Analysis of stick-slip, friction and sliding noises, material damping, abrasion and wear
The 2D Tribo-Acoustic test bench enables testing of a wide range of material pairings and components with real, highly dynamic relative motions and normal forces to analyze friction, friction noise, stick-slip, material damping and abrasion and wear. The precise reproduction of real dynamic load conditions provides more reliable predictions of the stick-slip risk occurring in practice and allows a more precise analysis of abrasion and wear. The completely friction-free design and extremely low operating noise of the actuators enable direct measurement of the frictional forces and accelerations occurring at the contact surfaces without influencing the test by additional leaf spring elements or friction in drive and guide elements. Stick-slip tests based on specified RANDOM excitation profiles (PSDs, e.g. in accordance with GMW 16321) and tests with constant relative speeds and normal forces (e.g. VDA-230-206, FORD CETP01.05) are possible as well. For tests in accordance with VDA 230-206, standardised sample holders with leaf springs are also available. As an option, tests can also be carried out with the addition of oils, lubricants, greases, various liquids or pastes as well as dirt and dust.
| x-axis | y-axis | |
| Max. displacement | 75mm pk-pk | 25mm pk-pk |
| Locking of individual axes | Yes, mechanical | Yes, mechanical |
| Adjustable overpressing / position | Yes, position controlled or locked | Yes, position controlled or locked |
| Max. velocity | 1m/s | 1m/s |
| Max. stat. preload force | 200N | 200N |
| Max. dyn. excitation force | 300N peak | 300N peak |
| Frequency range | DC-500Hz | DC-500Hz |
| Maximum payload | 2kg | 2kg |
| Types of excitation | User-defined ramp & sine signals, Definable Random PSD spectra Time History Replication | User-defined ramp & sine signals, Definable Random PSD spectra Time History Replication |
| Controlled variables | Position or acceleration, Force control available as an option | Position or acceleration, Force control available as an option |
| Overtravel protection | Yes | Yes |
| Overtemp protection | Yes | Yes |
| Operating Noise * | ||
Noise Rating Curve (NR) | NR18, typical | NR18, typical |
Sound Pressure Level ** | <25dB(A) | <25dB(A) |
Time Varying Loudness *** | <0,2 Sone | <0,2 Sone |
| Data acquisition | 8-simultaneously sampled inputs, 24-bit AD converter, sampling rates up to 256000 samples/second per channel |
|
| Measured quantities | Position, acceleration, force | Position, acceleration, force |
| Other measured variables | Temperature and humidity in the area of material samples | |
| Analyses Force/Acceleration/Position | Level over time, mean value, min and max value, rms N10, N50 and N90 percentile level |
|
| Acoustic analyses | Sound Pressure Level [dB(A)], level over time, mean value & max. value Time Varying Loudness, level over time, N10, N50 & N90 percentile level |
|
| Indicators friction | Coefficient of static friction, coefficient of sliding friction | |
| Indicators VDA 230-206 | max. acceleration, pulse count/pulse rate & Risk Priority Number (RPN) | |
| Indicators friction noise | FNI (Friction Noise Indicator), SSI (Stick-Slip Indicator) | |
| Data formats | TDMS-, WAV- and CSV-format. | |
| Dimensions (W*H*D) | approx. 680mm*319mm*747mm | |
| Weight | approx. 111kg | |
| Mains connection | 3 phases, 220-240VAC @50-60Hz, secured with 16A circuit breaker | |
| Compressed air supply | Filtered, oil-free compressed air, 6 bar@100 liters/min | |
* | Measured at 70cm from the shaker when excited with a typical Squeak & Rattle test profile in the frequency range from 5Hz to 100Hz with an averaged acceleration level of 0.3gRMS With simultaneous operation of both axes, the resulting noise level can increase by up to 6dB(A). |
|
** | A-weighted Sound Pressure Level, FAST (125ms), 100Hz to 20kHz | |
*** | N10 Percentile Level, loudness according to DIN45631/A1, measured in accordance with GMW14011 | |
- Highly dynamic simulation of relative motions, forces and accelerations in 2 axes
- Freely definable motion profiles
- Extremely quiet, frictionless actuators, no influence on the measurement data
- Recording of accelerations, forces, position, temperature and humidity
- Interchangeable sample holders with and without leaf spring
- Standard-compliant testing in accordance with VDA 230-206 including RPN calculation
