Influence of Attached Body on the Frequency and Modes Free Vibrations Cylindrical Shells

The paper uses the method of final element in linear function in MSC «Nastran» software complex to study the influence of the inertial properties of the added rigid body-locking rod, which is directed towards mid-surface in normal, by changing its length and the relative mass value on its own dynamic performance of thin circular cylindrical shell. The findings are compared with the case vibration of the shell, carrying the added mass and with the well-known analytic solutions. The mode state (MS) of the construction made the shells with added rod has been studied. The MS of the construction depends on geometrical and physical parameters and on the kind of vibrational forms of the body connected to it have been identified. The rod connected to the shell expands the range frequency of vibration in relation to the shell, carrying the added mass. The influence of its inertial properties with increase of length of the body connected to shell (distancing center of mass connected rod from the shell) had become increasingly important. However, the influence of inertial properties connected with increase in the size of the body accession to shell is decreasing. The ranges, when inertia of jointed body may be disregarded, were presented.