Design and evaluation of multi-axis vibration shaker concepts

Elastic bodies exhibit structural resonance and mode shapes at various natural frequencies. In order to avoid structural overloads and equipment malfunctions, elastic systems, mechanical and/or electrical must be evaluated and tested for their performance over the entire frequency range of their operations. Shaker systems replicate the dynamic loads encountered in a field environment, and are used for vibration testing of elastic structures. Such vibration testing ensures the reliable performance of the final product; The objective of this research project, sponsored by the Army Research Lab (ARL), is the design and Finite Element evaluation of a new multi-axis shaker system, which will be used to test and improve the performance of mechanical and electronic components exposed to severe dynamic loaDing The new shaker system should meet three major design specifications. One, the system should have six degrees of freedom. Two, the system must work in a frequency range from 10 Hz to 3,000 Hz. Three, the system should be sturdy enough to carry payloads up to 25 lbs; In order to develop a sound design methodology, theoretical performance predictions based on finite element analysis were compared with experimental records from an existing smaller shaker system. Structural modifications aimed at improving shaker characteristics were implemented and the performance of the modified shaker was tested experimentally. The predicted and actual dynamics of both small shaker systems were found to agree well in terms of predicting resonant modes and frequency response spectra.