Research on damage evolution and fracture prediction in hydraulic continuous rotary bending low-stress cropping

Abstract

Due to the complexity of the near-net shape forming mechanism in the low-stress cropping(LSC) process, it is a challenge to accurately predict the process of fracture separation. A shear modified GTN model is proposed to study the fracture mechanism of hydraulic continuous rotary bending low-stress cropping(HCRB-LSC), and is applied to simulate the material damage evolution and predict the fracture behaviour of HCRB-LSC. Moreover, the rationality and validity of simulation results are verified by precision cropping experiments. Combined with the proposed evaluation method and evaluation index of the cross-section, the quality of cross-section obtained by cropping is quantitatively evaluated. It is found that this cropping method could increase the accuracy of the cross-section and the efficiency of cropping, and could efficiently achieve reasonable sectional accuracy and flatness at 8mm loading position. Precise prediction of near-net-shape forming damage evolution and fracture in HCRB-LSC provides an important basis for subsequent optimization of the precision cropping process.