THE STRUCTURAL MODIFICATION INVERSE PROBLEM - AN EXACT SOLUTION

This paper deals with the problem of structural modifications. Required are the modifications needed in order to reallocate eigenvalues and specify eigenvectors. A theory is developed to show how the necessary mass and stiffness modifications can be computed using modal test results only, even when only a partial set of eigensolutions is available from such tests. The applied modifications are constrained in a way to force the selected number of eigensolutions to reside in the known subspace spanned by the original modal vectors, thus circumventing the problem arising from the truncation of the modal set. The paper includes a wide range of examples demonstrating the theory. These range from simple tutorial cases to more realistic ones involving continuous elements. © 1993 by Academic Press, Limited.