110 likes | 964 Views
Mechanical Vibrations Lecture 13. Multi-Degree of Freedom Force Vibration The Eigen -Value Problem Modal Analysis Solution. Mass Normalisation of Mode Shapes. Properties in Eigen Vector Matrices. Modal Analysis. Scale the mode shapes so that
E N D
Mechanical VibrationsLecture 13 Multi-Degree of Freedom Force Vibration The Eigen-Value Problem Modal Analysis Solution
Modal Analysis • Scale the mode shapes so that • Where is a matrix of the mass normalised mode shapes • This gives
Inverting the spatial matrix No Matrix Inversion
Summary of Process • Find mass and stiffness matrix • Find roots of characteristic equation • Find mode shapes • Mass normalise mode shapes • Use summing solution to find inverse of system matrix