Accession Number : AD0479704

Title :   RESPONSE OF CYLINDRICAL SHELLS ENCOMPASSED WITH ISOLATION MATERIAL TO A PLANE PRESSURE PULSE.

Descriptive Note : Final rept. 1 Jul 63-1 Jun 65 on Phases 1 and 2,

Corporate Author : IIT RESEARCH INST CHICAGO IL

Personal Author(s) : Costantino, C. J. ; Marino, R. L., Jr.

Report Date : FEB 1966

Pagination or Media Count : 234

Abstract : Research was conducted to determine changes introduced by an encompassing layer of isolation material (closed cell polyurethane foam) in the response characteristics of a cylindrical shell tunnel model buried in soil and subjected to a plane pressure pulse. The response characteristics of nine different models, each having a steel shell 5 inches in diameter by 42 inches long were experimentally determined for a 12-inch depth of burial in dense Ottawa sand in the IITRI 4-foot-diameter dynamic soil loader. The pressure pulse applied to the soil surface throughout the program had a rise time of approximately 6 milliseconds and a peak of approximately 560 psi. The model parameters studied include shell stiffness, foam thickness, and foam crushing strength. The presence of an isolation layer produces large reduction in the shell membrane forces in all instances and large reductions in shell bending moments in those instances (stiff shells) where significant moments are present with no isolation material. If the foam strength is such that a significant amount of crushing occurs, then shell deformations are also substantially reasonably accurate predictions of shell response. (Author)

Descriptors :   *UNDERGROUND STRUCTURES, SHOCK RESISTANCE, CYLINDRICAL BODIES, ATTENUATION, VIBRATION ISOLATORS, SOIL MECHANICS, DYNAMICS, DEFORMATION, SOILS, STRESSES, STRAIN(MECHANICS), TRANSDUCERS, OSCILLOSCOPES, FOAM, CRUSHER GAGES, MODEL TESTS, MATHEMATICAL ANALYSIS, ISOCYANATES, PLASTICS, PRESSURE, STIFFENED CYLINDERS, ELASTIC SHELLS, MECHANICAL WAVES, SHELLS(STRUCTURAL FORMS), PERFORMANCE(ENGINEERING), PROTECTIVE COVERINGS, MATHEMATICAL MODELS, MATHEMATICAL PREDICTION, FLOW CHARTING.

Subject Categories : Structural Engineering and Building Technology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE