Further Investigation of Disc Pad Compression during ISO Compressibility and Dynamic Modulus Measurements
2025-01-0334
To be published on 09/15/2025
- Event
- Content
- In an earlier publication, it was reported that the pad compressibility measured under 160 bars on Lowmet formulas keeps decreasing with increasing number of repeated measurements due to unrecoverable residual deformation of the friction material combined with increasing moisture adsorption, which increases the hardness of the friction material. This current investigation was undertaken to find out if this same phenomenon occurs for NAOs under a low pressure of 100 bars during the compressibility measurement and under 45 bars during the dynamic modulus measurement. In all cases, it is found that the same phenomenon occurs, meaning that friction materials become permanently compressed without full recovery, making them harder to compress and raising up the modulus. The dynamic modulus of friction material attached to a backplate is found to be underestimated by 3.5% as compared with the friction material without the backplate, using the iETEK estimation method.
- Citation
- Sriwiboon, M., Rhee, S., and Sukultanasorn, J., "Further Investigation of Disc Pad Compression during ISO Compressibility and Dynamic Modulus Measurements," SAE Technical Paper 2025-01-0334, 2025, .