Structural damping optimization via non-obstructive particle damping technique

A passive vibration damping technique that is referred to as 'Non-Obstructive Particle Damping (NOPD)' is presented. The NOPD technique consists of making small diameter holes (or cavities) at appropriate locations inside vibrating structures and filling these holes to appropriate levels with particles which yield the maximum damping effectiveness for the desired mode (or modes). Powders, spherical shaped, metallic, non-metallic or liquid particles (or mixtures) with different densities, viscosities and adhesive or cohesive characteristics can be used.