Design of an impact excitation system for modal testing

Dynamic (vibrational) behavior of structures is critical to the functionality and performance of many systems. Although, numerous simulations are performed on sub-components of a system prior to fabrication and application, for reliable design and performance evaluation, the dynamic behavior of fabricated parts/structures should be accurately characterized though experimental techniques (modal testing techniques). 

In a nutshell, modal analysis is a process whereby we describe a structure in terms of its natural frequencies, damping, and mode shapes, which are the dynamic properties. In modal testing, the structure is excited at a particular point using mainly impact hammers or shakers. And the corresponding response is measured using sensors such as accelerometers or laser Doppler vibrometer (LDV). Using the measured response and the excitation data, the dynamic properties of the structure can be extracted. 

The easiest method of exciting the structure is to use impact hammers. However, this technique is a manual approach that introduces variabilities in impact location, impact orientation, and impact force magnitude/bandwidth. The aim of this project is to come up with a new excitation system to eliminate the need for a manual user to achieve repeatable vibration (modal) testing of structures in a fast manner.