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Highlights • A novel periodic nonlinear model with implicit solving method for the damaged slab track. • An efficient implicit dynamic integration scheme based on the Newmark-β method and the Newton-Raphson method. • An efficient updating method for generalized internal force and tangent stiffness matrix in pseudo-spectral method. Abstract In order to evaluate the vibration response of the slab track with damage more efficiently in high speed railway, a periodic nonlinear dynamic model with implicit solving method for damaged slab track is proposed involving the damage constitutive relationship of concrete under uniaxial tension. The vibration equations of the nonlinear model are discretized via the periodic spectral method in space domain, and subsequently based on the Newmark- β method and the Newton-Raphson method, the implicit dynamic integration scheme is constructed in time domain. The detailed solving procedure of the implicit dynamic integration scheme with Newton-Raphson iteration for the periodic nonlinear model is illustrated ultimately. By comparing the implicit and explicit solutions of the periodic model, the correctness and efficiency of the periodic model are verified. Furthermore, the vibration response and the evolutional rules of structural damage for the slab track of high speed railway with different strength grades for concrete slab are investigated respectively via employing the periodic model with implicit solving method. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Slab tracks are common track structures in high-speed railways. In this study, a vehicle/slab track interaction model is developed based on vehicle–track coupling dynamics theory, and composite track elements are used to rapidly model the finite element equations of the slab track based on the stationary value theory of total potential energy. In the model, the rail is represented as a discretely-supported infinite beam, the slab and the base are considered as continuously-supported free beams, and the connections of the track structure are modelled as viscoelastic spring–damping elements. The composite track element method effectively derives the equations of motion with high or low degrees of freedom by increasing or decreasing the number of track elements; therefore, it can be applied to the dynamic analysis of the track and to investigate the dynamic responses of the slab track system, including the rail, pad, slab, Cement asphalt mortar (CA mortar) and base. The equations of motion of the vehicle system are also proposed using the finite element method. The vehicle system and the slab track system interact through the vertical wheel/rail force, which is approximated using Hertz contact theory. The dynamic responses of a slab track subjected to moving vehicle loads are analysed using dynamic simulations and are compared with another classic simulation method. The effects of random track irregularity and vehicle velocity on the dynamic responses of the slab track system are discussed. [ABSTRACT FROM AUTHOR]

The slab track of high speed railway has higher environmental noise emissions caused by a train running than the ballasted track. In order to predict and control wheel/rail rolling noise radiation due to roughness of wheel and rail running surface on slab track, a model is developed to calculate wheel/rail rolling noise of the slab track and analyze the influences of railway slab structure parameters on wheel/rail rolling noise. The results show that the rail noise occurs mainly in the middle and high frequency ranges of 500–2000Hz. The wheel noise is chiefly in the high frequency ranges of 1600–4000Hz, and the track slab noise radiates in the frequency ranges of 125–500Hz. Instantaneous noise pressure of the rail is first, the slab is second, the wheel is in between. The weights of the slab have more influence on emissions of the slab, but have little impact on noise emission of the wheel and rail. Below 500Hz, the greater weight of the slab is, the greater noise emission of the slab is, but above 500Hz, the result is the opposite. The CA mortar elastic modulus under the slab has little impact on noise emission of the wheel and rail, whereas has more influence on noise emissions of the slab. The greater elastic modulus of CA mortar under the slab is, the less noise emission of the slab is. The rubber pads installed under the slab have more influence on noise emissions of the slab than that of wheel and rail. All in all, the rubber pad under the slab is beneficial to wheel-rail noise reduction. [ABSTRACT FROM AUTHOR]