In recent years, using of fast vehicle became so important to the people. So analysis and design of beams subjected to moving load has unique position in engineering field. Many researchers investigated beams with moving load but their attitude limited to displacement and straight beam. Study of moving load has showed it’s important role when researchers have proved that structures endure moving loads have higher stress and tension especially by specific velocities that cause vibrations’amplitude goes up. Having knowledge on behavior of structures subjected to moving loads can help a lot in reduction of vibrations’amplitude, stress and lead to safer structures. In this study, first, governing equations for free vibration of curve beam are derived and natural frequencies are calculated for special cases. Then beam is discretized by Euler Bernoulli beam element and displacement of the beam is calculated by numerical method. After that total energy of beam for various speed is calculated. By attention to the behavior of energy vs speed curve, critical speeds are specified and investigated. Then it is proved that in critical speeds, special mode shape is activated and stores energy during the moving load’s time. In this speed other mode shapes have low energy when load left the beam. Therefore beam begins to vibrate with special mode shape. Then effect of different parameters as inner damping and radius of curvature are applied to beam’s displacement and total stored energy. Vibration of curve beam in moving load’s time domain and after that, have been investigated for various speeds. At the end, equivalent continuous load is compared with point force load. Keywords: Vibration, critical speed, curve beam, moving load, energy, mode shape
