Analysis of Dynamic Contact Behavior and Optimum Design Condition of a Slider in Near-Contact regime

1.采用分布式气轴承模型，数值研究了滑块设计参数对三垫滑块对微细波跟踪能力的影响，明确了三垫滑块的优化设计为了评估滑盘接触中表面粗糙度的刚度，我们建立了一个包含体变形的修正Greenwood-Williamson （GW）模型。结果发现，原GW模型计算的接触刚度只有在滑块与盘间距大于粗糙高度均值与均方根之和时才有效；3.2近接触状态下滑块摩擦振动的2-DOF分析为了研究滑块在近接触状态下的剧烈振动和着陆和起飞过程的滞回特性，采用考虑半月板力和摩擦力的2-DOF模型，对滑块与圆盘表面的动态接触进行了数值计算。结果表明，滑块剧烈的弹跳振动不是简单的周期性振动，而是包含多个频率。从滑块振动到1mhz的频谱分析中，我们可以观察到许多超谐波。分析结果与实验结果吻合较好。

1.Analys of Tracking Characteristics and Optimum Design of Tri-Pad Slider to Micro-Waviness We numerically investigated the effect of slider design parameters on the tracking ability of a tri-pad slider to micro-waviness using the distributed air bearing model and clarified optimum design of tri-pad slider.2 Evaluation of Asperity Contact and Meniscus Force in The Slider-Disk ContactIn order to evaluate stiffness of surface roughness in slider-disk contact, we developed a modified Greenwood-Williamson (GW) model including bulk deformation. As a result, we found that the contact stiffness calculated from the original GW model is valid only when the spacing between slider and disk is larger than the sum of mean value and rms value of asperity height, and that the contact stiffness in the contact regime can be regarded as linear spring.3.2-DOF Analysis of Friction-Induced Slider Vibrations in a Near-Contact ReguneIn order to investigate the severe slider vibrations and hysteresis behaviors of touch down and take-off processes in near contact regime, we numerically calculated the dynamic slider contact with disk surface by using the 2-DOF model considering the meniscus force and friction force. As a result, we could find the severe bouncing vibration of the slider is not simply periodic but contains many frequencies. From spectrum analysis of the slider vibrations up to 1 MHz, we can observe the many super harmonics. These analytical results agree well with the experimental ones.