Mechanical Modelling of Static Hysteresis in Under Ballast Mats Using a Novel Rheological Approach

Area of Science:

• Civil Engineering
• Mechanical Engineering
• Railway Engineering

Background:

• Under ballast mats (UBMs) are crucial components in ballasted track structures for mitigating railway-induced vibrations.
• These vibrations impact human well-being and the surrounding natural and built environments.
• A key characteristic of UBMs is energy dissipation, evident as hysteresis loops in load-deflection curves, even under static loading.

Purpose of the Study:

• To develop a novel mechanical model for under ballast mats (UBMs).
• The model aims to accurately replicate the energy dissipation phenomenon observed in UBMs under static loads.
• To provide a theoretical framework for understanding and optimizing UBM performance in vibration reduction.

Main Methods:

• Formulating constitutive equations for the UBM model as a nonlinear set of ordinary differential equations.
• Employing an optimization procedure to calibrate model parameters.
• Matching the integrated results of the theoretical model with experimental test data for UBMs under static conditions, adhering to EN 17282:2020-10.

Main Results:

• A validated nonlinear mechanical model capable of simulating UBM energy dissipation under static loads.
• Quantification of hysteresis loop behavior in UBMs during static loading.
• Demonstration of the model's accuracy through comparison with experimental results.

Conclusions:

• The proposed mechanical model effectively captures the static energy dissipation behavior of under ballast mats.
• This work provides a valuable tool for designing and implementing more effective railway vibration mitigation strategies.
• Understanding static hysteresis is essential for optimizing UBM performance in real-world railway applications.