Abstract
A method is proposed to modify a finite element model of a structure by using spring elements of adjustable stiffness so that the results of dynamic analysis by the model fit the experimental results obtained from a trial product. This adjusting modification realizes accurate prediction of the dynamic characteristics of structures proposed thereafter in the design stage to arrive at a final design in a short time. The adjustment can be performed based on the incomplete data on the dynamic characteristics of both the trial product and its model. Some examples of adjustment are presented to show that (1) the modification can be done by using the modal displacement of only the lowest few modes and of the selected points in the structure, (2) the result of modification approaches the exact model of an actual product by increasing the degrees of freedom of the original model and (3) the modified model can simulate the dynamic characteristics of structures more accurately than the original one.
