In the current work, to predict and improve the formability of deep drawing process for steel plate cold rolled commercial grade （SPCC） sheets, three parameters including the blanking force, the die and punch comer ...In the current work, to predict and improve the formability of deep drawing process for steel plate cold rolled commercial grade （SPCC） sheets, three parameters including the blanking force, the die and punch comer radius were considered. The experimental plan according to Taguchi＇s orthogonal array was coupled with the finite element method （FEM） simulations. Firstly, the data from the test of stress-strain and forming limit curves were used as input into ABAQUS/Explicit finite element code to predict the failure occurrence of deep drawing process. The three parameters were then validated to establish their effects on the press formability. The optimum case found via simulation was finally confirmed through an experiment. In order to obtain the complex curve profile of cup shape after deep drawing, the anisotropic behavior of earring phenomenon was modeled and implemented into FEM. After such phenomenon was correctly predicted, an error metric compared with design curve was then measured.展开更多
An antifogging function surface with simple structure and suitable for large-area production was found inspired by Ephemera pictiventris McLachlan compound eyes.The compound eyes structure,antifogging properties and m...An antifogging function surface with simple structure and suitable for large-area production was found inspired by Ephemera pictiventris McLachlan compound eyes.The compound eyes structure,antifogging properties and mechanism were studied by anti-fog test,dyeing test and scanning electron microscopy,and so forth.Then,3D model of the sample was established,and the antifogging mechanism was explained by the Cassie model.Results showed that the compound eyes are composed of hundreds of micron size ommatidia arranged in curved array form,and this structure shows excellent antifogging function.This research may provide new ideas for design of simple structure and micron size antifogging function surface.This work is also expected to be applied to antifogging function surface of astronaut helmets and medical endoscopes,and so forth.展开更多
A boundary element method for three-dimensional steady ship wave-making potential problems is established with the Rankine source function as its fundamental solution. In the treatment of the linearized free surface c...A boundary element method for three-dimensional steady ship wave-making potential problems is established with the Rankine source function as its fundamental solution. In the treatment of the linearized free surface condition, one-sided, upstream finite difference operator (FDO) is used to suppress the upstream waves, and the equation of the disturbance velocity is established so that the first order FDO can be used in place of the second order FDO. Compared with the method with the second order FDO, the current method gives better precision and stability. Numerical examples are presented for verification.展开更多
基金Project(107.02-2013.01)supported by the Vietnam’s National Foundation for Science and Technology Development
文摘In the current work, to predict and improve the formability of deep drawing process for steel plate cold rolled commercial grade （SPCC） sheets, three parameters including the blanking force, the die and punch comer radius were considered. The experimental plan according to Taguchi＇s orthogonal array was coupled with the finite element method （FEM） simulations. Firstly, the data from the test of stress-strain and forming limit curves were used as input into ABAQUS/Explicit finite element code to predict the failure occurrence of deep drawing process. The three parameters were then validated to establish their effects on the press formability. The optimum case found via simulation was finally confirmed through an experiment. In order to obtain the complex curve profile of cup shape after deep drawing, the anisotropic behavior of earring phenomenon was modeled and implemented into FEM. After such phenomenon was correctly predicted, an error metric compared with design curve was then measured.
基金supported by the National Natural Science Foundation of China (51175220,51290292,51325501)Jilin Science and Technology Development Project (20111808)
文摘An antifogging function surface with simple structure and suitable for large-area production was found inspired by Ephemera pictiventris McLachlan compound eyes.The compound eyes structure,antifogging properties and mechanism were studied by anti-fog test,dyeing test and scanning electron microscopy,and so forth.Then,3D model of the sample was established,and the antifogging mechanism was explained by the Cassie model.Results showed that the compound eyes are composed of hundreds of micron size ommatidia arranged in curved array form,and this structure shows excellent antifogging function.This research may provide new ideas for design of simple structure and micron size antifogging function surface.This work is also expected to be applied to antifogging function surface of astronaut helmets and medical endoscopes,and so forth.
文摘A boundary element method for three-dimensional steady ship wave-making potential problems is established with the Rankine source function as its fundamental solution. In the treatment of the linearized free surface condition, one-sided, upstream finite difference operator (FDO) is used to suppress the upstream waves, and the equation of the disturbance velocity is established so that the first order FDO can be used in place of the second order FDO. Compared with the method with the second order FDO, the current method gives better precision and stability. Numerical examples are presented for verification.
