Friction Temperature Of Warhead During Penetrating Lunar Soil Of Permanent Shadow Area

The development and utilization of volatile components such as lunar soil,water and ice in the permanent shadow area is of great significance to promote the implementation of the "Chang’e 7" lunar exploration project.The detection of the attached state of lunar soil subsurface water needs the help of thermal induction of penetrator.Aiming at the problem of heat source,this paper studies from the following aspects:1)According to the previous conclusion that frozen soil is used to simulate the sub surface lunar soil in the permanent shadow area of water ice,the parameters and mechanical properties of frozen soil under-145～-240℃ ambient temperature and different moisture content in the permanent shadow area are studied from the perspective of penetration.It is found that its properties are similar to those of concrete with low compressive strength.2)Aiming at the penetration of projectile into low strength concrete target,a calculation method of friction temperature rise of projectile head based on micro element method is proposed.Based on Forrestal penetration resistance method and friction thermo DYNAmics theory,combined with micro element method,the functional relationship between axial force,friction,friction heat and temperature of penetrator is established.3)The finite element model of projectile target considering only friction heating effect is established by using ANSYS/LS-DYNA software,and the thermal solid coupling analysis is carried out,and the friction heating characteristic curve of the penetrator head is obtained;4)The penetration friction temperature measurement system is designed,and the temperature curve is obtained.The curve data is complete and can better reflect the friction heating characteristics at the warhead in the process of penetration.The results of theory,simulation and experiment are in good agreement,which shows the correctness of micro element friction heating method,the rationality of simulation model and the reliability of temperature measurement system,which lays a solid foundation for the next research on friction heating of lunar soil penetration.