS-20Mn5V was developed and implemented in the finite dement program ABAQUS/Standard via a user-defined material subroutine UMAT. This model couples the stress state and damage evolution （pore volume fraction increase） by a classic method that assumes that the total void volume fraction is divided into a nucleation and a growth part. A parametric study was conducted to assess the effect of modified GTN model parameters on mechanical properties such as the nucleation, growth and coalescence of voids and to obtain the optimal parameter combination by the orthogonal test method. The predicted load-displacement curves of notched specimens with the optimal parameters are favorably compared to the experimental curves. Therefore, the modified GTN model can be used to predict the damage evaluation and fracture behavior of GS-20Mn5V.展开更多
We study the direct product decomposition of quantum many-valued algebras (QMV algebras) which generalizes the decomposition theorem of ortholattices (orthomodular lattices).In detail,for an idempo- tent element of a ...We study the direct product decomposition of quantum many-valued algebras (QMV algebras) which generalizes the decomposition theorem of ortholattices (orthomodular lattices).In detail,for an idempo- tent element of a given QMV algebra,if it commutes with every element of the QMV algebra,it can induce a direct product decomposition of the QMV algebra.At the same time,we introduce the commutant C(S) of a set S in a QMV algebra,and prove that when S consists of idempotent elements,C(S) is a subalgebra of the QMV algebra.This also generalizes the cases of orthomodular lattices.展开更多
基金The National Key Research and Development Program of China(No.2017YFC0805103)the National Natural Science Foundation of China(No.51578137,51438002,51108075)the Open Research Fund Program of Jiangsu Key Laboratory of Engineering Mechanics
文摘A modified Gurson-Tvergaard-Needleman （GTN） model that accounts for the mixed （isotropic and kinematic） hardening of cast steel GS-20Mn5V was developed and implemented in the finite dement program ABAQUS/Standard via a user-defined material subroutine UMAT. This model couples the stress state and damage evolution （pore volume fraction increase） by a classic method that assumes that the total void volume fraction is divided into a nucleation and a growth part. A parametric study was conducted to assess the effect of modified GTN model parameters on mechanical properties such as the nucleation, growth and coalescence of voids and to obtain the optimal parameter combination by the orthogonal test method. The predicted load-displacement curves of notched specimens with the optimal parameters are favorably compared to the experimental curves. Therefore, the modified GTN model can be used to predict the damage evaluation and fracture behavior of GS-20Mn5V.
基金supported by National Natural Science Foundation of China (Grant Nos. 60736011, 61073023 and 60603002)the National Basic Research Program of China (973 Program) (Grant No. 2009CB320701)
文摘We study the direct product decomposition of quantum many-valued algebras (QMV algebras) which generalizes the decomposition theorem of ortholattices (orthomodular lattices).In detail,for an idempo- tent element of a given QMV algebra,if it commutes with every element of the QMV algebra,it can induce a direct product decomposition of the QMV algebra.At the same time,we introduce the commutant C(S) of a set S in a QMV algebra,and prove that when S consists of idempotent elements,C(S) is a subalgebra of the QMV algebra.This also generalizes the cases of orthomodular lattices.
