ABOUT AN INVERSE EIGENVALUE PROBLEM ARISING IN VIBRATION ANALYSIS

The problem of the best approximation for a given real matrix in the F robenius and the weighted Frobenius norm on real symmetric positive se midefinite matrices under the given spectral constraints is considered . Such a problem is related to the frequently encountered engineering problem of a structural modification on the dynamic behaviour of a str ucture. Necessary and sufficient conditions are obtained for the solub ility of the problem. A numerical algorithm is suggested. Two numerica l examples are given.