Tire Testing Services
Flat Belt machines enable test data that truly depicts the tire shape and the tire contact patch; therefore, data from a flat belt offers a better foundation to build models off of. The better the model, the better the simulation. The better the simulation, the better decisions one can make about their product. That lack of capability and execution with other flat belt machines is what drove GCAPS to build the premier force and moment tire test facility (National Tire Research Center), which specializes in testing to complement activities performed by global tire and vehicle manufacturers. Using transformational technology, the NTRC extends the testing capability up to 200 mph, providing dynamic response and braking and torque capabilities – twice the capacity of other tire test machines.
Force & Moment
National Tire Research Center houses the world’s most capable Flat Trac ® Force and Moment Machine. Hydraulically controlled steering and camber inputs with a powerful, electric drive motor allows for precise control of the tire under combined load conditions. The machine was designed with test efficiency in mind to limit down time from tire, wheel, and belt changes.
- High speed capability:
- ±320 kph (200 mph)
- ±3000 rpm wheel speed
- Highest wheel torque capability available:
- ±10 kNm (7,375 lb-ft) @ 15 kNm/s (11,060 lb-ft/s)
- Uses fast response, precision electric motor
- High load testing:
- Fz Load: 30 kN (6,750 lb)
- Path following that mimics exact tire conditions from multiple maneuvers and tracks
- Improved control that results in a system with hardware-in-the-loop (HIL) capabilities
- High simultaneous tire positioning rates for transient event simulation
- Perform Drive File Replay of tire for model correlation and durability (track and highway)
- Enables direct component comparison to tire models
- Lap Durability
- Direct comparison of tire response from vehicle input for metric development and subjective correlation
- Impact testing for Ride and Load Model Parameterization
- Fast dynamic positioning:
- ±30 deg slip angle @ 90 deg/s
- ±10 deg inclination angle @ 38 deg/s
- 250 to 500 mm loaded radius @ 160 mm/s
Wet Tire Testing
The latest capability NTRC has recently introduced is laboratory indoor wet testing. NTRC is able to control and apply varying levels of water onto the flat surface of the force and moment machine. This has allowed NTRC to research methods for determining a tire’s hydroplaning characteristics. These characteristics include the speed at which a tire first has a reduction in lateral force, the coefficient of friction and many other variables. NTRC has developed a procedure for lateral characterization in wet conditions which has already shown promising results. These results have been shared at the Tire Technology Expo 2014 and the Intelligent Tire Conference 2013 through presentations and seminars. NTRC is also developing procedures to determine the traction characteristics of tires under several wet conditions. To successfully transfer the indoor wet characteristics for use in tire and vehicle development, comparisons to outdoor testing will be completed, analyzed, and understood.
Bring tire airborne and structure borne noise testing into the laboratory on a flat surface tire machine as an industry first. Multiple surfaces can be mounted on the LTRe belt to optimize for airborne, structure borne, or reference noise. Airborne noise is a result of deformation of the tire and treads. Structure borne noise is a result of a vehicle’s structure reacting to the forces transmitted through the tire, which are all precisely measured.
- Optimal airborne response between 625 and 2500 Hz
- Mimics AASHTO Designation: TP 76-13
- Use force and accelerometer data to find inputs to vehicle structure
NTRC is now expanding its testing capabilities to include outdoor surfaces and vehicle measurements. Working with a tire OEM, NTRC recently conducted measurements of seven different tire constructions on 14 different road surfaces, all in a span of two days. This outdoor testing was conducted on the Virginia Smart Road, a 2.2-mile, two-lane closed test track located in Blacksburg, Va., at the Virginia Tech Transportation Institute (VTTI). The test bed features 14 different roadway constructions that represent the majority of U.S. roadways. In-cabin noise measurements were taken across these surfaces at three different speeds and two directions of the road, with three samples collected from each speed and direction. The three samples were then averaged and reduced to include overall db(A) and a frequency analysis for each tire construction on each road surface, providing the tire OEM with an array of comparisons. Overall, these comparisons showed that different tread patterns were louder on certain roadway construction than others and that single surface measurements could be misleading to tire designers.
The operation at NTRC has expanded the testing capability for dry traction through the entire speed range of 320kph. This expanded capability has opened the door for new research and development into traction, thermal, and modeling. Examples of results from this work are the identification of speed input on longitudinal force response, including transient, as well as a new tire model utilizing the full dynamic capability of NTRC’s force and moment machine.
- Traction Testing Specification
- Globe’s most capable Laboratory Tire Traction Testing
- Increased wheel torque capability
- ±7375 lb ft (10,000 Nm) is 4-5 times larger than existing Flat-Trac systems
- Operable over full speed range
- Uses high response electric motor
- The most representative lab testing in existence via use of actual road conditions and a flat surface
- Uses track replay of the tire enabled by torque and dynamic positioning rates of the LTRe
- Can be taken to failure of the tire or to set conditions with the force generation monitored
- Can be performed on passenger-car, light-truck, or motorsport tires
- Important to forces, moments, and tire positions, producing more robust data required for tire modeling and data analyses
- Uses infrared sensors on the tire surface (tread and/or sidewall) and the belt material
- Thermal camera is available to enhance data, with analog outputs synced into the data acquisition system and two visual formats (video and multiple pictures)