Figure 1. Methods for static spring constant measurement: (a) Standard method for resilient pad; (b) Modified method for specimens after compression aging.
Figure 2. Load-displacement curve of the specimen measured by standard method.
Figure 3. Load-displacement curves of the specimen after compression aging: (a) to (c) are 4th cycle curves measured by standard method; (d) to (f) are curves measured by modified method.
Figure 4. Increase rate of spring constant and compression set after compression aging for time and temperature: (a) at 70℃; (b) at 85℃; (c) at 100℃.
Figure 5. Variation of property for ln(h) at 70℃, 85℃ and 100℃.
Figure 6. Arrhenius plots for spring constant increases of 10%.
Table 1. Load Values for Static Spring Constant Measurement
Table 2. Static Spring Constants for Compression aging
Table 3. Relationship between Variation of Property and ln(h)
Table 4. Arrhenius Equations as a Function of Temperature and Useful Life Prediction at using Temperatures
참고문헌
- KRS TR 0014, "Rail Fastening System", Korean Railway Standards (2009).
- D. Y. Sung and K. H. Park, "Evaluation of the degradation trend of the polyurethane resilient pad in the rail fastening system by multi-stress accelerated degradation test", JKSR, 16, 466 (2013). https://doi.org/10.7782/JKSR.2013.16.6.466
- ISO 11346, "Rubber, vulcanized or thermoplastic - Estimation of life-time and maximum temperature of use", (2004).
- C. S. Woo and S. S. Choi, "Useful Lifetime Prediction of Rubber Components Using Accelerated Testing", IEEE Trans Reliab, 59 (2010).
- R. P. Brown, "Practical guide to the assessment of the useful life of rubber", RAPRA Technology Limited (2001).
- R. P. Brown, "Physical Testing of Rubber", 3rd, Chapman & Hall, 287 (1996).
- L. Mullins, "Softening of Rubber by Deformation", Rubber Chem. & Tech., 42, 339 (1969). https://doi.org/10.5254/1.3539210
- J. H. Lee, J. W. Bae, J. S. Kim, T. J. Hwang, Y. S. Choi, K. S. Baek, and N. J. Jo, "Effect of Cure System on the Life-time of Hydrogenated NBR O-ring using Intermittent Compression Stress Relaxation (CSR)", Elast. Compos., 46, 144 (2011).