# 고속철도용 윤축의 정${\cdot}$동적파괴인성 평가

• Published : 2005.06.01

#### Abstract

The safety evaluations of railway wheelsets make use of the static fracture toughness obtained in ingot materials. The static fracture toughness of wheelset materials has been extensively studied by experiments, but the dynamic fracture toughness with respect to wheelset materials has not been studied enough yet. It is necessary to evaluate the characteristics of the fracture mechanics depending on each location for a full-scale wheelset for high-speed trains, because the load state for each location of the wheelset while running is different the contact load between the wheel and rail, cyclic stress in the wheel plate, etc. This paper deals with the fracture toughness depend on load rates. The fracture toughness depending on load rate data shows that once the downward curve from quasi-static values was reached, subsequent values showed a slow increase with respect to the impact velocity. This means that dynamic fracture toughness should be considered in the design code of the wheelset material.

#### References

1. BILD am Sonntag, 7 Juni, 1998
2. K Hirakawa, M Kubota, On the fatigue design method for high-speed railway axles, Proc Instn Mech Engrs, vol.215, pp.73-82, 2001 https://doi.org/10.1243/0954409011531413
3. 平川賢治,時政勝行,鐵道車輛用輪軸の强度評價,住友金屬,32-3, pp.349-358, 1980
4. H. Sakamoto, K. Toyama, K. Hirakawa,Fracture toughness of medium carbon steel for railroad wheel, Material science engineering, Vol.285, pp.288-292, 2000 https://doi.org/10.1016/S0921-5093(00)00648-1
5. A. Ekberg, Rolling contact fatigue of railway wheels -a parametric study, Wear, 211, pp.280-288, 1997 https://doi.org/10.1016/S0043-1648(97)00106-3
6. Anders Ekberg, Peter Sotkovski, Anisotropy and rolling contact fatigue of railway wheels, Journal of fatigue 23, pp.29-43, 2001 https://doi.org/10.1016/S0142-1123(00)00070-0
7. Makoto Akama, A study on the critical crack sizes that cause wheel fracture. World Congress Railway Research 2001.10
8. L. Ramanan, R.K.Kumar, Thermo-mechanical finite element analysis of a rail wheel, International journal of mechanical sciences, Vol.41, pp.487-505, 1999 https://doi.org/10.1016/S0020-7403(98)00078-2
9. ASTM E399, Standard test method for plane strain fracture toughness of metallic materials, 1997
10. ASTM E813, Standard test method for JIC, a measure of fracture toughness, 1989
11. ASTM E1820-99a: Standard test method for measurement of fracture toughness, 1999
12. ASTM E24.03.03. Proposed standard method of test for instrumented impact testing of precracked charpy-specimens of metallic materials