Out-of-plane free vibration of functionally graded circular curved beams in thermal environment

In this study, a modal superposition approach was adopted to derive the dynamic response of coupled vehicle and bridge systems. The train comprises a number of railway cars, each of which is modelled with ten degrees of freedom. The railway bridge was represented by a simply supported beam modelled as Euler-Bernoulli beam. In the numerical simulations, dynamic responses at the mid-span of the bridge and dynamic responses of the train under different train speeds are computed with random and non random rail irregularities. Effect of parameters like the depth and the position of the imperfection on the rail are taken into account. The coupled system of equations is integrated numerically by the newmark’s β method. The results obtained show that the rail irregularities affect the vertical acceleration of the train, which serves as a measure of the riding comfort of the trains moving over a bridge.

Dynamic analysis of train-bridge system and riding comfort of trains with rail irregularities

Wave motion analysis in arch structures via wavelet finite element method

Dynamic response of thick laminated annular sector plates subjected to moving load

Current investigation deals with the small and large amplitude free vibrations of a curved beam (arch) resting on a nonlinear elastic foundation. The arch is made of a functionally graded material, where the properties are graded across the thickness. Uniform temperature elevation in the arch is also considered and material properties are assumed to be temperature dependent. The governing motion equations of the arch are established using a higher order arch theory which satisfies the traction free boundary conditions and the von Karman type of non-linearity. The governing equations of the arch are solved for the case of an immovable pinned arch using the two step perturbation technique. Closed form expressions are given to estimate the nonlinear frequencies of the arch as a function of the mid-span deflection. Numerical results of this study are validated for the case of flat FGM beams on elastic foundation. Afterwards, novel numerical results are given to explore the influences of power law index, elastic foundation coefficients, length to thickness ratio, length to radius ratio, and the temperature effects.

Jong-Shyong Wu

Papers

Out-of-plane responses of a circular curved Timoshenko beam due to a moving load