Experimental Research And Numerical Simulation On Explosive Forming Of Elliptical Head

Metal head piece, which is often made by drawing technology, is an important and indispensable part of the pressure vessal equipment in variable fields from petrochemical processing, atomic energy to pharmacy. For its application environment, the features of high pressure resistance, strong corrosion resistance and long service life are required. So the materials that are used to made the head usually have large hardness and high strength. Especially for some workpieces with a small-amount, large size and complicated shapes, the use of conventional forming means need to be equipped with large stamping devices, time-consuming and costly, and it is still difficult to complete. However, explosive forming technology will be a good choice, it has some features with high dimensional accuracy, surface finish, high efficiency and energy-saving, which make up for the deficiencies of conventional forming approachs. In this paper, the theoretical analysis, experimental study and numerical simulation will be used to research on explosive forming process of elliptical head.Firstly, according to the summary of the theoretical analysis and engineering experiences, some reasonable conditions of explosive forming process can be provided.Secondly, To solve the best parameters in the explosive forming process of elliptical head, a set of experimental device is designed. With TNT as a source of energy, sand and water as the energy transferred medium, thin1060H24aluminum sheet plates and thin Q235B steel sheet plates as blanks, the processes of explosive forming were conducted. Adopting different energy transferred medium in the forming results in different forming quality. The specific bursting height(h/m1/3) relates to the center deflection of the head which provides a way to acquire the most appropriate process parameters. The results indicated that the efficiency of water is much better than sand. Whether the value of h/1/3is too high or low, it will all affect the explosiive forming quality of head. The best value of h/m1/3in the given condition is about0.26. The formed heads have smooth surface without obvious defects.Thirdly, explosive forming process was numerically simulated using finite software ANSYS/LS-DYNA. The velocity, displacement, pressure distribution, effective plastic strain of the forming plate element were obtained during the explosive forming process. Compared with theoretical calculation and test results, there is a certain gap between the simulation results and the obove. Taking into account the conditions are not completely consistent, the error is acceptable. The results showed that the mathematical model, simulate method can be used to correctly simulate the process of explosive forming. Through numerical simulate method, it is very convenient to descripe explosive forming process and easy to predict explosive forming technology parameters. In the end, it will provide a very good reference for the selections of optimal explosive forming parameters in practical engineering application.