Influence of reduction and interpolation methods on the correlation of calculated and measured modal data of a solar array

Abstract

At Fokker Space and Systems the measured and calculated modal data of an ARA 3-panel-clean-wing were correlated. The number of degrees of freedom (dof's) of the finite element model (FEM) is about 6400 and of the measurement 32. Three methods were used to obtain corresponding dof's namely: 1) the number of dof's of the FEM was reduced with a static (Guyan) reduction method, 2) the number of dof's of the FEM was reduced with a dynamic reduction method, 3) the measured modeshapes were interpolated. The dynamic modal characteristics of the ARA 3-panel-clean-wlng were measured in three Independent modal tests, namely by Estec, University of Kassel, and Fokker Space and Systems. The correlation was investigated between: the reduced analytical modeshapes and the measured modeshapes, the full analytical modeshapes and the Interpolated measured modeshapes, and the static and dynamic reduced analytical modeshapes. Also the measured modal datasets were correlated with each other, hence test versus test. The results of the different correlations will be compared and conclusions will be presented.