Abstract
This paper investigates statistical variations occurring in the dynamic characteristics of structures and the way to simulate the variation by using eigen properties. First, accelerances of about 100 steel-cans are measured and the statistics of the measured accelerances and the modal properties on some orders are evaluated. Next, a nominal FE model based on one of the steel-cans tested is built through the comparison with the modal properties determined by the experimental modal analysis. The modal properties such as natural frequencies and modal damping ratios are considered to have the uncertainty. The variations on natural frequencies and modal damping ratios of the measured accelerances for the 100 steel-cans are evaluated. It is observed that these distributions follow the normal distribution approximately. As a result, it is shown that the population of the accelerances calculated by the FE model under the normal distribution based on the identified distributions is similar with the measured accelerances. The other distributions for expressing the variations of modal properties are also discussed.
