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A Study Of Thermoacoustic Oscillations At Elevated Static Pressures, Michael Einar Berger

Mechanical Engineering ETDs

An experimental investigation was conducted to determine the effect of high static pressure on a closed thermoacoustic sound generator.

The theory for thermoacoustic oscillations is reviewed and analyzed for the case of elevated static pressure. Design equations for high internal pressure oscillators are developed from the principles of dimensional analysis, and a general de­sign equation is proposed.

A closed double-end thermoacoustic oscillator was designed to withstand high temperatures and pressures and was used in the experimental investi9ation. Both air and helium were used as the working gases.

The results of both the theoretical and experimental investigations show that acoustic sound-pressure …

Measurement Of Deformations An A Large Displacement Gradient Field, Lowell P. Martin

Mechanical Engineering ETDs

A summary of the general kinematical theory of finite deformations is presented together with analyses of the specific deformations of sim­ple shear, bending of a block and bending of an initially curved cuboid.

The moiré fringe equations for large homogeneous deformation are developed. The extension to the nonhomogeneous case is presented and specific analyses are given for the deformations noted above. The moiré theory is combined with the results of the large deformation analyses.

Theoretical results are verified by the study of geometrically produced moiré patterns, and by actual experiments conducted on syn­thetic rubber specimens. The experiments included the deformations …

Stress Fluid In The Vicinity Of A Crack, Alfred S. Arcache

Mechanical Engineering ETDs

The purpose of this investigation was to apply the logarithmic hypothesis of the plane elastic dislocation theory to approximate a plane fracture problem. The region of study is essentially elastic except for a very small region in the neighborhood of the crack which is at some undefined plastic state. The model is a large, thin plate, tensile specimen bounded at the interior by a circular hole from which two stable natural cracks are originated. The experimental model was developed by Ju and Shafer, who also obtained the dislocation function along the crack used in the analysis.

The present fracture analysis …

A Three-Component Force Transducer For Monorail Rocket Sleds, Vincent Warren Gorman

Mechanical Engineering ETDs

A three-component force transducer which permits measurement of the vertical force, the cross-track force, and the roll moment about an axis parallel to the track was developed for use on monorail rocket sleds. For this force system it was found that the maximum allowable load for both the vertical and cross-track components was approximately 28,000 pounds, and the maximum allowable roll moment was approximately 45,500 inch-pounds. The transducer, mounted between the slipper and sled, uses strain gages as component sensing elements. The strain gage bridges were statically calibrated for each component of load the transducer was designed to measure. In …