月壤钻采取样方式对样品层理的影响

Influence of Coring Methods on Sample Bedding in Lunar Soil Drill-sampling

针对月壤钻采任务,基于离散元月壤模型,分析了硬质管取芯与软袋取芯2种取样方式的层理保持特性,提出了曲面斜率法描述月壤样品的层理信息。该方法能够通过拟合曲面直观反映随钻深分布的各层月壤样品变形情况,并能够定量描述各层样品轻微扰动部分与层理破坏部分的分界范围,以及层理破坏趋势与程度。分析结果表明:取样袋能显著保护样品的层理信息,而硬质管取芯对外侧月壤样品层理破坏严重,且破坏层数较多,但层理破坏较轻微的样品直径范围与有取样袋工况差别不大。此外,2种工况下,表层月壤样品层理信息均破坏严重,说明了表层月壤具有较强的随动性。

Aiming at the lunar soil drill-sampling task,the bedding protection performances of two coring methods,hard tube coring and soft sack coring,are analyzed based on discrete element model. A curved surface slope method is proposed to describe the bedding information of the lunar soil sample. It can directly reflect the deformation of each layer of lunar soil sample distributed with drilling depth by curvefitted surface,and quantitatively illustrate the boundary between the slightly perturbed part and bedding damage part in each layer,and also the trend and degree of the bedding failure. Analysis results show that the soft sack can significantly protect the sample bedding information. The hard tube coring method destroys the bedding of outside sample seriously,and damages more layers,while there is no obvious difference in the scope that is slightly perturbed from the soft sack coring. Additionally,in both work conditions,the bedding information of surface regolith is damaged severely,which indicates that the lunar regolith on the surface has great follow-up property.