The inverse problem of determining the weight of three intermediate masses on a uniform beam from the
known three natural frequencies has been solved. The performed numerical analysis allows restoring the
value of only the second mass in a unique way. The inverse problem of determining the weight of three
intermediate masses has been solved uniquely except in the case when the first and the third masses are
located geometrically symmetric relative to the middle of the beam. The hybrid algorithm for the unique
solving inverse problem of determining the weight of three intermediate masses has been developed. The
first three natural frequencies of the beam are calculated numerically by using the Maple computer package.
Analytical relations between the masses are found.
