On optimal design of HDD suspension using topology optimization

This paper explores the use of topological optimization to systematically design suspensions for hard disk drives (HDD). The design problem is posed as a material distribution problem, which varies spatial thickness of suspensions so as to enhance their dynamic performance. Due to the requirements for specific motion characteristics, suspensions are designed to have higher torsional and lateral frequencies while maintaining an adequate but not too high frequency for transverse bending. The torsional and lateral frequencies are generally higher in order than the transverse frequencies. Due to their non-convex nature, the optimizations of higher-order frequencies were proven to be more difficult than that of the fundamental frequency. To tackle the problem, present work adopted mode-tracking techniques, and attempted two different optimization algorithms to solve the design problem. With reference to the topological results obtained, it is found that the implementation based on sequential quadratic programming (SQP) performed better than that based on optimal criteria (OC). It was also found that the present design method could tremendously improve the dynamic performance of suspensions.