Introduction: In the dynamic world of vibration testing, the foundation upon which a vibration table rests is more than just a support structure—it is a critical component that influences the efficiency and performance of the entire system. This article explores the significant role and specific requirements associated with vibration table foundations.
I. Foundation as an Energy Absorber: At its core, the foundation of a vibration test table serves as a crucial energy absorber during vibration tests. Following Newton’s first law, the force applied to the dynamic load of the vibration test table is met with an equal and opposite reaction force. This interplay propels the dynamic load upward, inducing controlled vibrations, while simultaneously exciting the static load mass downward.
II. Isolation Mechanism with Air Springs: The use of vibration isolating air springs between the electromagnetic vibration shaker body and its supporting structure enhances the isolation mechanism. The resonant frequency (fn) of the mass-spring system composed of air springs and their load is typically in the range of 3-5Hz. When the test frequency (fs) exceeds three times the table body’s resonant frequency (fs≥3fn), the air springs exhibit effective damping. In scenarios where vibration tables operate in the 5-10Hz frequency range, extensive ground-based isolations are unnecessary, allowing direct placement on smooth cement surfaces.
Stay tuned for the second part of this series, where we delve into how foundations are instrumental in improving the low-frequency performance of vibration test sytstems.