MODAL ANALYSES AND EXPERIMENTS FOR ENGINE CRANKSHAFTS

This study investigates the coupled modes, including coupled torsional -flexural vibration and coupled longitudinal-flexural vibration, for n on-rotating crankshafts which are free-free suspended. The finite elem ent models of those generally used are in two categories: beam element s and solid elements. By using these two models the natural frequencie s and mode shapes of two crankshafts are determined by the finite elem ent method (FEM) and compared with experimental data from modal testin g. The accuracy and validity of the analytical approaches are verified . The results show that the solid element is more appropriate than the beam element in the modal analysis of crankshafts. (C) 1998 Academic Press.