Modular server frame with robust earthquake retention

Abstract

Modular server frame with robust earthquake retention Adequate retention of computer systems during earthquake events is important because it can not only prevent human injury and potential system damage, but also ensure system availability by limiting to acceptable levels the transmitted accelerations to critical system components such as hard drives. This paper discusses the design of an IBM frame structure and related hardware, and the retention methods used, to provide a robust mechanical installation in both raised-and nonraised-floor environments, capable of surviving severe seismic events. The development of the frame structure and the retention hardware involves extensive earthquake simulation testing, in which the responses of the system under different earthquake test profiles are recorded and analyzed in both the time and frequency domains. Industry standards such as the Bellcore NEBS GR-63-CORE and IBM internal specifications are reviewed and compared, and the transient responses of competing frame designs subjected to various earthquake profiles are investigated to ensure compliance. Finally, the concept of modular design, in which various frame components are utilized to create a flexible family of frames, is discussed.

Seismic Testing and Analysis of Main Frame Computer Structure

“…As noted previously, the first mode frequency of the empty frame, without reinforcement brackets installed, was measured to be 3.4 Hz. Previous tests [1][2][3][4][5] recommend that the first modal frequency for an empty frame and a fully populated system should be approximately 7 Hz and 4 Hz, respectively. As a result, these reinforcement brackets are required [1][2][3][4][5].…”

“…Previous tests [1][2][3][4][5] recommend that the first modal frequency for an empty frame and a fully populated system should be approximately 7 Hz and 4 Hz, respectively. As a result, these reinforcement brackets are required [1][2][3][4][5]. Table 2 tabulates the acceleration responses of the frame at various locations when the frame structure was subjected to horizontal vibration from side to side (see Figure 10).…”

“…Adequate mainframe structure and retention of computer systems to the building floor are important to prevent human injury as well as prevent potential interruption of the mainframe computer's continuous operation. The development process of the frame's structure and its retention hardware involves extensive design efforts and analyses [1][2][3][4][5]. The test input profiles for analysis and testing employ industry standards (e.g., Telcordia NEBS GR-63-CORE) [6]) as well as IBM internal specifications [7].…”

“…The initial process step was to develop a frame structure that housed the subassemblies consisting of a central processing unit, input/output (I/O) unit(s), power components and other related hardware. To attach the frame structure to the concrete floor, a fixed frame tie-down was selected based on previous successful tests incorporating this method [1][2][3][4][5]. A current release of the ANSYS ® finite element analysis program was utilized to evaluate the frame's structural stiffness by estimating the modal frequency of the structure.…”