Reciprocity in Experimental Modal Analysis

This paper deals with modal analysis and estimation of modal parameters of an analyzed structure. An aim of the paper is to verify one of four basic assumptions considered in modal testing. This property is reciprocity. Reciprocity means that the frequency response function measured between two degrees-of-freedom must be the same regardless of which degree-of-freedom is input or output. In the paper the experimental and numerical modal analysis of a cantilever beam are presented. There are described two experimental measurements focused on reciprocity of measurement process. Measured mode shapes are compared to each other using Cross Modal Assurance Criterion. The results of experimental and numerical modal analysis are compared to each other.