Resonance and stability analysis of a cracked gear system for railway locomotive.

• A dynamic model of cracked gear system of rail locomotive under stick-slip oscillation of the wheelset is established. • Parameter stability and sub-harmonic resonance are studied by multiple-scale method. • The influences of crack degree of teeth root on the stability are analyzed. • The stability boundary conditions of the frequency response are obtained. This paper aims to study parametric resonance and stability of a cracked gear system for railway locomotive, in which the modeling of gear backlash, static transmission error, time- varying meshing stiffness with crack, and stick-slip oscillation of the wheelset of rail locomotive is stressed. Considering the basic features and design parameters in the overall gear model, a single degree-of-freedom cracked gear model of railway locomotive is first established. Then, to obtain the frequency response and approximate solution of the proposed model, a multi-scale method is adopted. On this basis, parametric studies of resonance are conducted to reveal the effects of several key parameters, such as the slip rate, crack degree, damping ratio, static load and dynamic load. Meantime, stability of the cracked gear system is investigated analytically to obtain the boundaries that separate stable and unstable regions. Furthermore, the results of parametric resonance and stability analysis can offer useful references for researchers and engineers to achieve desirable design and control of dynamic behaviors of the gear transmission system for railway locomotive. [ABSTRACT FROM AUTHOR]