GENERALIZED HIGH-ORDER ACCURATE NEWMARK METHOD FOR HEAD-DISK INTERFACE DYNAMICS IN MAGNETIC RECORDING TECHNOLOGY

The head-disk interface in disk drive has been modeled as a multi-degr ee-of-freedom system for mechanical performance studies and design opt imization. To simulate the dynamics of the modeled system, conventiona l Newmark method with delta > 1/2, alpha > 1/4 is usually applied. Thi s method introduces some algorithmic dissipation which is desired for eliminating high-frequency oscillation. However, this feature is acqui red at the cost of accuracy. In this paper, a generalized sub-stepping procedure is proposed to render Newmark method (delta = 1/2, alpha = 1/4) third-, fourth-, and fifth-order accurate while retaining uncondi tional stability and acquiring algorithmic dissipation. Detailed formu lations, the error and stability analyses are presented. The derived a lgorithm is used to calculate the responses of a slider applied for th e contact recording interface so as to evaluate its dynamics performan ce. The advantage of the sub-stepping procedure is that the improved a ccuracy is attained merely by one, two or three additional residual ev aluations, with no changes in the implementation of the underlying New mark method. Thus, it could be incorporated into existing finite eleme nt codes strightaway. In particular, little additional storage and no extra computations of high-order gradients are required as the convent ional higher-order accurate methods. The salient feature of the presen t method is that it generalizes the sub-stepping procedure and leads t o higher-order algorithm with controllable dissipation. (C) 1998 Elsev ier Science B.V. All rights reserved.