William A. Fladung

Application of a generalized residual model to frequency domain modal parameter estimation

Residuals have long been used in frequency domain parameter estimation methods to model the influence of out-of-band modes but, typically, as a fixed set of no more than two or three terms. Recently, a systematic approach to the use of residual polynomials has led to the development of a generalized residual model. The use of a generalized residual model with rational fraction polynomial frequency domain parameter estimation methods allows the contribution of out-of-band modes to be included without increasing the model order and creating additional computational poles. Of particular interest is the use of the generalized residual for single-degree-of-freedom (s.d.o.f.) techniques, which generally do not consider the residual effects and suffer accordingly. With the use of generalized residuals, it becomes possible to properly account for nearby modes and also extract accurate residues with an s.d.o.f. algorithm. The development of the generalized residual polynomial model is outlined and a new s.d.o.f. frequency domain algorithm with generalized residuals is developed.

Integration of VXI data acquisition into matlab

This paper describes the integration of VXI data acquisition into MATLAB®, which has applications in education, research and industry. VXI is a non-proprietary standard for instrumentation quality data acquisition hardware and MATLAB is a high-level programming environment. MATLAB is linked to the VXI hardware through a plug&play library, and data is read directly into MATLAB for numerical computations. With the MATLAB/VXI interface, a multi-channel dynamic signal analyzer or application specific measurement software can be developed. The proof of concept is demonstrated with a multiple reference impact testing application.