Evaluation of degradation of bricks using FRF

The knowledge of the dynamic state and structure of system allows to describe its behavior, and allows a model of the system behavior in the function of dynamic evolution time, based on the model of the technical state symptoms growth. Most often, there are no known equations describing behaviors of the system in the function of dynamic evolution time, which accounts for the need to apply new tools to examine the dynamic state. In this article authors shows chosen problems of technical state diagnosis with the use of identification and technical diagnostics methods such as experimental modal analysis. Relations between methods of dynamic state evaluation and methods of technical state evaluation were indicated. Example modal analysis results illustrate the complexity of projecting dynamic state researches into diagnostic researches of state evaluation.