Fracture Prediction Of Intellient Deep Drawing For Rectangular Box

The intellectualization of sheet metal forming is the process in which, through an organic combination of sheet metal forming theory with control theory and computer science, and based on the characteristics of the workpiece to be worked, the material properties are identified and the optimum technique parameters are predicted on-line by means of easily-monitored physical quantities and the forming is automated to those parameters thus determined. Intelligent deep drawing for rectangular box is a important field intelligent deep drawing of plates. According to mechanics characteristic of sheet metal forming, this paper emphatically considers the influence of equivalent plastic strain on void-damage on the basis of continuous damage mechanics theory. Furthermore, with talking Lemaitre damage equivalent stress as plastic potential, a criterion for ductile fracture is first derived. The fracture prediction of deep drawing for rectangular box is based on the continuous damage mechanics theory. Using finite element method (FEM) simulation, the blank holder force(BHF) for fracture is gained on the base of analysis of facture in different BHF and drawing depth. Real-time monitoring and control depend on the development of data acquisition (DAQ) technology. Based on the portable DAQ system of LabVIEW, the signal acquisition and sensor calibration both get the satisfied speed and precision of signals. The merits such as the high speed of dater acquisition, the strong anti-interference ability of signal and high precision for this new DAQ system can cover the shortage of former DAQ system based on control software Genie. On the base of the criterion for the facture and FEM simulation under the real condition, the experiment research for facture of rectangular box deep drawing is carried and the results which provides the data indicates the theory analysis is reliable and effective are gained. The experiment research proves the theory analysis for the fracture in deep drawing can also be used to design the tooling, process parameters and the basis of intellectual control in sheet metal forming.