摘要：This paper studies the ageing effect of mechanical joints reflecting from the tyre/joint impacting noise by measuring the vehicle structure-borne noise change. Field data is collected applying two measurement methods suitable for newly installed and existing old expansion joints. The measurement methodology is improved by designing and applying a trailer for equipment installation. The main advantage of this method is not to disturb existing traffic by lane closure for measurement. Field measurements were conducted regularly for a study period up to 16 months after new joint replacement to monitor the variation of the structure-borne noise change inside a test vehicle while passing through mechanical joints. Empirical relationship is developed based on the field data of the roadside airborne noise change and the vehicle structure-borne noise change. The roadside tyre/joint noises could be converted using calibrated empirical formula. Key result findings include the following. (1) The vehicle structure-borne noise change is found smallest during the 3rd–6th months even lower than that measured when a new joint is installed. The structure-borne noise change then keeps increasing afterwards till the end of the study period. (2) Similar observations are found in all study cases incorporating various mechanical joint types and test vehicle types.
