Experimental modal testing using pressurized air excitation

Abstract

Non-fixed excitation methods are often needed in modal analysis (for instance in quality control applications). Several non-fixed methods exist to perform this task: impact hammer, electro-magnetic, acoustic and laser excitation. In this article the use of pneumatic excitation using an impinging air jet is proposed as an alternative. Through a detailed experimental study it is shown that forces up to 0.6 N can be attained, while with the current valve technology one can excite up to 1 kHz. Two application cases are considered: a modal analysis of a cantilevered beam and a vibration test of a hard disk.