Line Modification of Continuous Vibratory Systems

The power of the procedure lies in the reanalysis of large continuous systems when local modifications or re-sizings are made. The example problems demonstrate that the analyst chooses the degree of approximation by the number of normal modes selected to represent the continuous system. If very few modes are used, inaccuracies can be expected in the solution, but may be reduced by selecting more modes. Currently, the procedure is being extended to include area modifications. For example, an area stiffness modification with an infinite magnitude may represent a clamped edge. The stacking of systems can permit one to save computer time, if a complex structure can readily be broken into a number of simple components. This permits an analysis similar to component mode synthesis techniques.