摘要
ANSYS/LS-DYNA仿真软件,采用SPH/FEM耦合算法模拟旋转刀具切削土壤作业过程。在Solid Works中建立刀具—土壤模型,用ANSYS/LS-DYNA进行前处理,修改K文件建立耦合模型,在LS-PREPOST中查看LS-DYNA9 7 1求解结果 ,对数据进行二次处理,分析作业过程能耗变化及应力分布,为后期优化刀具提供依据。文中土壤本构模型采用MAT_147(MAT_FHWA_SOIL)材料,对材料屈服准则进行详细阐述,相比标准MohrCoulomb屈服准则,修改后的Mohr-Coulomb屈服准则引入了修正系数Ahyp,分析了Ahyp取值对屈服面的影响,得出Ahyp与土壤内聚力和内摩擦角关系;阐述SPH算法和SPH/FEM耦合算法,分别用FEM算法、SPH算法和SPH/FEM耦合算法模拟土壤切削过程。结果表明:在土壤切削前期,网格没有发生畸变时,3种方法模拟结果相近,随着有限元网格发生畸变,FEM算法产生了误差,验证了SPH/FEM耦合算法在土壤切削仿真过程中的可行性与准确性。
Ab stract： In this paper , based on ANSYS/LS-DYNA ,The SPH/FEM coupling algorithm are adopted to simulate the rotary cutter cutting soil process ,tools-soil model is established in the SolidWorks , Before processing in the ANSYS/LS-DYNA and the mod-el is set up by mod-ifeied the K file ,check the LS-DYNA971 results and the datais secondary pro-cessing by th-e LS-PREPOST , analysis of process energy consumption ch-ange and stress distribution , provide the basis for later optimization tool;The soil constitutive model adopts MAT_147 （ MAT_FHWA_SOIL ） materials , the material yieldc-riterion are expounded in details ,co-mpare with the standard mohr-coulomb , Ahyp correction coefficient is intro-duced of The modified mohr-coulomb , analyzed the Ahyp values influence on the yield surface , Ahyp relationship with cohesion and internal friction angle are presented also;Explain SPH algorithm and SPH/FEM coupling algori-thm, using FEM algorithm respectively , SPH algorithm and SPH/FEM coupling algorithm to simulate the soil cutting process ,the re-sults show that in the early stage of the soil cutting , gridwithout distortion occurs , three ways of the simulation results , the finite element mesh distort on caused by FEM algorithm error , thus in SPH/FEM coupling algorithm is verified the feasibility and accuracy in the process of soil cutting simulation .
出处
《农机化研究》
北大核心
2017年第7期21-27,33,共8页
Journal of Agricultural Mechanization Research
基金
国家自然科学基金项目(U1204524)
河南省高等学校骨干教师资助项目(2014GGJS-034)
