Modal truncation vectors and periodic time domain analysis applied to a cyclic symmetry structure
Abstract
A finite element analysis was performed to assess the vibration response of a cyclic symmetric rotating turbopump impeller to a periodic time domain triangular pressure pulse loading. A summary of the cyclic symmetry methodology and cyclic symmetry boundary conditions used in the analysis is given. Two new analysis algorithms that were applied for the response analysis are detailed. The first algorithm involves appending 'modal truncation' vectors to the eigenvector set which, with the retained eigenvectors, will completely represent the spatial portion of the dynamic loading. This algorithm is applicable to any type of modal response analysis such as time domain, random, harmonic or shock spectrum. The second algorithm is a time domain response analysis method as opposed to the frequency domain analysis method for the solution to an arbitrary periodic time domain loading. The modal truncation vectors with the time domain solution method results in a complete representation of the applied dynamic loading in both the spatial and time domains for the dynamic response analysis.
 Publication:

Computers and Structures
 Pub Date:
 November 1992
 Bibcode:
 1992CoStr..45..685D
 Keywords:

 Cyclic Loads;
 Dynamic Loads;
 Eigenvalues;
 Finite Element Method;
 Pump Impellers;
 Vector Analysis;
 Vibration Mode;
 Dynamic Response;
 Models;
 Structural Vibration;
 Turbine Pumps;
 Structural Mechanics