Accession Number : AD0282172

Title :   Progress Report Number 3, 1 April-30 June 1962.

Descriptive Note : Progress rept. no. 3, 1 Apr-30 Jun 62.

Corporate Author : TEXAS UNIV AUSTIN DEFENSE RESEARCH LAB

Report Date : 15 JUL 1962

Pagination or Media Count : 1

Abstract : Recalibration of the mechanical impedance head is described. A sensitivity of 56.1 db re 1 gram for the instrument with 75 ft of cable was found. Measurements of mechanical mobility parameters of a special pressure balanced pipe coupling are described. Parameter values obtained for coupling internal pressures of 0 to 75 psig were substantially in agreement. Input mechanical mobility of a flanged metal pipe and weight structure to axial forces has been calculated and measured. Results of the measurements were in close agreement with calculated values, although vibration of the pipe produced large differences at particular frequencies. Longitudinal wave propagation velocity in copper-nickel pipe has been found from measured values of the input mechanical mobility of a 12 ft length of the pipe. A value of 13,382 ft per second was found. The freefield velocity for longitudinal waves in this material is 13,610 ft per second. Transmissibility of the special pipe coupling attached to the assumed pipe-weight load structure has been computed and also measured directly. Differences in transmissibility measured and calculated are attributed to errors in measurement of mobility parameters of the coupling. The measured parameter values were used in the transmissibility calculations. (Author)

Descriptors :   (*ACOUSTIC FILTERS), (*ACOUSTIC IMPEDANCE), (*LIQUIDS), WAVE PROPAGATION, SOUND, PRESSURE, MEASUREMENT, HYDROPHONES, HOSES, PIPES, VIBRATION, VIBRATION ISOLATORS

Distribution Statement : APPROVED FOR PUBLIC RELEASE