Improving the read/write performance of hard disk drives under external excitation sources based on multi-objective optimization

Hard disk drives (HDDs) are sensitive devices responsible for storing and retrieving digital information in computer systems and electronic products. In particular, HDDs of laptop personal computers (LPCs) are very sensitive especially in harsh mechanical environments. Accordingly, it is necessary to protect them against damages attributable to shock and vibration so as to reach better magnetic read/write performance. In this paper, the nonlinear multi-objective optimization method is utilized to enhance the passive control performance of rubbers through minimizing destructive effects of shock and random excitations. As a matter of fact, this investigation will focus on improving the shock and vibration isolation system with special emphasis on the role of rubber feet. A zero mean, stationary process with Gaussian distribution is applied to the base in order to consider effects of random excitation. Moreover, a half-sine pulse of acceleration is assumed as the base shock excitation. According to limitations of geometrical parameters and lumped modal parameters, twelve inequality constraints are presented. Modal parameters of rubber mounts and rubber feet are selected as design variables of optimization, and the multi-objective optimization problem is solved for three commercial cases of HDD by using non-dominated sorting genetic algorithm II (NSGA-II), which was proposed based on Pareto-optimality concept. Therefore, new characteristics of rubber mounts and rubber feet are recommended to be manufactured for the purpose of protecting HDDs against shock and random excitations.