The new flexible forming technique of sheet metal laser bending process is numerically simulated by using finite element method of large elastic plastic deformation. The temperature fields and stress strain distrib...The new flexible forming technique of sheet metal laser bending process is numerically simulated by using finite element method of large elastic plastic deformation. The temperature fields and stress strain distribution in deformation area are calculated, forming process is described and relationship between bend angle and width of sheet is discussed. It is shown that the calculated values are in good accordance with the experiments.展开更多
Stresses and deformation states of pipe bending are investigated under loading or unloading with various pipe materials, size, bending radius and deformation temperature. A theorem of springback of large diameter pipe...Stresses and deformation states of pipe bending are investigated under loading or unloading with various pipe materials, size, bending radius and deformation temperature. A theorem of springback of large diameter pipe bending is presented. The experiments are carried out with pipe materials of 20, 10CrMo910 and 12Cr1MoV steel. Results of computations are in good agreement with experiments.展开更多
Because of the light weight,high stiffness and high structural efficiency,aluminium alloy integral panels are widely used on modern aircrafts.Press bend forming has many advantages,and it becomes a significant techniq...Because of the light weight,high stiffness and high structural efficiency,aluminium alloy integral panels are widely used on modern aircrafts.Press bend forming has many advantages,and it becomes a significant technique in aircraft manufacturing field.In order to design the press bend forming path for aircraft integral panels,we propose a novel optimization method which integrates the finite element method(FEM) equivalent model based on our previous study,the artificial neural network response surface,and the genetic algorithm. First,a multi-step press bend forming FEM equivalent model is established,with which the FEM experiments designed with Taguchi method are performed.Then,the backpropagation(BP) neural network response surface is developed with the sample data from the FEM experiments.Further more,genetic algorithm(GA) is applied with the neural network response surface as the objective function.Finally,experimental and simulation verifications are carried out on a single stiffener specimen.The forming error of the panel formed with the optimal path is only 5.37%and the calculating efficiency has been improved by 90.64%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.展开更多
文摘The new flexible forming technique of sheet metal laser bending process is numerically simulated by using finite element method of large elastic plastic deformation. The temperature fields and stress strain distribution in deformation area are calculated, forming process is described and relationship between bend angle and width of sheet is discussed. It is shown that the calculated values are in good accordance with the experiments.
文摘Stresses and deformation states of pipe bending are investigated under loading or unloading with various pipe materials, size, bending radius and deformation temperature. A theorem of springback of large diameter pipe bending is presented. The experiments are carried out with pipe materials of 20, 10CrMo910 and 12Cr1MoV steel. Results of computations are in good agreement with experiments.
基金the National Natural Science Foundation of China(Nos.51205004 and 51005010)
文摘Because of the light weight,high stiffness and high structural efficiency,aluminium alloy integral panels are widely used on modern aircrafts.Press bend forming has many advantages,and it becomes a significant technique in aircraft manufacturing field.In order to design the press bend forming path for aircraft integral panels,we propose a novel optimization method which integrates the finite element method(FEM) equivalent model based on our previous study,the artificial neural network response surface,and the genetic algorithm. First,a multi-step press bend forming FEM equivalent model is established,with which the FEM experiments designed with Taguchi method are performed.Then,the backpropagation(BP) neural network response surface is developed with the sample data from the FEM experiments.Further more,genetic algorithm(GA) is applied with the neural network response surface as the objective function.Finally,experimental and simulation verifications are carried out on a single stiffener specimen.The forming error of the panel formed with the optimal path is only 5.37%and the calculating efficiency has been improved by 90.64%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.
