An Analysis On Static And Dynamic Mechanical Characteristics Of Pressure-measuring Copper Column

For more than a hundred years, the method of plastic deformation for measuring pressures has been the main mean to test the chamber pressure of conventional weapons because of its advantages that is reliability, convenience and low price. Aimed at a series of theory problem in the static mechanical characteristic and the dynamic mechanical characteristic, a large amount of work has been done in dissertation. The main work consists of the following parts:a) The frictional coefficient between copper cylinder and the interface is one of the most important factor in the copper cylinder upsetting process. According to the diameter height ratio difference, the interface was divided into three parts : sliding area, restraint area, stagnant area. Bases on the difference of the touch,we get the formula between the pressure and distortion. At last, a comparatively satisfactory result based on the performed static formula of mathmatics and physics was obtained, and it is testified by the tests.b) Regarding Rigid-Viscoplastic FEM(the Finite Element Method) as theoretical foundation, an axial symmetry model of ring upsetting was built up through ANSYS software, the copper cylinder upsetting has been simulated by the FEM. Information about the deformed sample, such as mesh distortion, displacement and pressure has been achieved. The deformation patterns were revealed. In order to verify the FEM simulation results, various experiments about copper cylinder pressure measuring were designed and completed. The experiment results indicated that the simulation results are reliable.c) The mathematical model of copper cylinder pressure-measuring system was established according to the pressure-measuring mechanism of copper cylinders and the numerical solution program was made using the Matlab. The simulation of this model has been done and the simulation results comply with the measuring results quite well. According to the simulating calculation, the regularity of copper cylinder deformation under different pressure is obtained.