Optimal parameters for experimental dynamic testing

Modal testing is normally performed by experienced test engineers and technicians. On the base of their expertise, they define the best set up for extracting all the requested information from a vibrating structure. They decide how to suspend it and where, how many sensor and which kind of exciters have to be used and where they have to be placed, they select the best acquisition parameters and so on. In most of the cases this sensibility leads to excellent results, still sometimes, once the measurements are done, the quantity and the quality of the acquired data is not sufficient for the tasks ahead. Several parameters have been defined in the previous years to help the experimenters defining the best set-up. Often the interpretation of these indexes is subjective and applicability is limited due to the test pieces’ geometry. This paper presents two new pre-test indicators focused on the optimal sensor and exciter positioning that reduce the personal intervention. These indexes provide a large spectrum of solutions, supplying more possibilities for the experimenter to acquire a complete and reliable database.