Experimental and numerical investigation of wrinkling and tube ovality in the rotary draw bending process

The tube wrinkling, ovality, and fracture are the main defects in the rotary draw bending process, which happen by incorrect selection of process parameters. In the present study, the wrinkling, fracture, and ovality of BS 3059 steel tube in the rotary draw bending were investigated using the experimental tests and the finite element method. The numerical results were verified using the experimental tests for tube ovality prediction. The tube fracture was predicted using the Gurson–Tvergaard–Needleman damage model in the rotary draw bending numerical simulations. The design of experiment based on the response surface method and the finite element method was used to investigate the effects of rotary draw bending parameters such as boosting velocity of pressure die, mandrel position, number of balls, and pressure of pressure die on the wrinkling, fracture, and tube ovality. The experimental and numerical results indicated that the mandrel position was one of the main parameters, which influence the tube ovality. The tube ovality and wrinkling increased with the increase in the mandrel position.