Dramatic Effect of Cross-correlations in Random Vibrations of Discrete Systems, Beams, Plates, and Shells

Book excerpt: This volume explains the dramatic effect of cross-correlations in forming the structural response of aircraft in turbulent excitation, ships in rough seas, cars on irregular roads, and other dynamic regimes. It brings into sharp focus the dramatic effect of cross correlations often neglected due to the analytical difficulty of their evaluation. Veteran author Professor Isaac Elishakoff illustrates how neglect of cross correlations could result in underestimation of the response by tens or hundreds of percentages the effect of the random vibrations of structures' main elements, including beams, plates, and shells. Clarifies the common misconception that natural frequencies of structures are well apart from each other; Illustrates that the interaction of associated modes in plates can dramatically alter the random response due to presence of coinciding frequencies; Demonstrates that natural frequencies in beams on elastic foundation, as well as cylindrical or spherical shells, might cluster together resulting in substantial percentage error if cross-correlations are ignored.