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How Vibration Control in Data Centers Can Protect Our Modern Lives
Vibration Isolation Systems are used on the Mobile Launch Platform to mitigate vibrations from the launch and protect important electronic equipment from damage.
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Vibration Isolation Systems are used on the Mobile Launch Platform to mitigate vibrations from the launch and protect important electronic equipment from damage.
Vibration Isolation Systems are used on the Mobile Launch Platform to mitigate vibrations from the launch and protect important electronic equipment from damage.
Application of Taylor Devices dampers in a steel frame structure building.
The two frame office towers, constructed in the 1970s per the 1967 edition of the UBC, use perimeter reinforced concrete moment frames to resist seismic loading. The buildings are rectangular in plan and have certain characteristics that adversely affect their seismic performance, in particular the presence of a soft-story response at the first floor (approximately 50% taller than typical floors), and limited ductility typical of buildings of that era. Risk analysis showed that for the towers the PML exceeded 20%. Nonlinear response history analysis (NLRHA) of the towers was conducted and showed that in the existing configuration, the story drift ratios (SDRs) at the first floor exceeded 2%, shear hinging of the first floor beams was expected and that the SDRs would need to be reduced to approximately 1.4% for the first floor to limit the extent of nonlinear response. Seismic retrofit included addition of 300-kip viscous dampers in both directions to the first floor of the building.
A roof isolation system is proposed as a means to reduce the detrimental effect of earthquakes in buildings. This roof isolation system entails the insertion of flexible laminated rubber bearings between a building’s roof and the columns that support it and the addition of viscous dampers connected between the roof and the rest of the building. The properties and dimensions of the rubber bearings and viscous dampers are selected in a way that makes the roof, bearings, and dampers form a highly damped vibration absorber. Presented also is a comparative study with a simple five story steel building under a strong earthquake ground motion that is carried out to assess the effectiveness of the proposed system. In this comparative study, it is found that the roof isolation scheme reduces the floor displacements and interstory drifts of the analyzed building by as much as 83 percent. On the basis of these results and in view of its simplicity, it is concluded that the proposed roof isolation system has the potential to become a practical and effective way to reduce earthquake damage in buildings.
This paper provides a literature review on the application of base isolation and supplemental damping systems for seismic protection of wood structures. The review reveals that both elastomeric bearings and sliding bearings have been considered for implementation within base isolation systems of wood framed buildings. In addition, friction dampers, viscoelastic dampers, hysteretic dampers, and fluid viscous dampers have been considered for implementation within the framing of wood buildings. Although there are a number of impediments to the widespread implementation of such advanced seismic protection systems, the reviewed literature clearly demonstrates that advanced seismic protection systems offer promise for enabling light framed wood structures to resist major earthquakes with minimal damage.
The Sperry Marine MK 49 Ship’s Inertial Navigation System (SINS) is now in production for marine surface and subsurface applications. This system has been selected as the standard NATO SINS equipment and is the only marine inertial navigator which utilizes ring laser gyros. In order to serve the NATO community, the system must withstand a variety of shock stimuli (STANAG 4141, STANAG 4142, BR3021, etc.). Sperry Marine has shock hardened the system enclosures and developed a shock isolation system for the Inertial Measurement Unit (IMU) using tension compression liquid spring/dampers in a hexapod configuration. This isolator assembly provides the shock attenuation and precision angular alignment return ability that is needed to meet the above specifications. This paper addresses the design process to shock harden the IMU and presents experimental results.
The Taylor Devices self-centering hexapod mount provides MIL-S-901D shock protection for the Litton Marine Systems MK27F Attitude and Heading Reference System (AHRS). This new Reference System satisfies stringent military shock and vibration requirements. Unlike Ring Laser Gyro (RLG) which have low fragility levels (Max 50 g), the LN200 Fiber Optic Gyro Assembly can be exposed to levels as high as 90 g. This paper addresses the shock transient mitigation for shock requirements specified by MIL-S-901D. Comparisons between predicted and measured response are provided for a single strut as well as the fully shock isolated platform. Analytical and experimental results are presented to demonstrate the effectiveness of the MK27F Shock Absorber basic design for MIL-S-901D LWSM and predicted response is also presented for the floating platform Heavy Weight Shock Machine (HWSM).
This article appeared in Special Operations Technology magazine. It provides a very complete explanation of the Taylor Devices isolated seat for the Navy, complete with many photos. The article also includes the experiences of the seat occupants under high speed ocean travel.
This paper summarizes a feasibility study for implementing seismic protective systems into high tech industrial structures in which costly vibration sensitive facilities are housed. Micro-vibration control of an IC fab is essential for optimum yield of reliable chip products. This paper describes the micro vibration analysis and measurement of a test structure before and after the incorporation of Seismic Protective systems. Based on the study, it is found that the incorporation of viscous dampers both enhances seismic safety and also minimizes the micro vibration of the structure. Viscous damper seismic isolation is the most promising method to achieve the “fully operational” seismic performance level of an IC fab.