斜向激振模式下振动轮的滞回响应特性分析

考虑物料在斜向激振模式下压实进程中的弹塑性变形,提出一种仅依据土壤特性参数的水平对称及垂直不对称滞回动力学模型。在一次近似的前提下,利用渐进法(krylov-ogoliubov mitropolsky,简称KBM)将非线性作用力线性化为等效刚度和等效阻尼,并推导出系统的频响方程及响应解。数值仿真结果表明,由于非线性滞回力作用,压实进程中系统出现"软化"趋势,振动轮波形发生畸变,稳态下水平方向上呈现只含基波和奇次倍谐波的响应谱,垂直方向上呈现含除基波外明显的各奇、偶次倍谐波的谱特征。土壤现场压实试验分析结果与仿真结果基本吻合,滞回响应特性的研究为压实工况的实时监测和提高压实性能提供了理论依据。

Movement and Heat Transfer of Particles in Inhomogeneous and Nonisothermal Rapidly Oscillating Fluid Flow

Based on the Krylov-Bogolyubov method of averaging the closed system of equations for particle motion and temperature in inhomogeneous rapidly oscillating velocity and temperature of fluid phase is derived. It is shown that the particle movement in a rapidly oscillating fluid velocity field occurs not only under the force of gravity and resistance, but also under force of migration. The migration force is the result of particle inertia and in homogeneity of oscillation of velocity field of the carrier phase. Effects of dynamic and thermal relaxation times of particle and gravity force have been studied. It is shown possibilities of accumulation of particles under the combined action of gravity and migration forces. For a linear dependence of the amplitude of velocity and temperature fluctuations of the fluid an analytical solution was presented. The analytical solutions have been found in good agreement with the results of numerical solution of system of equations of motion and heat transfer of particle.