Oscar Jaime Ruiz

Understanding the Dynamics of Contact Recording Head-Disk Interfaces

Contact recording is fast becoming an attractive alternative to conventional flying recording heads. For contact recording, a new design philosophy has to be developed based on good understanding of contact dynamics of the head-disk interface. We have developed an integrated approach to understanding these interfaces, where experimental results from friction and laser doppler interferometer measurements are modeled using modified air bearing codes. Important insights gained: 1) smaller contact pad size reduces friction and bounce, 2) rougher disk surfaces have lower friction and contact stiffness, and 3) pitch angle and lubricant lube thickness strongly influence damping of slider motions.Copyright

The past present roles of computer-aided engineering in DASD design

At the heart of todays computer-aided engineering (CAE) revolution is finite element modeling (FEM). This paper presents a brief history of how FEM simulations interact with and have significant impact on the design process of storage devices. The discussion is limited to structural static and dynamic effects on head/disk assemblies (HDAs) and components. FEM is integral to the design process; it is primarily a predictive/diagnostic design tool that provides engineers with detailed information on the performance of a design. FEM is most effective during the concept phase, where it can sort out many performance issues before the design parameters are constrained. Also, FEM can help to optimize critical structures within the system. As a diagnostic tool, FEM supplements testing by predicting in advance the properties and behavior of the device. A three-piece suspension design is presented as an example of how FEM and design work in harmony. An FEM of the entire structure was built to verify design and to fine-tune dimensions. Areas that required reinforcement and frequencies that seemed too low were identified, and the structure was modified. This process was repeated several times until the design satisfied the requirements. In addition to the suspension design example, a thermal deformation problem with a 3.5-in. actuator comb assembly is discussed.