Fraunhofer Institute for Mechanics of Materials IWMElastomeric coupling elements in noise barriers must withstand climatic and mechanical loads, sometimes extreme, for up to 50 years. Fraunhofer IWM is developing a scientifically sound methodology for service life prediction using time–temperature superposition, combined with innovative testing methods for in situ assessment of the current condition of ageing infrastructure. The project will deliver practical tools for material qualification that are relevant far beyond the railway sector to all industries using elastomeric sealing systems exposed to environmental influences, from façade construction to plant engineering.
Investigation of the long-term behaviour of elastomeric coupling elements in noise barriers under environmental exposure
Ongoing research project
Project description
Market needs and challenges
Elastomeric coupling elements (EPDM, CR, Sylomer) decouple components of noise barriers and are intended to remain functional for more than 50 years. They are exposed to combined climatic loads (UV radiation, moisture, temperature), pollutants (brake dust, ozone, NOx/SOx) and mechanical loads (self-weight, aerodynamic loading from passing trains). Existing regulations hardly account for these combined effects, resulting in a lack of reliable evidence of service life and leaving operators facing uncertain maintenance risks.
The project's approach
Based on a comprehensive analysis of regulations and the literature, Fraunhofer IWM is developing a model that prioritises the effects of ageing factors, together with a design of experiments test plan. Time–temperature superposition is used to generate master curves for key mechanical properties, enabling extrapolation to 50 years. In parallel, two non-destructive in situ testing methods (hardness measurement and ultrasound) are being tested and validated for practical use.
Contribution to addressing the challenges
The project will deliver a validated, practical methodology for demonstrating the fitness for use of elastomeric components, including a risk matrix, a decision flowchart and proposals for optimising inspection intervals. These elements will feed directly into a potential update of the EBA regulations and provide a robust, scientifically substantiated basis for safe and cost-effective operational decisions.
Fraunhofer IWM’s work packages
Fraunhofer IWM leads the project and develops: (1) a structured analysis of regulations and the state of scientific knowledge, including identified gaps; (2) an influence diagram and a risk matrix for prioritising ageing factors, along with a TTS test plan; (3) comprehensive experimental data and master curves for mechanical properties (hardness, strength, elasticity, damping) under thermal exposure, UV radiation, and static and cyclic loading; (4) validation of the model using field data, laboratory data and data from actual components; (5) specific elements for updating the EBA regulations, as well as an assessment of optimised inspection methods and intervals, including two tested in situ testing methods.
Client
