Model Reduction of Large Elastic Systems A Comparison Study on the Elastic Piston Rod

摘要

Various model reduction techniques (Guyan, Dynamic, IRS, SEREP, CMS, Krylov) are applied to the elastic piston rod. Their results are verified comparing eigenfrequencies and eigenvectors, respectively, using modal correlation criteria [10]: Frequency Comparison, modified Modal Assurance Criterion, Normalized Modal Difference, Mass Normalized Vector Difference and Stiffness Normalized Vector Difference. A numeric approach is proposed for the iterative Preconditioned Conjugate Gradient (PCG) solution [12] of the linearized system Ax = b in case of A ill-conditioness. User intervention is discussed for all methods.