<p>The design and development of novel high-end journal bearings have brought new momentum and opportunities for stabilizing and damping rotor systems in rotating equipment. The purpose of this study is to develop a two-dimensional database method (2D DM) for the rapid and accurate calculation of nonlinear hydrodynamic forces in cylindrical journal bearings, and to apply this method to investigate the bifurcation and nonlinear dynamic behavior of novel elastic interlayer journal bearing (EIJB) systems. A grid matrix is created using the journal eccentricity ratio and phase angle as the two dimensions, with grid nodes storing the hydrodynamic forces based on the Reynolds equation, thus forming a 2D matrix database. A cubic spline interpolation method is employed to evaluate the hydrodynamic forces in the database. A 6-DOF dynamic model of the journal-bearing-housing system is established for the EIJB system under unbalanced excitation and nonlinear hydrodynamic forces. Nonlinear dynamic analysis of the EIJB system is performed using bifurcation diagrams, journal center orbits, Poincaré maps, and amplitude spectra, with rotational speed, elastic interlayer stiffness, and damping ratio as control parameters. The results show that the stiffness and damping of the elastic interlayer positively influence the dynamic behavior of the bearing system. A viscoelastic interlayer with a high damping ratio could significantly improve system stability. This study provides a theoretical basis for the optimized design of EIJBs to improve dynamic stability and reduce sub-synchronous vibrations.</p>