振动压路机的一种非线性动力学建模与仿真

根据压实作业的实际情况,建立了可以反映土壤弹塑性变形和振动轮跳振的不同压实阶段特点的土壤非线性力学模型。一次近似的前提下,利用谐波线性化方法将滞回非线性力线性化为等效阻尼和等效刚度。通过数值仿真,对振动压路机-土壤系统的动力学特性进行了研究。压实前期土壤处于弹塑性变形阶段,振动轮与土壤保持接触;压实后期随着土壤密实度的增大,振动轮发生跳振,系统产生亚谐波振动,一定条件下出现混沌,合理地调整激励频率和激励幅度则可以有效地抑制振动轮混沌。

Nonlinear Dynamic Modeling and Simulation of Vibratory Roller System

According to the experience of vibratory compaction, a nonlinear soil dynamic model was built. This model represents the dynamic characteristic of different soil compacted process including elastic-plastic nonlinearity and jump vibration. Based on the first order approximation, the equivalent damping coefficient and equivalent stiffness coefficient was deduced through the harmonic linearization method. By means of numerical simulation, the dynamic characteristic of roller-soil system was studied. During the beginning of vibratory compaction, soil represents elastic-plastic characteristic and the roller keeps coupling with soil. During the ending of vibratory compaction, density of soil increases and sub-harmonics may occur. When roller takes a jump vibration, chaos motion could be induced. Adjustment of excitation amplitude and excitation frequency could availably restrain the jump vibration and chaos motion of roller.