Abstract: Torsional vibration responses of a nonlinear shafting system are
studied by a modified Riccati torsional transfer matrix combining with the
Newmark-β method. Firstly, the system is modeled as a chain consisting of
an elastic spring with concentrated mass points, from which a multi-segment
lumped mass model is established. Secondly, accumulated errors are eliminated
from the eigenfrequencies and responses of the system's torsional vibration by
this newly developed procedure. The incremental transfer matrix method,
combining the modified Riccati torsional transfer matrix with Newmark-β
method, is further applied to solve the dynamical equations for the torsional
vibration of the nonlinear shafting system. Lastly, the shafting system of a
turbine-generator is employed as an illustrating example, and simulation
analysis has been performed on the transient responses of the shaft's torsional
vibrations during typical power network disturbances, such as three-phase short
circuit, two-phase short circuit and asynchronous juxtaposition. The results
validate the present method and are instructive for the design of a
turbo-generator shaft.
