Application of Distinct Element Method to analyze machine-soil interaction

应用离散单元法，对机械与土壤的相互作用进行了模拟实验，该方法是分析颗粒材料组合行为的有效方法之一。结果表明，只要找到合适的参数，就可以利用DEM进行机械零件的合理设计。它们的相互作用是：1.三轴压缩；2.履带与土壤；3.轮胎耳片与土壤；4.旋翼与土壤；5.深松与土壤。在此基础上，根据真实世界的维度构建了三维DEM程序。最后的报告是英文的，内容如下：第一章绪论第二章离散单元法概述第三章离散元模拟土体侵彻时的变形和抗力第四章DEM模拟三轴压缩时土体的变形和应力变化第五章DEM模拟履带与土壤的相互作用第六章DEM在模拟土壤与轮胎耳片相互作用中的应用第七章DEM在模拟土壤与旋转叶片相互作用中的应用第八章，DEM在土壤与深松小腿相互作用模拟中的应用，第九章。三维DEM，模拟土壤与轮胎耳片之间的相互作用，第十章。结论。

Applying the Distinct Element Method, which is one of promising methods to analyze behaviors of granular material assembly, the following trials were done to simulate the interactions between machine and soil. It was shown that the rational design of machine part would be realyzed using the DEM, if the adequate parameters were found. The interactions were : 1. tri-axial compression, 2. track shoe and soil, 3. tire lug and soil, 4. rotary blade and soil, 5. subsoiler and soil. Furthermore, three-dimensional DEM program was constructed according to the real world dimension. The problem that the computation time increases very much in the case of three-dimensional DEM should be solved hereafter.The final report was written in English with the following contents :Chapter 1. Introduction, Chapter 2. Outline of Distinct Element Method, Chapter 3. Simulation of soil deformation and resistance at bar penetration by DEM, Chapter 4. Simulation of soil deformation and stress variation at 3-axial compression by DEM, Chapter 5. Simulation of track shoe-soil interaction by DEM, Chapter 6. Application of DEM to simulate interaction between soil and tire lug, Chapter 7. Application of DEM to simulate interaction between soil and rotary blade, Chapter 8. Application of DEM to simulate interaction between soil and subsoiler shank, Chapter 9. 3-dimensional DEM for simulation of interaction between soil and tire lug, Chapter 10. Conclusion.