Numerical Thermal Load Analysis Of Typical Rigid Lunar Base Structure

Exploring the vast universe,developing the space industry,and building a strong space nation are the space dreams we relentlessly pursue.Since the moon is the nearest celestial body to the earth,the construction of a lunar base is of strategic significance for further deep space exploration and resource exploitation.The alien bases are faced with severe service environment,where the extreme thermal loads have great potential threat to the safety of the base structure.Therefore,this thesis aims at a typical rigid lunar base,using the finite element simulation software ANSYS,to carry out a numerical simulation study of structural thermal coupling.Firstly,the numerical calculation method of the rigid lunar base structure thermal load is established.Based on the lunar thermal radiation environment,the energy balance relationship of the lunar base is established.Under the action of multiple energy sources,the lunar base temperature field control equation and boundary equation are established to form a lunar base temperature field and thermal stress calculation and analysis method.In this method,the numerical simulation of the temperature field of a typical rigid lunar base structure is carried out under the simulation results.The simulation results show that the temperature fluctuation of the lunar base during the entire period is huge,the maximum temperature can reach more than 400 K,the temperature of the structure's sunny side is high,and the temperature of the back side is low;on this basis,assuming that there is convection on the moon,the simulation results show that the presence of atmospheric convection has a significant effect on slowing temperature fluctuations,and the maximum temperature is only 359.3 K;in addition,the analysis of the interaction between the lunar base and the lunar surface shows that the radiation effect between the two causes the temperature of both to rise,which is even more detrimental to the structure.Secondly,the numerical calculation method of the thermodynamic coupling of the rigid lunar base structure is used.The result of the temperature field is used as the load of the static analysis to realize the thermal-mechanical coupling.The changes of the maximum stress and deformation of the structure during the day and night are analyzed.The analysis results show that the thermal stress at the base connection is the largest.When it is assumed that the connection is fixed-end constraint,the maximum can reach 854 MPa,and the change trend of the maximum thermal stress is the same as the temperature;in addition,the reference temperature is explored by setting five sets of reference temperatures of 120 K,180 K,240 K,300 K,and 360 K.The results show that the reference temperature of 300 K is the best among the five groups to reduce the thermal stress effect.For components with large temperature fluctuations,it is best to reduce the thermal stress effect by setting the installation temperature of the component in the middle of the temperature fluctuations when constructing the base.Finally,ways to reduce the thermal loading effect of the rigid lunar base are proposed.The way of reducing the thermal load is analyzed,and the simulation is explored through different connection methods,different materials,and different construction directions.The simulation results show that the constraint has a great influence on the generation of thermal stress.Considering the required stability of the lunar base structure,the sliding support is the most suitable choice;among the four materials Ti,Mg,Fe,and Al,the resistance to thermal load Ti is the strongest,Mg and A1 are second,and Fe is the worst;the maximum temperature of the lunar base structure constructed in the east-west direction is 378.8 K during the lunar day and night,which is 23 K less than the maximum temperature in the north-south direction,and the time for the high temperature to stay at the base becomes shorter which has obvious effect on reducing thermal load.