侵彻过程中弹引螺纹连接结构振动特性研究

In view of the projectile fuze system in the process of penetration, the vibration characteristics of the threaded connection between a projectile and a fuze were studied. An elastic model for the missile fuze threaded connection between projectile and fuze was established. This model took the uneven distribution characteristics of the thread load into consideration. Not only the distribution law of the thread load was given, but also the equivalent stiffness and vibration frequency of the threaded connection structure were given. At the same time, in order to verify the correctness of the model, the finite element simulation and the static tensile and impact tests of the spring thread connection structure were carried out. The frequency characteristics of the system were obtained by calculating the vibration characteristics of each structure and analyzing the measured overload signals. Finally, the vibration frequency of the projectile-fuze system was compared with the time-frequency analysis results of the measured overload signal. For impact load and static load, the results of calculation and test show that the load on the first thread close to the force action point is the largest, and the load on the threads far away from the action point decreases gradually. Compared with the static load, the first thread supports more load under the impact load. The stiffness of the screw connection structure is obviously lower than that of the fixed connection structure. By increasing the stiffness of the thread material, increasing the screw length and reducing the pitch, the natural frequency of the threaded connection structure can be effectively increased. Based on the time-frequency analysis of the penetration overload test signals, it is found that there is a signal having the same vibration frequency with that of the threaded connection structure. Moreover, the amplitude of this signal is very high and it has a great impact on the overload signal.