UTCRS Research, Testing, and Technology Capabilities

UTCRS supports collaborative research and applied testing programs spanning freight bearing performance, rail anchor mechanics, instrumentation, data systems, automation, and materials analysis.

UTCRS offers a rare combination of physical testing infrastructure, instrumented experimentation, public data stewardship, and in-house engineering development. For industry, agency, and research collaborators, that means one group can support the full path from hypothesis and hardware setup to data collection, analysis, and software delivery.

The UTCRS component library includes upwards of 150 cups and 100 cone assemblies, available with both steel and polymer roller cages. The defective inventory provides approximately 35 cups with documented spall sizes ranging from 0.06 in² to 10 in², 19 defective cones with spall sizes from 0.5 in² to 5.6 in², and 25 defective rollers with surface damage ranging from minor pitting to spalls covering up to 50% of the roller surface area.

All components are tracked through a serialized slot-based storage system. Records for each slot document cone assembly type, defect characteristics, prior experiment participation, and accumulated mileage. In addition to bearing components, the inventory system encompasses load sensors, accelerometers, thermocouples, load cells, and structural frame hardware.

Bearings are assembled from the serialized inventory to AAR recommendations. To press bearings onto specialized test axles, UTCRS operates the only 300-ton hydraulic press south of San Antonio. Loading measurements are recorded for each assembly to verify that test axles meet AAR recommendations for service-equivalent use.

All UTCRS instrumentation and measurement tools are calibrated annually. Certificates of calibration are maintained on-site and are available upon request.

The SBT is a dynamic bearing test rig designed to accurately replicate the operating conditions a freight bearing experiences during revenue service. The system applies vertical, lateral, and impact forces representative of real-world loading.

Recorded parameters include bearing vibration, temperature, applied forces, motor speeds, and motor power.

• Simulates train speeds up to 85 mph via a VFD-regulated 30 hp variable-speed motor coupled to a pulley system
• Supports loading up to 125% of AAR-recommended values
• Standard test loads for Class F and K bearings:
  • 17% (5,848 lbs), simulating an empty railcar
  • 100% (34,400 lbs), simulating a fully loaded railcar
• Accommodates AAR Class E, F, G, and K bearings on specialized test axles

UTCRS operates four Four-Bearing Testers (4BT), each accommodating four bearings on a shared axle for simultaneous testing and accelerated data collection under service-representative conditions. Recorded parameters include bearing vibration, temperature, vertical load, motor speed, and motor power.

• Simulates train speeds up to 85 mph via a VFD-regulated 30 hp variable-speed motor coupled to a pulley system
• Supports loading up to 125% of AAR-recommended values for Class F and K bearings
• One unit is permanently installed in an environmentally controlled chamber capable of maintaining ambient temperatures from −40°F to 150°F using industrial climate-control equipment and insulated enclosure panels
• Accommodates AAR Class E, F, G, and K bearings on specialized test axles
• Typical test campaigns are conducted to rated service life mileage or until bearing failure

In addition to the dynamic testers, UTCRS operates two static bearing adapter testers intended for load sensor validation, calibration, and cyclic loading evaluation. Both systems match the 125% AAR-recommended loading capability of the dynamic testers and support ramping and cyclic load profiles under varying bearing adapter temperatures.

The Material Test System (MTS) is used for longevity testing of load sensor designs. Because current designs incorporate screws and welds, it is critical to evaluate how long these components can withstand service conditions. The MTS applies cyclic loading between loaded and unloaded states over many cycles, allowing researchers to examine the damage sustained and make design changes if necessary.

Two hydraulic cylinders are used to apply cyclic loading to the adapter: a large cylinder with a 6-inch bore applies the load, and a smaller cylinder with a 1.5-inch bore interfaces with the machine to provide the cyclic action.

UTCRS has developed a modified Track Panel Pull Test (TPPT) to evaluate rail anchor performance under conditions representative of continuous welded rail (CWR) service. The apparatus applies controlled tensile forces simulating those experienced in field installations and measures the response using a high-precision load cell in conjunction with a linear variable displacement transducer (LVDT).

