A numerical method for coupled deformation between sheet metal and flexible-die was proposed. Based on the updated Lagrangian （UL） formulation, the elastoplastic deformation of sheet metal was analyzed with finite e...A numerical method for coupled deformation between sheet metal and flexible-die was proposed. Based on the updated Lagrangian （UL） formulation, the elastoplastic deformation of sheet metal was analyzed with finite element method （FEM） and the bulk deformation of flexible-die was analyzed with element-free Galerkin method （EFGM）. The frictional contact between sheet metal and flexible-die was treated by the penalty function method. The sheet elastic flexible-die bulging process was analyzed with the FEM-EFGM program for coupled deformation between sheet metal and bulk flexible-die, called CDSB-FEM-EFGM for short. Compared with finite element code DEFORM-2D and experiment results, the CDSB-FEM-EFGM program is feasible. This method provides a suitable numerical method to analyze sheet flexible-die forming.展开更多
A commercial AA7108 aluminium alloy subjected to different quenching procedures from the solid solution temperature of 480 ℃ was considered. Both continuously cooling and quenching to intermediate temperatures （400,...A commercial AA7108 aluminium alloy subjected to different quenching procedures from the solid solution temperature of 480 ℃ was considered. Both continuously cooling and quenching to intermediate temperatures （400, 300 and 200 ℃） followed by different holding times were applied. All the materials were subsequently subjected to the same industrial two-step artificial ageing procedure to obtain a maximum strength （T6）. Tensile testing of the different quenched materials in the T6 temper reveals a large deviation in strength dependent on the cooling/holding time, compared with the reference sample. A collection of the different quenched materials was chosen for further investigation of the precipitate structure by transmission electron microscopy （TEM） to explain the differences in mechanical properties.展开更多
基金Project(51275130)supported by the National Natural Science Foundation of China
文摘A numerical method for coupled deformation between sheet metal and flexible-die was proposed. Based on the updated Lagrangian （UL） formulation, the elastoplastic deformation of sheet metal was analyzed with finite element method （FEM） and the bulk deformation of flexible-die was analyzed with element-free Galerkin method （EFGM）. The frictional contact between sheet metal and flexible-die was treated by the penalty function method. The sheet elastic flexible-die bulging process was analyzed with the FEM-EFGM program for coupled deformation between sheet metal and bulk flexible-die, called CDSB-FEM-EFGM for short. Compared with finite element code DEFORM-2D and experiment results, the CDSB-FEM-EFGM program is feasible. This method provides a suitable numerical method to analyze sheet flexible-die forming.
文摘A commercial AA7108 aluminium alloy subjected to different quenching procedures from the solid solution temperature of 480 ℃ was considered. Both continuously cooling and quenching to intermediate temperatures （400, 300 and 200 ℃） followed by different holding times were applied. All the materials were subsequently subjected to the same industrial two-step artificial ageing procedure to obtain a maximum strength （T6）. Tensile testing of the different quenched materials in the T6 temper reveals a large deviation in strength dependent on the cooling/holding time, compared with the reference sample. A collection of the different quenched materials was chosen for further investigation of the precipitate structure by transmission electron microscopy （TEM） to explain the differences in mechanical properties.
