Temperature influences of the recoil characteristics for aluminum honeycomb buffer in the tether-net launcher

Fluctuations in outer space's temperature would affect the spacecraft's regular operation.This paper aims to study the temperature influences of the aluminum honeycomb buffer in the tether-net launcher.Firstly,a buffer structure was designed to attenuate the pyroshock generated by the pyrotechnic device.Secondly,the mechanical properties of aluminum honeycomb at different temperatures were obtained through quasi-static compression experiments.Then,the internal ballistic responses of the launcher were gained by the closed bomb tests and the equivalent classical interior ballistic model.Finally,the recoil performance of the launcher with aluminum honeycomb buffer at different temperatures was studied.It is revealed that the aluminum honeycomb crushing force gradually decreases with the temperature increases.The peak pressure,burning rate coefficient and velocity increase while the peak time decreases with the temperature increase for the interior ballistics.For the launcher recoil responses,the average launch recoil decreases if the aluminum honeycomb doesn't enter the dense stage.The impact acceleration,projectile velocity and displacement increase as the temperature increase.The paper spotlights the temperature's influence on the recoil characteristics of the aluminum honeycomb buffer,which provides a new idea for buffering technology of pyrotechnic devices in a complex space environment.

A Study on Criteria for Barrel Lifetime

Several criteria for barrel lifetime were summarized and discussed. Based on large amount of test data,the advantages and disadvantages of the criteria were analyzed and the requirements for the easy and practical criterion were put forward. Then,a new criterion based on the radical wear at the start points of the barrel lands was proposed. The close interrelationship between the radical wear and interior ballistic characteristics was illuminated theoretically and experimentally. The research results show the great value of this criterion to solve the problem of barrel lifetime.

Numerical simulation of the coupled dynamics model of the projectile engraving process

The projectile engraving process directly influences the projectile motion in-bore and impacts the firing accuracy,firing safety,and barrel life of the gun.For this reason,attention has been focused on this research topic.To address the limitations of the“instantaneous engraving”hypothesis adopted in the classical interior ballistic theory,the VUAMP user subroutine,one of ABAQUS's secondary development interfaces,is utilized in this paper to realize the modeling and numerical simulation of a coupled dynamics model of the projectile engraving process.In addition to facilitating engineering applications,a polynomial fitting formula of the engraving resistance obtained by simulation is proposed and then used as a supplement to establish a closed and solvable interior ballistic model considering the projectile engraving process.By comparing with test data,the simulation accuracy of the coupled dynamics model is verified.Simulation results reveal that the engraving process takes 3.8 ms,accounting for 26%of the whole launch process,which takes 14.6 ms,demonstrating that the process is not instantaneous.The results of this paper can serve as a reference for future studies on the coupled solution of the projectile engraving process and interior ballistics of guns or gun-like equipment.