- Measurement of static and dynamic friction
- Measurement & evaluation of friction noise
- Fully automatic execution of predefined test cycles
- Suitable for use in a climatic chamber in a temperature range from -40°C to +80°C
- Analysis and evaluation of the stick-slip risk of various material pairings and surfaces according to various test specifications
- Measurement of friction forces and friction coefficients
- Analysis of the emitted friction noise with acoustic and psychoacoustic analyses
- Aging, abrasion and wear tests
- Analysis of the damping properties
- Standardised leaf spring and specimen holder for tests in accordance with VDA 230-206
- Testing of friction, abrasion and wear of various material combinations with added oils, lubricants, greases, various liquids or pastes as well as dirt and dust
- Highly dynamic simulation of relative motions, forces and accelerations in 2 axes
- Freely definable motion profiles
- Extremely quiet, frictionless actuators, no influence on the measurement data
- Recording of accelerations, forces, position, temperature and humidity
- Interchangeable sample holders with and without leaf spring
- Standard-compliant testing in accordance with VDA 230-206 including RPN calculation
- Measurement of static and dynamic friction
- Measurement & evaluation of friction noise
- Fully automatic execution of predefined test cycles
- Suitable for use in a climatic chamber in a temperature range from -40°C to +80°C
- Analysis and evaluation of the stick-slip risk of various material pairings and surfaces according to various test specifications
- Measurement of friction forces and friction coefficients
- Analysis of the emitted friction noise with acoustic and psychoacoustic analyses
- Aging, abrasion and wear tests
- Analysis of the damping properties
- Standardised leaf spring and specimen holder for tests in accordance with VDA 230-206
- Testing of friction, abrasion and wear of various material combinations with added oils, lubricants, greases, various liquids or pastes as well as dirt and dust
Testing of stick-slip risk in accordance with VDA 230-206
Reproducible, highly dynamic simulation of real load scenarios
To analyse the stick-slip risk of various material pairings in accordance with VDA 230-206, an optional probe attachment with integrated leaf spring and standard-compliant sample holders in semi-circular and flat designs is available. The leaf spring and specimen holder are quickly and easily mounted to the y-axis linear guide using four screws. The parameters required by the standard, such as maximum acceleration gmax, pulse rate, coefficient of static friction, coefficient of dynamic friction and the optional risk priority number (RPN), are calculated and displayed in the measurement software.
The integrated closed-loop multi-axis vibration control system enables reproducible simulation of real accelerations, relative motions and forces. Recorded time signal data can be quickly and easily transferred to the TIME-HISTORY controller. The RANDOM excitation mode enables endurance tests based on definable power density spectra (PSDs) for testing abrasion and wear.
Frictionless motion & extremely low operating noise
Fully automatic execution of predefined test sequences
The two air bearing, friction-free guided axes of the quiet electrodynamic drives enable high-resolution, direct measurement of the friction and normal forces actually occurring at the contact surface of the two materials. Any influence on the dynamic behavior of the test specimens and distortion of the measured frictional forces by coupled leaf springs and superimposed frictional forces in the guides of the moving axes is therefore eliminated. The extremely low operating noise enables the analysis and objective metrological evaluation of the recorded friction noise and superimposed disturbing impulses caused by stick-slip using acoustic and psychoacoustic analyses.
The integrated automatic mode enables the definition and fully automated execution of predefined test cycles. The position of the axes, the excitation signals to be used, dwell times at a specified position as well as the test and measurement duration can be defined, executed fully automatically and saved in various test steps. If the test stand is integrated into a climate chamber, the climate chamber can also be controlled as an option.
