Effects of Load Type on the Mechanical Properties of the JLU Series Lunar Soil Simulant

The pressure-sinkage characteristics and the shear-strength characteristics of lunar regolith are the important influence factors to the trafficability of lunar rover. The performance curves and parameters of JLU luanr soil simulant were obtained by pressure-sinkage tests and shear-strength tests in the ground gravity-environmental load (1g) and the lunar gravity-environmental load (1/6g). The results show that, for the pressure-sinkage characteristics, the compression-strength of the JLU-1 is strongest, followed by the JLU-3, and the JLU-2 is the weakest. In different load levels, the deformability index n increases as the bulk density increases. The kc increase as the state becoming more and more compact,The k of JLU-1 is the largest of all, followed by JLU-3 next, JLU-2 has the smallest.The load levels have no significant effect to the tendency of n, kc and k. For the shear-strength characteristics, the shear resistance of JLU-2 is the weakest. JLU-1 has the greatest cohesion c of the three lunar soil simulant, followed by JLU-3, the c of JLU-2 is the smallest.The c of the same lunar soil simulant in natural state is greater than it in soft state. Compared with JLU-1 and JLU-3, JLU-2 has the smallest internal friction angle .The influence of the load levels to the the cohesion c internal friction angel is not obvious. The  mesured in the lunar load is wider than it in the ground load. This study will supply fundamental reference and foundation on the research and optimization of the lunar rover traveling mechanism in the authentic lunar environment.