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

1.三垫块滑块对微波度的跟踪特性分析及优化设计利用分布式空气轴承模型，数值研究了滑块设计参数对三块滑块对微波度跟踪能力的影响，阐明了三块块滑块的优化设计。2滑块-圆盘接触中粗糙度和半月面力的评估为了评估滑块-圆盘接触时表面粗糙度的刚度，我们建立了一个考虑整体变形的修正的Greenwood-Williamson(GW)模型。结果发现，只有当滑块与圆盘之间的距离大于凹凸体高度的平均值和均方根值之和时，由原GW模型计算的接触刚度才是有效的，接触区域的接触刚度可视为线性弹簧。3.2-近接触滑块摩擦振动的自由度分析为了研究近接触区域滑块的剧烈振动和着陆和起飞过程的迟滞行为，采用考虑弯月力和摩擦力的二自由度模型对滑块与圆盘表面的动态接触进行了数值计算。结果发现，滑块的剧烈反弹振动并不是简单的周期性振动，而是包含了许多频率。通过对滑块1 MHz以下振动的频谱分析，可以观察到许多超谐现象。这些分析结果与实验结果吻合得很好。

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.