A Guide for the Design of Shock Isolation Systems for Underground Protective Structures

A Guide for the Design of Shock Isolation Systems for Underground Protective Structures
Author: Air Force Special Weapons Center (U.S.)
Publisher:
Total Pages: 447
Release: 1962
Genre: Blast effect
ISBN:
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This report reviews the major considerations relating to the design of Shock Isolation Systems for use in underground protective structures, emphasizing in particular those areas where special guidance is needed by the facility engineer. The motion of the ground due to nuclear blast, the interaction of the ground motion with buried structures, and the tolerances of typical facility equipment to shock are described and employed to establish the input and output requirements for isolation systems. Analytical methods for determining the dynamic responses of both linear and nonlinear isolation systems are summarized and, for several of the more commonly used configurations, the equations are reduced to simple form. The report suggests the use of the shock response spectrum in a unified approach to the specification of attenuation requirements, equipment shock tolerances and shock test machine selection.

DESIGN PROCEDURES FOR SHOCK ISOLATION SYSTEMS OF UNDERGROUND PROTECTIVE STRUCTURES. VOLUME I. STRUCTURE INTERIOR MOTIONS DUE TO AIR BLAST INDUCED GROUND SHOCK.

DESIGN PROCEDURES FOR SHOCK ISOLATION SYSTEMS OF UNDERGROUND PROTECTIVE STRUCTURES. VOLUME I. STRUCTURE INTERIOR MOTIONS DUE TO AIR BLAST INDUCED GROUND SHOCK.
Author:
Publisher:
Total Pages: 239
Release: 1964
Genre:
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The primary purpose of this report is to provide guidance for designers of shock isolation systems during the initial phases of design. Volume I presents methods for estimating appropriate free field waveforms and the influence of soil-structure interaction upon interior structure motion. The inherent error in shock isolation design is at least =20%; to reduce this, much more soil test data than is now available will be required. Further, based on purely theoretical arguments, shock isolation per se can be eliminated for much equipment used in hard installations. If isolators are required they should be designed as low frequency systems that impose one g acceleration on the isolated equipment. Increase of the acceleration to be tolerated by the equipment will, in the great majority of instances, reduce neither the rattle space required nor the isolator cost. Methods for making the necessary computations are given.

Design Procedures for Shock Isolation Systems of Underground Protective Structures. Volume V. Response Spectra of Multi-degree-of-freedom Elastic Systems

Design Procedures for Shock Isolation Systems of Underground Protective Structures. Volume V. Response Spectra of Multi-degree-of-freedom Elastic Systems
Author: N. M. Newmark
Publisher:
Total Pages: 126
Release: 1965
Genre:
ISBN:
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A discussion is presented of maximum response for multi-degree-of-freedom elastic systems considering five-degree-of-freedom systems in some detail, with some results for ten-degree-of-freedom systems and other systems for which data are available in the literature. Included are tabulations of response data computed from step by step integration of the equations of motion for five different forms of ground excitation on a number of systems having varying parameters of mass and stiffness distribution. The results are compared with the modal responses for the same systems, and general rules are developed for comparing the true responses with various combinations of the modal response data. Consideration is given to treatment of a multi-degree-offreedom system as a continuous shear beam, and some generalizations are drawn from the study which enable a better interpretation of the results of the specific data tabulated in the report. Some suggestions arising from the studies reported in Vol. IV are made to take into account the behavior of multi-degree-of-freedom systems in the inelastic range. (Author).