DEVELOPMENT OF COMPUTATIONAL SCHEMES OF GROUP TARGET CONSTRAINTS FOR SOME ELASTIC SYSTEMS

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 intro-duction of each of which purposefully increases the value of only one natural frequency to a given value, while not changing any of the other natural frequencies and not one of the natural modes (forms of natural oscillations). If it is necessary to increase the values of several natural frequencies in a targeted manner, then this requirement can be implemented by creating an appropriate number of separate targeted constraints. The computational scheme of each of the individual targeted constraints should include racks installed at the nodes of mass application and directed along the trajectory of their movement. In some cases, individual targeted constraints can be independently installed on the original (initial) system. In most cases, on the basis of individual targeted constraints, a computational scheme of a united group targeted constraint is developed, which increases all the intended frequencies to the set values, without changing any of the other natural frequencies and not one of the natural modes. The distinctive paper is devoted to a method for forming a matrix of additional stiffness, which corresponds to a group targeted constraint. The requirements for those targeted constraints, on the basis of which a group targeted constraint is formed, are formulated. An algorithm for the development of group targeted constraint is proposed with allowance for the formulated requirements.

Keywords

• atural frequency, natural mode, targeted constraint, group targeted constraint, |additional stiffness coefficients