Prototyping and Testing of Electrically Conductive Thermoplastic Polyurethane (TPU) Railroad Suspension Pad

University The University of Texas Rio Grande Valley (UTRGV)
Principal Investigators Robert Jones, Ph.D., Mechanical Engineering(PI)
Constantine Tarawneh, Ph.D., Mechanical Engineering ( Co-PI)
PI Contact Information Mechanical Engineering
EENGR 3.246
Dept. (956) 665-2394
Office (956) 665-5019
robert.jones@utrgv.edu
Funding Source(s) and Amounts Provided (by each agency or organization) Federal Funds (USDOT UTC Program): $63,251
Cost Share Funds (UTRGV): $20,868
Total Project Cost $84,119
Agency ID or Contract Number DTRT13-G-UTC59
Start and End Dates February 2017 – August 2018
Brief Description of Research Project   This research will take formulations of carbon nanofibers in thermoplastic polyurethanes (TPU), which have shown promising levels of electric conductivity, for use in a conductive steering pad, and prepare them for deployment in a commercially viable product. Plain elastomers are insulators and prevent transmission of current from rail to frame to signal door or gate opening devices. In addition, the thermal insulating properties of these materials reduce the rate of heat flow from bearings through the bearing adapter and into the side-frame, where it can be dissipated. Previous studies performed by the University Transportation Center for Railway Safety (UTCRS) revealed that traditional conductive additives, such as carbon black, must be applied at high volume fraction in order to generate sufficient conductivity, which in turn results in substantial increases in pad stiffness and degradation of pad durability. Vapor Grown Carbon Nanofibers (VGCNF) are extremely efficient conductive additives that can produce the desired conductivity at much lower concentrations and with less impact on mechanical performance than traditional additives. Prior efforts have identified a TPU carbon nanofiber combination and fiber loading that produces excellent conductivity, and results in an electrically conductive part when molded under commercially useful molding temperatures. The identified system first needs to be scaled from laboratory quantity testing to injection molding quantities, and then prototyped. Moreover, the microstructural contributions to conductivity as well as the allowable processing range need to be fully described in order to support process development and quality control processes in commercialization.
Keywords Railway safety, railroad bearing health monitoring, bearing condition monitoring, wireless sensors, low-power sensors, compact analysis module, bearing-level sensor module

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Report http://www.utrgv.edu/railwaysafety/_files/documents/research/mechanical/utcrs-utrgv-research-2017cy-prototyping-conductive-tpu-railroad-suspension-pad.pdf
Project Website http://www.utrgv.edu/railwaysafety/research/mechanical/2017/prototyping-conductive-tpu-railroad-suspension-pad/index.htm