Stress Gage Feasibility Analysis.
Technical rept. 5 Jun-15 Dec 70,
IIT RESEARCH INST CHICAGO ILL
Pagination or Media Count:
The feasibility of using buried fluid-filled spherical bladders initially pressurized to measure time history states of stress induced by High-Explosive Simulation Tests e.g., HEST test series is investigated. The first part of the study is concerned with obtaining both transient responses to step pressure inputs and steady state responses to harmonic pressure inputs. The type input waves considered are both plane dilatational and plane shear waves traveling through a solid elastic homogeneous medium. Solutions to these problems are presented for dilatational solid-to-fluid wave speed ratios ranging from 0.2 to 2.0 and from solid-to-fluid density ratios ranging from 1.5 to 2.7. The collection of these results give guidelines as to what type of fluid properties should be used in order to cut down the distortion of the input signal caused by mismatches in impedance between the fluid and transmitting media solid. The second part of the study is concerned with the inverse process of using the given i.e., measured pressure responses at one or more points in the fluid to determine what the state of stress in the free field input must have been. A scheme has been devised for separating the shear and dilatational stress component contributions to the total state of stress when the input is comprised of plane shear and plane dilatational waves.
- Soil Mechanics
- Test Facilities, Equipment and Methods