|NuRail Project ID||NURail2017-UIC-R16|
|Project Title||Coupled Multibody and Finite Element Analysis of Rail Substructure Behavior|
|University||University of Illinois at Chicago|
|Project Manager||Craig Foster|
|Principal Investigator||Craig Foster|
|PI Contact Information|
|Funding Source(s) and Amounts Provided (by each agency or organization)|
|Total Project Cost||$|
|Agency ID or Contract Number||DTRT13-G-UTC52 (Grant 2)|
|Brief Description of Research Project||Under this project we will improve the coupled multibody/finite element model developed in the previous NURail project. Furthermore, we will apply the model to examine bridge approaches as well as examine vibrations in buildings. The model improvements will include using a physical damping matrix to better represent the damping in different components of the system, notably the fasteners. We will also couple the approach to a three-invariant visco-plastic soil plasticity model. This soil model will allow us to capture permanent settlement of the rail ballast, subballast, and subgrade.|
Two applications of the current model will be investigated. First, we will apply the models to examine the track transitions, especially bridge approaches. Such transitions are well known to cause more wear and maintenance than typical track stretches. We will also examine the potential of using an approach slab to reduce stress in the subgrade as well as the contact forces between the rail and wheel.
The second application to be studied here is the effect of vibrations from passing trains on nearby buildings. The modal decomposition used in this approach is natural for examining vibrations. The magnitude of both the displacement and acceleration will be used to quantify the effects of the vibration on structures, and these quantities will be compared to building code values to assess occupant comfort or, in extreme cases, building damage.
|Describe Implementation of Research Outcomes (or why not implemented)||This research is under way and scheduled to be completed by September 2018. |
The implementation of the bridge approach model has been completed. Preliminary examination of the some solutions to the approaches has also been presented.
Analysis of vibrations is underway and some preliminary results are complete. Coupling to the nonlinear model is in progress.
|Impacts/Benefits of Implementation (actual, not anticipated)||This project helps improve rail efficiency and reliability. Understanding the bridge approach problems can help in the design of approaches requiring less maintenance and having less downtime. The analysis can also help in determining optimal maintenance times and procedures.|
The study of vibrations in buildings can determine whether a site that is otherwise economical as a building site can be constructed for sufficient occupant comfort. Although beyond the scope of this project, the methodology can also be applied to examining strategies for damping or otherwise reducing vibrations.
These models can also be applied to a variety of mechanical problems involving rail and substructure, including derailment, uneven ballast settlement, and the effects of fouling on ballast behavior. The applications relate to safety as well as the efficiency and economy of the rail network.
|Final Report||NURail2017-UIC-R16 Final Report.pdf |