Analysis Of Cold Drawing Tubes And Welded Tubes Process By Non-linear Finite Element Method

The non-linear finite element method that include large deformation elastic plastic and nonlinear contact and multi-physics FEA software—ANSYS were used to understand the stress and strain distributing rules and the influences on forming precision of the forming process of cold drawing tube under different material models and hardening rules, to understand the stress and strain distributing rules of the first stand forming process of single-radius and double-radius welded tube. In the process of the simulation, the deformation of the dies was considered. The results are as follows:(1) The forming process of the non-mandrel tube drawing in both arc die and cone die was simulated. The numerical simulation results show that the diameter of the tube is closer to the designing value when arc die was used, and the wall thickness is closer to the designing value When cone die was used.(2) The influences of both the material models and the hardening rules on the drawing forces and precision of the forming were studied. The results show that the simulation results are more useful under real material model when kinematics hardening rule is used.(3) The forming process of the plug tube drawing in both arc die and cone die was simulated. The numerical simulation results show that the drawing force and pulling force are lager when arc die was used, meanwhile the diameter and wall thickness are closer to the designing value when cone die was used.(4) A hybrid experiment method combined numerical modeling and experiment has been developed, the second residual stresses in the inside of the tube have been measured. The rules between the residual stress and the bearing capacity of the hydraulic cylinder are obtained.(5) The first stand forming process of single-radius and double-radius welded tube was simulated. The numerical simulation results show that the distribution of the stress and strain is not well-proportioned, so the multi-radius forming method should be considered in the future. At last, the future study direction on the forming process of welded tube under the multi-roller is put forward.