Optimization of torsional vibration damper of cranktrain system using a hybrid damping approach

The focus of this research is to develop the optimum design of torsional vibration damper using hybriddamping approach to decrease the torsional vibrations in the cranktrain system of internal combustionengines (ICE). For this purpose, a double mass rubber and viscous torsional vibration damper (DMRV-TVD) are combined. The optimization procedure is carried out using genetic algorithm (GA) to determinethe best hybrid damping performance on cranktrain system of a four stroke and four cylinder dieselengine. Accordingly, twelve degrees of freedom lumped mass mathematical model of the proposed crank-train system is created. The stiffness and damping coefficients of viscous and rubber materials used inDMRV-TVD model are verified by modal test and finite element natural frequency analysis. Then, theexcitation torque is calculated considering the inertia forces and gas force, and Fourier series expansionis performed to obtain the harmonics of driven torque as the input load on the relevant masses. The rel-ative angular deflection of the front end point of the crankshaft is determined. Additionally, in order todecrease the torsional vibrations of the crankshaft, DMRV-TVD model is optimized depending on the vis-cous material parameters by defining the boundary conditions and objective function of the genetic algo-rithm. The comparative results show that the developed hybrid design of optimized DMRV-TVD reducedthe torsional vibrations by 50.17% when compared to the non-optimized DMRV-TVD. This achievedreduction in the torsional vibrations is expected to increase the engine performance and its durabilityas well as providing a better driving comfort and fuel efficiency