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. 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 |
| 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 (OPTION) | Sound Pressure Level [dB(A)], level over time, mean value & max. value Time Varying Loudness, level over time, N10, N50 & N90 percentile level |
|
| Key figures | FNI (Friction Noise Indicator), SSI (Stick-Slip Indicator) | |
| Data formats | All data is stored in TDMS-format, time signals from the accelerometers and the microphone can also be saved in WAV- and CSV-format. | |
| Dimensions (W*H*D) | approx. 680mm*302mm*735mm | |
| Weight | approx. 110kg | |
| 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 recorded 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
- No influence on stick-slip and force measurement unlike conventional leaf spring mechanisms
- Measurement of static and dynamic friction
- Measurement & evaluation of friction noise
- Recording and evaluation of stick-slip
- Precise measurement of static and sliding friction
- 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
- Measurement of friction forces and friction coefficients
- Recording and analysis of the emitted friction noise with acoustic and psychoacoustic analyses
- Aging, abrasion and wear tests
- Analysis of the damping properties of different materials
- 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 recorded 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
- No influence on stick-slip and force measurement unlike conventional leaf spring mechanisms
- Measurement of static and dynamic friction
- Measurement & evaluation of friction noise
- Recording and evaluation of stick-slip
- Precise measurement of static and sliding friction
- 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
- Measurement of friction forces and friction coefficients
- Recording and analysis of the emitted friction noise with acoustic and psychoacoustic analyses
- Aging, abrasion and wear tests
- Analysis of the damping properties of different materials
- 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
Frictionless motion & extremely low operating noise
Reproducible, highly dynamic simulation of real load scenarios
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 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.
Statistics & objective key figures for friction noise & stick-slip
Fully automatic execution of predefined test sequences
The evaluation software enables the calculation of statistical parameters for the measured force, acceleration, sound level and loudness curves. Friction Noise Indicator (FNI) and Stick-Slip Indicator (SSI) allow the differentiation and separate evaluation of friction and sliding noise as well as superimposed, impulsive noise caused by stick-slip. Level curves and signal statistics are saved with the raw data and are available for further analyses in external data analysis programs.
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.
