Design of Modular Vibration Testing Equipment

Abstract

Vibration testing is used by introduction of a force function into system, usually with the use of a shaker or vibration testing machine. These induced vibrations, aid in the laboratory or production floor for a variety of things, proof of concept, standard assessment, fatigue testing, and evaluating performance. Electrodynamic shakers are well suited for most vibration tests and offer several advantages over alternative approaches. Resonance searches involve sine sweep to obtain a transfer function for evaluation of resonance characteristics, usually by a crank mechanism. Fatigue testing is an expensive and long term test, not being the most accurate one, due to the fact that the functioning of any machine is not repetitive nor reproducible regarding vibrations.Random vibration testing better represent real world data by providing statistical confidence with random time data that has an average targeted frequency content and amplitude over the duration of the test. By controlling amplitude and frequency, test data can be correlated to real world data sets.Throughout this paper we present the outlines for the design of a modular fatigue testing machine with pseudorandom vibrations. Due to the nature of the modular approach for our equipment, the rig can be appropriately configured to perform multiple laboratory tests.