One of principal goals of structural analysis is to formulate a reliable analytical model of a structure. Reliable model means the analysis results could be verified experimentally. As the structural analysis programs are widely used, finite element modeling and computerized structural analysis are heavily relied on in the design and development of engineered structures. But this model does not initially produce natural frequency and mode shapes which concur with actual test. It is due to structural uncertainty (generally speaking) which is defined to be the difference between that which can be predicted based on analytical model and analysis, and that which we might physically observe.
Much effort has been devoted to the quantification of structural uncertainty. But even if all sources of uncertainty could be identified and appropriately quantified, the computational task of combining them, source by source and element by element, would be staggering. This paper describes a practical method which is formulated for systematically using experimental measurement of the natural frequencies and mode shapes of a structure to modify stiffness and mass matrix of a finite element model. Through the modification process, which need experimental data, finite element model does remain consistent.
The objective of this study is to propose a general method which will identify a finite element model of a structure capable of providing modal characteristics which concur with those in test.