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Within the SILVARSTAR project, a user-friendly frequency-based hybrid prediction tool is developed to assess the environmental impact of railway induced vibration. This will be implemented in the existing noise mapping software IMMI. The vibration level in a building in each frequency band isexpressed as the product of source, propagation and receiver terms. A hybrid approach is used that combines experimental data with numerical predictions, providing increased flexibility and applicability. The train and track properties can be selected from a database or as numerical values. The user can select soil impedance and transfer functions from a database, pre-computed for a widerange of parameters with the MOTIV and TRAFFIC models. An experimental database of force densities, transfer functions, free field vibration and input parameters is also integrated into the new tool. The building response is estimated by means of empirical correction factors. Assumptions withinthe modelling approach can influence the prediction accuracy and the present paper aims to quantify these. We focus on the influence of train speed and soil properties on the compliance of the track-soil system and the free field response.

One of the main objectives of the SILVARSTAR project is to develop a user-friendly frequency-based hybrid prediction tool to assess the environmental impact of railway induced vibration. This model will be integrated in the existing noise mapping software IMMI. Following modern vibration standards and guidelines, the vibration level in a building in each frequency band is expressed as the sum (in decibels) of source, propagation and receiver terms. Each term can be determined experimentally or predicted with numerical models, resulting in a hybrid prediction model that provides increased flexibility and applicability. This paper focuses on the assessment of several modelling assumptions made in the prediction tool, as well as the validation of the computational core by comparing results with those obtained with state-of-the-art prediction models for several numerical case histories. Furthermore, measured transfer functions and train passages at a site in Lincent (Belgium) are used for experimental validation of the prediction tool, and to show its capability for hybrid predictions. ispartof: pages:1-15 ispartof: Proceedings of the 30th International Conference on Noise and Vibration Engineering, ISMA 2022 pages:1-15 ispartof: 30th International Conference on Noise and Vibration Engineering, ISMA 2022 location:Leuven, Belgium date:12 Sep - 14 Sep 2022 status: Published online

The main objective of the SILVARSTAR Shift2Rail project is to develop validated software tools for application in the field of ground vibration and auralisation in the railway sector. The first project work stream focuses on the prediction of ground vibration through the development and validation of a hybrid approach, combining numerical prediction with experimental results. The general framework adopted expresses the vibration level in a building as the product of terms describing the source, the propagation through the soil and the receiver. For each term, a database of both measured and pre-computed data is provided, allowing rapid calculations to be performed. In the upcoming project phase, this ground vibration software will be integrated in an industrial noise mapping software (IMMI). This will result in a unique software platform that will allow engineers to perform noise and vibration environmental impact studies within the same software environment, on a large scale. In the second work stream, auralisation and Virtual Reality (VR) software tools are developed based on physical models to synthesise railway noise in high quality. The novel auralisation and VR tools enable perception-based evaluation of noise mitigation technologies and an effective demonstration of different noise scenarios, including noise mitigation measures and vehicle design variants. This will support decision-making and facilitate communication with stakeholders through VR prior to project delivery. The new software tools will be made available to the industry at the end of 2022.

International audience; In this work a semi analytical finite element formulation using Non-Uniform Rational B-Splines (NURBS) basis function is presented for modeling the dispersed wave propagation in heterogeneous waveguides. Convergence studies are carried out by considering a 2D constant-thickness isotropic elastic plate. The results were compared with the ones obtained by analytical methods and by conventional SAFE method. For all of cases, the dispersion curves evaluated by using enriched-NURBS basis have a significant better precision than using conventional Lagrangian elements (for the same number of degrees of freedom).