ISSN   1004-0595

CN  62-1224/O4

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黏弹材料点接触时变与稳态问题的多重网格解法

Multigrid Methods in Solving Transient and Steady-State Viscoelastic Point Contact Problems

  • 摘要: 采用多重网格方法对黏弹材料在干接触状态下的时变和稳态点接触问题进行了数值求解. 时变问题主要包括黏弹材料静态蠕变问题和动态纯滚动时从发生接触至达到稳态的接触状态演变问题;稳态黏弹接触问题则主要为纯滚动达到平衡状态后的接触参数求解,对此提出微分形式的黏弹性变形公式使其计算效率提高至弹性变形的计算效率. 数值分析与计算结果显示:黏弹点接触问题主要由两个无量纲参数控制,即无量纲化速度参数Deborah数以及所用黏弹材料标准线弹性固体模型(Standard Linear Solid, SLS)中2个弹性极限的比例( E_\infty /E_0 ). 与弹性材料的瞬时响应特性不同,黏弹材料在变形以及变形恢复过程中呈现出一定的滞后行为,表现为滚动过程中接触区形状在出口处产生不同程度的收缩,且接触压力在入口处出现压力峰,起滚动阻力的作用. 该研究证明多重网格算法可以高效地解答三维时变与稳态黏弹接触问题.

     

    Abstract: Multigrid method is used to solve the viscoelastic point contact problems in this paper. The Standard Linear Solid (SLS) model is used to characterize the viscoelastic behavior of the substrate. Viscoelastic dry transient and steady-state models were proposed based on the differences of the time-dependent response of the viscoelastic materials. A new viscoelastic deformation modeling equation was derived for viscoelastic steady state model so that the efficiency of the computation of the viscoelastic deformation remains close to that of the elastic case, rather than being much more expensive owing to its time varying nature. For rolling contacts in steady state regime, the viscoelastic contact problem was dominated by two dimensionless parameters: the Deborah number which relates the relaxation time of the viscoelastic material to the characteristic time of the material passing through the contact, and the ratio of the two elastic limits of the SLS viscoelastic material. Asymmetric pressure distributions skewing towards the inlet side of the contact were obtained as a result of the time-dependent deformation behavior of viscoelastic materials.

     

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