Sensitivity analysis of frequency response function en- velopes of mechanical structures with interval uncertain- ties

This paper introduces an interval sensitivity procedure that calculates the sensitivity of the envelope response function in the outcome of the interval FRF analysis to each individual interval model uncertainty. The procedure focuses on the calculation of the sensitivity of the bounds defining the FRF response range to the width of each individual uncertain input parameter. The approach differs from the classical sensitivity analysis in the fact that it does not calculate local changes on the output resulting from local changes in the input. The interval sensitivity result describes the change of the response interval width, taking into account a change in the parameter interval width. The paper first introduces the concept of interval sensitivities. It then describes the theoretical background of the interval FRF procedure, on which the interval sensitivity analysis is applied. Finally, the method is illustrated on a numerical example.