Vibrational Interaction Analysis of Non-uniform Cross-Section Beam under Moving Vehicles

One of the engineers concern in designing bridges and structures under moving load is the uniformity of stress distribution. On the other hand dynamic behavior of a vehicle on a flexible support is of great importance this paper the analysis of a variable cross subjected to a moving load such as simple quarter-car (SQC) planar model and a two-axle dynamic system with four degrees of freedom (۴DOF) are investigated. Finite element method with cubic Hermitian interpo-lation functions is used to model the structure based on Euler-Bernoulli beam and Wilson-Ө direct integration method is implemented to solve time dependent equations implicitly. Effects of cross-section area variation, moving inertia on the deflection, natural frequencies and longitudinal stresses of beam are investigated. Results indicates using a beam of parabolically varying thickness with constant mass can decrease maximum deflection and stresses along the beam while increasing natural frequencies of the beam. Effect of moving mass inertia at high velocity ofmoving vehicle is also investigated and findings indicate effect of inertia is significant at high velocity .

Keywords:

moving vehicle , non-uniform cross -section beam , longitudinal stress , finite element method