Stress Path Analysis of Deep-Sea Sediments Under the Compression-Shear Coupling Load of Crawler Collectors

The mechanical properties of deep-sea sediments during the driving process of crawler collectors are essential factors in the design of mining systems.In this study,a crawler load is divided into a normal compression load and a horizontal shear load.Then,the internal stress state of sedimentary soil is examined through a theoretical calculation and finite element numerical simulation.Finally,the driving of crawlers is simulated by changing the relative spatial position between the load and stress unit,obtaining the stress path of the soil unit.Based on the calculation results,the effect of the horizontal shear load on the soil stress response is analyzed at different depths,and the spatial variation law of the soil stress path is examined.The results demonstrate that the horizontal shear load has a significant effect on the rotation of the principal stress,and the reverse rotation of the principal stress axis becomes obvious with the increase in the burial depth.The stress path curve of the soil is different at various depths.The spatial variation rule of the stress path of the shallow soil is complex,whereas the stress path curve of the deep soil tends to shrink as the depth increases.The stress path of the corresponding depth should be selected according to the actual research purpose and applied to the laboratory test.

芝麻联合收获机脱粒装置的设计与试验

当前,我国芝麻收获以人工为主。为了提高我国芝麻收获的机械化水平,促进芝麻产业的良性发展,针对芝麻联合收获中脱粒过程中存在的夹带损失率、含杂率高的问题,基于芝麻蒴果、籽粒的物理特性,对芝麻联合收获机脱粒装置进行设计。选用切流+横轴流的脱粒形式,喂入的芝麻植株先进入切流滚筒,使成熟度较高较易脱粒的芝麻籽粒进行脱粒,未进行脱粒的芝麻进入横轴流滚筒完成脱粒。通过田间试验,对芝麻联合收获机脱粒装置的脱粒效果进行验证,得到夹带损失率为1.93%、破碎率为4.20%。