Experimental study on dynamic performance of typical nonballasted track systems using a full-scale test rig

This paper presents an experimental study on dynamic performance of China Railway Track System (CRTS) series track systems using a full-scale test rig. The test rig has been constructed based on 55.17m long full-scale nonballasted tracks composed of four typical CRTS track elements in high-speed railways. First, the dynamic characteristics of different nonballasted tracks are investigated by conducting wheel-drop tests, where a wheel-drop testing vehicle with a dropping wheelset is devised to provide the wheel-drop load. The vibration levels of different track systems are assessed by the root-mean-square acceleration per one-third octave band, and the vibration transmission characteristics of the CRTS series tracks are evaluated by transfer functions. Further, a mathematical track model is used to extract the dynamic stiffness and damping coefficient of the four types of nonballasted track systems based on the wheel-rail impact response. The vibration characteristics, the dynamic stiffness, and damping coefficient of different nonballasted track systems under various wheel-drop heights are compared and discussed in detail.