A COMPARATIVE STUDY ON THE TORSIONAL VIBRATION ATTENUATION OF CLOSED-LOOP INTERNAL COMBUSTION ENGINE SHAFTING USING TUNED MASS DAMPER AND NONLINEAR ENERGY SINK

Traditional linear vibration absorber has long been used in vibration suppression, but its performance is limited by its narrow bandwidth. Considering that the cyclic excitation force of closed-loop shafting of internal combustion engine varies with the speed, it is necessary to achieve efficient vibration reduction in a relatively wide frequency domain. In order to investigate the feasibility of nonlinear energy sink (NES) replacing tuned mass damper (TMD) to suppress the torsional vibration of crankshaft, a multi-inertias nonlinear closed-loop self-excited coupled oscillation model (M-NCSCO) is established in this study. Based on this, the effects of TMD and NES on torsional vibration of crankshaft are studied. The transient and steady-state torsional oscillations at different coaxial segments of shafting are considered comprehensively in the analysis process. In addition, three functions of vibration density, performance lead efficiency and fluctuation ratio are defined to consider the performance of the dynamic vibration absorbers (DVA). The efficiency and robustness of NES and TMD under different design parameters (variable stiffness, variable damping and variable position arrangement) are discussed. The results show that NES and TMD have different stiffness and damping failure interval when controlling crankshaft torsional vibration. With the change of design parameters, NES and TMD lead the performance of vibration reduction alternately, with a combined performance of 24.5% for NES and 3.3% for TMD. At the same time, NES has a high damping dependence (13.6%), TMD has a high stiffness dependence (3.6%) and position dependence (25.6%).