The TPPT produces force-displacement data that establishes a reproducible, quantitative basis for evaluating rail anchor performance and identifying force thresholds associated with anchor failure. This capability supports research into track structure integrity and provides a standardized method for comparing anchor designs and installation practices.

The UTCRS maintains an in-house engineering program combining hardware development, electronics design, and software engineering to advance instrumentation, automation, and data accessibility for railway safety applications.

Hardware and Electronics

Electrical engineering researchers design and fabricate custom electronic solutions for test and sensing applications, including automated load controllers, wireless sensing devices, and sensor interface circuits. Key systems developed and deployed at UTCRS include:

• Load controllers: maintain constant test loads by automatically compensating for fluctuations using closed-loop logic and integrated load sensors, ensuring service-equivalent loading throughout each test campaign
• PCBs for accelerometer mounting: small-footprint printed circuit boards designed to mount accelerometer sensors directly to bearing adapters for high-fidelity vibration capture
• Signal conditioning boards: filter boards that clean and condition raw accelerometer signals prior to recording, and amplifier circuits that ensure accurate, low-noise force measurements from load cells and strain gauges

Software and Data Infrastructure

Computer science researchers develop the public-facing data systems and analytical tools that extend UTCRS research to external partners. Current resources include:

• UTCRS Public Bearing Database (utcrsdatabase.utrgv.edu): hosts more than 10 TB of bearing vibration, temperature, and load data collected since 2013, freely accessible to the public
• Grease Oxidation Induction Time Prediction Model: web-based tool for estimating grease oxidation induction time from material and service parameters
• Bearing Operating Temperature and Vibration Calculator: interactive tool for estimating bearing thermal and vibration behavior under specified operating conditions

Future development plans include incorporating real-time test data ingestion and automated plotting capabilities into the public database, enabling industry and research partners to access experimental results rapidly without waiting for post-test processing.

All software tools and resources are available through the UTCRS official website under Technology Transfer → Products.

UTCRS provides material characterization services with a focus on lubricating greases and a broad range of solid materials. The following instruments support condition assessment, quality evaluation, and failure analysis.

Koehler Dropping Point Tester

The Koehler Dropping Point Tester measures the dropping point of lubricating grease in accordance with ASTM standards. The instrument heats grease specimens in a calibrated oil bath using precision test cups to determine the temperature at which the first drop of material falls, providing a quantitative measure of thermal stability and upper service temperature limit. Applications at UTCRS include evaluating fresh-versus-field grease samples to assess degradation, supporting performance and quality assessments, and informing failure analysis of bearing lubricants.

Thermogravimetric Analysis (TGA)

Thermogravimetric Analysis measures changes in a material's mass as a function of temperature or time under controlled thermal conditions. In lubricating grease analysis, sequential weight-loss events identify the decomposition of lighter lubricant fractions followed by the breakdown of heavier components and additives.

The TGA is applicable across a broad range of material classes:

• Polymers and plastics: filler content, thermal stability, decomposition profiles
• Composites and coatings: curing behavior, degradation, residual ash quantification
• Elastomers and rubbers: carbon black and additive quantification
• Metals and ceramics: oxidation resistance, corrosion studies, high-temperature stability
• Environmental and construction materials: organic/inorganic content, cement hydration, soil analysis
• Energy materials: coal, biofuels, battery components; combustion and stability evaluation

Differential Scanning Calorimetry (DSC)

Differential Scanning Calorimetry measures the heat flow into or out of a sample relative to a reference as both are subjected to a controlled temperature program. At UTCRS, the DSC is used to determine the Oxidation Induction Time (OIT) of lubricating greases, a quantitative measure of oxidative stability, and to estimate thermal decomposition energy as an indicator of residual lubricant content.

In addition to OIT and decomposition work, the DSC characterizes melting points, crystallization kinetics, and glass transition temperatures, supporting performance and stability evaluation across a wide variety of engineering and research materials.