Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Mechanical Engineering (MS)

Administrative Home Department

Department of Mechanical Engineering-Engineering Mechanics

Advisor 1

Gordon Parker

Committee Member 1

Jason Blough

Committee Member 2

Shangyan Zou


Equipment whose performance degrades when exposed to base vibration is often deployed in vibration-rich environments. Using 3D printers in mobile applications, such as vehicles and ships, are typical examples where the extruder and bedplate are easily excited by base vibration. A versatile active vibration isolator is considered in this thesis constructed using a voice coil actuator and a laser displacement feedback sensor to achieve a wide range of dynamic response characteristics, including negative stiffness. This approach permits transmissibility shaping to meet band-limited base isolation requirements without active damping vibration control. A combination of simulation and hardware validation is used to illustrate the approach, including a detailed calibration process for its voice coil as a control actuator. A 3D printer, mounted to a shaker, is used for final performance evaluation. A negative stiffness control strategy was implemented to shift the isolator’s resonance away from the excitation band. Part quality, measured by surface roughness, increased by 27.8% at the printer’s resonance of 4.75 Hz when using the negative stiffness control strategy. Since the system uses an active approach to modify the isolator’s dynamics, a wide range of isolator designs can be achieved besides negative stiffness. While the active isolator can be used for fielded applications, it’s perhaps more helpful for efficiently assessing competing passive isolator designs before creating prototypes.