Dynamic characteristics of the spatial pipe system
by
Aurel Alecu
Politehnica University of Bucharest
Coauthors: Mihail Boiangiu, Victor Buracu

This paper is focused of the issue of calculating the frequencies and mode shape of the spatial pipe system. This method includes non-uniform parts of the system, the concentrated inertial systems, or other possibilities of support for this structure. All possible movements of the transversal section are taken into consideration (extension-compression, torsion, bending) and their interdependence due to the system’s spatial attributes. For a transversal section, a twelve component state vector has to be defined, and transfer matrix method has been applied. Supposing that for each movement an integer power series approximation (Frobenius method), the differential equations system for the coupled movements became a system with recurrent expressions between the coefficients of ascending power series in a matrix shape. From the power series’ coefficients for each movement, only twelve are independent from one another. Each coefficient’s influence is determined by an ingenious choice of the initial values. After the transfer matrix has been set, the problem of determining the systems’ characteristics has a classic solution. This method can be applied to a spatial pipe system for a nuclear energy plant.

Date received: April 13, 2008

Copyright © 2008 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caxc-34.