Several international evaluation methods of vibration, ISO26311985, ISO26311997，BS68411987 and Absorbed Power, are introduced in detail, and their characters are summarized. The present status of research on evaluation methods of vibration is analyzed, and the present status of research on human response characteristics to vibration is summarized. It is shown that the human response to vibration is very complicated and influenced by human posture, human weight and vibration magnitude etc. So, searching for more suitable and scientific evaluation methods may become a hot research focus is the area of vibration evaluation. According to domestic research in this area, some suggestions are presented, such as updating the national standards, measuring the human response to vibration and carrying out fundamental research etc., in order to establish an evaluation method of vibration which is suitable to our Chinese.

Vibration analysis of beams with sandwich constrained layer damping treatment is extended to the case where the structure is covered by multiple standoff constrained layer damping patches. The Maxwell model, assumed-mode method, finite element theory, energy-based approach and Lagrange equation are used to derive the equations governing the vibration displacement response of the system. Parametric studies are performed with the established analytical approach to study the effects of double patches with different thickness. That appears that the appropriate standoff layer thickness can achieve better damping.