仿生镇压辊减粘降阻的有限元分析与试验验证

Finite Element Analysis and Experimental Verification of Bionic Press Roller in Reducing Adhesion and Resistance

利用ABAQUS软件建立了传统镇压辊和仿生镇压辊与土壤相互作用的三维有限元模型。模拟结果中伪应变能约占内能的0.1%,传统镇压辊和仿生镇压辊的牵引阻力的模拟值和试验值相对误差分别为11.47%和2.38%,模拟值和试验值吻合较好,验证了模型的可靠性。从Mises应力云图、镇压辊与土壤接触面积和位移云图3方面对2种镇压辊的模拟结果进行了对比。结果表明:仿生镇压辊与土壤的接触应力显著大于传统镇压辊,更利于将土壤表层的土块压碎;仿生镇压辊与土壤的接触面积比传统镇压辊降低了79.05%,有利于降低土壤与仿生镇压辊表面的粘附力,且土槽试验结果得到仿生镇压辊的粘附土壤量比传统镇压辊降低52.78%;仿生镇压辊表面的肋条结构能在一定程度上约束土壤流动,避免了壅土现象的产生;2种镇压辊的下陷量相差很小,压实阻力基本相同,但仿生镇压辊更利于压实表层土壤;传统镇压辊造成土壤沿镇压辊宽度方向的位移扰动量大于仿生镇压辊,需要消耗更多的功。土槽试验结果表明:与传统镇压辊相比,仿生镇压辊的阻力降低了28.66%。

A finite element code ABAQUS/Explicit was used to model three-dimensional soil compaction process. Drucker- Prager Cap （DPC） model was used as soil constitutive model. The behavior of the soil-bionic press roller interface was investigated and compared with a conventional roller. Simulation results show that the artificial strain energy is approximately 0. 1% of the internal energy, indicating that hourglassing exerted very little influence on the simulation results. For the conventional press roller and bionic press roller, the relative error of traction resistance between the simulation and soil bin test results are 11.47% and 2.38% , respectively. The simulation results agree well with the experimental results. It proves that the finite element model is reliable. The Mises stress nephogram, the contact area between soil and press roller and the displacement nephogram are adopted to compare the simulation results of the two press rollers. The simulation results show that contact stress between the bionic roller and soil is significantly higher than that of conventional roller, which is beneficial for crushing clods. The contact area between bionic roller and soil is 79.05% lower than that of conventional roller, which is helpful to reduce soil adhesion. Also this result is proved by the soil bin test results, which shows that the bionic roller can reduce 52.78% of soil adhesion. Adjacent ridge structures of the bionic roller can properly constrain the flow of soil, thus avoiding the hilling phenomenon in compaction process. The two press rollers show little variance in vertical displacement and have similar compaction resistance, but bionic roller is more conducive to compact topsoil. The soil displacement in the direction of roller width caused by the conventional roller is greater than that of the bionic roller, which makes the conventional roller consume more power. The soil bin test results show that the bionic roller lowers the resistance by 28.66% as compared with conventional roller.