薄膜润滑中的应力偶效应

利用应力偶理论计算了薄膜润滑的膜厚特性.计算结果表明:应力偶的作用相当于增加润滑剂粘度,其可以增加油膜厚度,提高承载能力;同时应力偶作用依赖于油膜尺寸,润滑油膜越低,其影响越明显.

计入应力偶效应和空化效应的滑动轴承热流体动力润滑数值研究

基于应力偶理论和Elrod空化算法建立了滑动轴承热流体动力润滑数学模型，数值求解了应力偶流体的Reynolds方程、油膜能量方程及轴瓦热传导方程，考察了应力偶效应对滑动轴承热流体动力润滑性能产生的影响。结果表明：应力偶流体明显地提高了油膜压力，降低了轴承摩擦系数，同时也使端泄流量和轴承的温度场有所改变。

计入应力偶效应的滑动轴承热流体混合润滑研究

考虑含添加剂润滑油的应力偶效应,以倾斜轴承为研究对象,建立动载荷轴承热流体混合润滑模型,探讨倾斜角、表面粗糙度及应力偶效应等参数的耦合作用对轴承润滑性能以及润滑状态的影响规律。结果表明,应力偶效应减弱了热流体润滑轴承最大油膜压力增加的现象,且随着应力偶效应的增强,最大油膜压力的减小幅度逐渐增大;与牛顿流体相对,应力偶流体润滑下轴承的油膜温度降低,高温区域的油膜面积减小,轴颈附近油膜温度下降;增大轴颈倾斜角,流体内部的最大油膜温度增加;当应力偶参数较大时,倾斜角对油膜最大温度以及节点应力偶参数值的影响逐渐减弱;当应力偶参数较小时,增大表面粗糙度,混合润滑与流体动力润滑状态转变的临界转速增加,对应的最小摩擦因数增大。

Bending and Buckling of Circular Sinusoidal Shear Deformation Microplates with Modified Couple Stress Theory

The modified couple stress theory(MCST)is applied to analyze axisymmetric bending and buckling behaviors of circular microplates with sinusoidal shear deformation theory.The differential governing equations and boundary conditions are derived through the principle of minimum total potential energy,and expressed in nominal form with the introduced nominal variables.With the application of generalized differential quadrature method(GDQM),both the differential governing equations and boundary conditions are expressed in discrete form,and a set of linear equations are obtained.The bending deflection can be obtained through solving the linear equations,while buckling loads can be determined through solving general eigenvalue problems.The influence of material length scale parameter and plate geometrical dimensions on the bending deflection and buckling loads of circular microplates is investigated numerically for different boundary conditions.