DEVELOPMENT OF MEASUREMENT EQUIPMENT OF MEMBRANE STRESS FOR MEMBRANE STRUCTURES USING WHITE NOISE SOUND WAVE

—Improvement of Measurement Equipment, Verification Experiment and Practical Measurement of Actual Suspension Membrane Structure—

Abstract

A new method has been proposed by authors to measure membrane stresses in two different directions separately, where instead of measuring the membrane stresses directly, the natural frequencies of the membrane within fixed rectangular region resonated by white noise external excitation with the frequency of 0 to 500Hz induced by sound is utilized. The new method makes use of the resonance phenomena of the membrane, where the effect of added mass of surrounding air was found not to be able to ignore for high accuracy measurement, and theoretically evaluated by using an equivalent circular plate. In this paper, not only the process of the equipment improvement toward high accuracy and the result of experimental test on every process to verify its accuracy, but also the experimental test of actual suspension membrane structure are presented.