Torsional vibration responses of the engine crankshaft-gearbox coupled system with misfire and breathing slant crack based on instantaneous angular speed

Torsional vibration responses of an engine crankshaft-gearbox coupled system with misfire and breathing slant crack are investigated in this paper. The crankshaft is modelled by lumped mass method its dynamic equations deduced based on Lagrange equation. Both the time varying mesh stiffness gearbox composing a pinion gear response-dependent shaft element evaluated. Natural frequencies healthy cracked systems analysed respectively. vibrations instantaneous angular speed (IAS) flywheel driven compared among operating conditions normal, shaft. Simulation results validated experiments, which show that encoder better because it can monitor IAS simultaneously signals more prominent here.