Peridynamics(PD)is a non-localmechanics theory that overcomes the limitations of classical continuummechanics(CCM)in predicting the initiation and propagation of cracks.However,the calculation efficiency of PDmodels i...Peridynamics(PD)is a non-localmechanics theory that overcomes the limitations of classical continuummechanics(CCM)in predicting the initiation and propagation of cracks.However,the calculation efficiency of PDmodels is generally lower than that of the traditional finite elementmethod(FEM).Structural idealization can greatly improve the calculation efficiency of PD models for complex structures.This study presents a PD shell model based on the micro-beam bond via the homogenization assumption.First,the deformations of each endpoint of themicro-beam bond are calculated through the interpolation method.Second,the micro-potential energy of the axial,torsional,and bending deformations of the bond can be established from the deformations of endpoints.Finally,the micro moduli of the shellmodel can be obtained via the equivalence principle of strain energy density(SED).In addition,a new fracture criterion based on the SED of the micro-beam bond is adopted for crack simulation.Numerical examples of crack propagation are provided,and the results demonstrate the effectiveness of the proposed PD shell model.展开更多
The double-hat-shaped magnesium tube was difficult to use in actual applications due to its frangible material property.Magnesium alloy and traditional steel were integrated into a new hybrid thin-walled double-hat-sh...The double-hat-shaped magnesium tube was difficult to use in actual applications due to its frangible material property.Magnesium alloy and traditional steel were integrated into a new hybrid thin-walled double-hat-shaped tube to improve vehicle crashworthiness.Two classes of hybrid tubes were examined,namely Hybrid-I(steel top hat and magnesium alloy bottom hat)and Hybrid-II(magnesium alloy top hat and steel bottom hat).The energy absorption characteristics and crashworthiness optimization of the thin-walled hybrid structures were investigated under three-point bending conditions through experiments and simulations.Multi-objective optimization design for the two hybrid tubes was implemented to elucidate their lightweight properties.Results showed that the specific energy absorption of Hybrid-I tube and Hybrid-II tube was approximately 44.7%and 12.7%higher than that of the double-hat-shaped DC04 tube,respectively.The Hybrid-I tube had better crashworthiness and lightweight properties compared with Hybrid-II tube.Hybrid-I tube also had better lightweight properties than single-material steel tube and reduced wall thickness compared with magnesium alloy tube.展开更多
基金funded by Project of the National Natural Science Foundation of China(Grant No.11872017).
文摘Peridynamics(PD)is a non-localmechanics theory that overcomes the limitations of classical continuummechanics(CCM)in predicting the initiation and propagation of cracks.However,the calculation efficiency of PDmodels is generally lower than that of the traditional finite elementmethod(FEM).Structural idealization can greatly improve the calculation efficiency of PD models for complex structures.This study presents a PD shell model based on the micro-beam bond via the homogenization assumption.First,the deformations of each endpoint of themicro-beam bond are calculated through the interpolation method.Second,the micro-potential energy of the axial,torsional,and bending deformations of the bond can be established from the deformations of endpoints.Finally,the micro moduli of the shellmodel can be obtained via the equivalence principle of strain energy density(SED).In addition,a new fracture criterion based on the SED of the micro-beam bond is adopted for crack simulation.Numerical examples of crack propagation are provided,and the results demonstrate the effectiveness of the proposed PD shell model.
基金the National Natural Science Foundation of China(51405060).
文摘The double-hat-shaped magnesium tube was difficult to use in actual applications due to its frangible material property.Magnesium alloy and traditional steel were integrated into a new hybrid thin-walled double-hat-shaped tube to improve vehicle crashworthiness.Two classes of hybrid tubes were examined,namely Hybrid-I(steel top hat and magnesium alloy bottom hat)and Hybrid-II(magnesium alloy top hat and steel bottom hat).The energy absorption characteristics and crashworthiness optimization of the thin-walled hybrid structures were investigated under three-point bending conditions through experiments and simulations.Multi-objective optimization design for the two hybrid tubes was implemented to elucidate their lightweight properties.Results showed that the specific energy absorption of Hybrid-I tube and Hybrid-II tube was approximately 44.7%and 12.7%higher than that of the double-hat-shaped DC04 tube,respectively.The Hybrid-I tube had better crashworthiness and lightweight properties compared with Hybrid-II tube.Hybrid-I tube also had better lightweight properties than single-material steel tube and reduced wall thickness compared with magnesium alloy tube.
