ABOUT DEVELOPMENT OF COMPUTATIONAL SCHEMES OF ADDITIONAL DEVICE ON A STRUCTURE, THAT ALLOWS FOR TARGETED CHANGES OF NATURAL FREQUENCIES TO PRESET VALUES

Abstract

For some elastic systems with a finite number of degrees of freedom of masses, in which the directions of mass movement are parallel, methods have been developed for creating additional constraints, the introduction of each of which specifically increases the value of only one natural frequency to a given value, without changing any of the other natural frequencies and any of the forms of natural vibrations. Methods have also been developed for creating additional kinematic devices, the introduction of each of which specifically reduces the value of only one natural frequency to a given value, without changing any of the other natural frequencies or any of the forms of natural vibrations. If it is necessary to aim at increasing the values of some natural frequencies and reducing the values of some others, then these requirements can be implemented by creating appropriate separate targeted constraints and separate targeted kinematic devices. If the operating conditions of the facility allow, then these individual targeted devices can be independently installed in the source system. The distinctive paper proposes a method for development of integrated (complex, unified) group targeted device that increases some intended natural frequencies to preset values and reduces other intended frequencies to preset values, without changing any of the other natural frequencies and any of the forms of natural vibrations. An algorithm for the creation of such a single targeted group device is proposed. It is shown that the group targeted device created in this way can be used in special cases both as a group targeted kinematic device and as a group targeted constraint. The initial probation (testing) of the algorithm was implemented with the use of the software products “SCAD” and “Lira”. Some special cases of development of computational schemes of such devices are considered.