An explicit periodic nonlinear model for evaluating dynamic response of damaged slab track involving material nonlinearity of damage in high speed railway

For evaluating the vibration response of the damaged slab track efficiently, a novel explicit periodic nonlinear model for the damaged slab track in high speed railway involving material nonlinearity of damage is presented based on the theory of continuum damage mechanics and the constitutive relationship of concrete under uniaxial tension, where the infinite periodically supported composite beam for the track on the elastic foundation is truncated into a beam section with the length of a single vehicle by introducing periodic boundary conditions. The vibration equations of the nonlinear model are discretized into ordinary differential equations (ODEs) in space domain by the periodic spectral method, and then by applying the explicit central difference method these ODEs are solved with time-domain difference ultimately. The validity of the model is verified by the comparison of the results from the periodic model, finite element method (FEM) and the field test, and the reasonable values of the key computational parameters are recommended. Moreover, the influence of track structural parameters on the vibration response and damage evolution of CRTS II slab track of China's high speed railway is investigated with the periodic nonlinear model. And some practical conclusions for design and construction are acquired.