Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Fatigue Life Estimation of Induction-Hardened Drive Shaft Under Twisting Loads

비틀림 하중을 받는 고주파열처리 드라이브 차축의 피로수명 평가

  • Received : 2017.01.09
  • Accepted : 2017.02.14
  • Published : 2017.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

The drive shaft of passenger vehicle has an important role in transmitting the torque between the power train system and the wheels. Torsional fatigue failures occur generally in the connection parts of the spline edge of the drive shaft, when there is significant fatigue damage under repeated twisting loads. A heat treatment, an induction hardening process, has been adopted to increase the torsional strength as well as the fatigue life of the drive shaft. However, it is still unclear how the extension of the induction hardening process in a used material relates to its shear-strain fatigue life range. In this study, a shear-strain controlled torsional-fatigue test with a specially designed specimen was conducted by an electro-dynamic torsional fatigue test machine. A finite element analysis of the drive shaft was carried out using the results obtained by the fatigue experiment. The estimated fatigue life was verified through a twisting load test of the real drive shaft in a test rig.

자동차 부품 중 드라이브 샤프트는 엔진에서 발생하는 토크를 바퀴에 전달하는 동력 전달장치의 핵심 부품이다. 엔진에서 입력되는 비틀림 하중과 주행 중 발생하는 실동하중에 의한 부품의 파손을 방지하기 위해, 고주파 열처리로 강도 및 피로수명이 개선되고 있다. 본 연구에서는 고주파 열처리에 따른 드라이브 샤프트의 피로수명을 정량적으로 평가할 수 있는 피로수명 평가기법을 구축하였다. 드라이브 샤프트의 소재인 SAE10B38M2 강재로 모재 및 경화깊이가 서로 다른 고주파 열처리 시편 두 종을 제작하여 비틀림 하중 하에서의 전단 변형률 제어 피로시험을 진행하였고, 변형률-수명 피로수명 평가에 필요한 피로 물성값을 구하였다. 얻어진 피로 물성값을 이용하여 드라이브 샤프트의 변형률 기반 피로해석을 진행하였으며, 얻어진 피로수명 결과를 시제품 피로시험 결과와 비교하여 해석기법의 타당성을 검증하였다.

Keywords

References

  1. Kang, D. H., Lee, B. J., Yun, C. B. and Kim, K. W., 2010, "Study on Torsional Strength of Induction-Hardened Axle Shaft," Trans. Korean Soc. Mech. Eng. A, Vol. 34, No. 5, pp. 645-649. https://doi.org/10.3795/KSME-A.2010.34.5.645
  2. Ko, J. B., Kim, W. K. and Won, J. H., 2005, "The effect on Fatigue Strength of Induction Hardened Carbon Steel," Journal of the Korean Society of Manufacturing Technology Engineers, Vol. 14, No. 6, pp. 83-87.
  3. Kim, W. K., Ko, J. B. and Kim, H. B., 2009, "A study on the Design on the Tubular Drive Shaft," Journal of The Korean Society of Manufacturing Process Engineers, Vol. 8, No. 3, pp. 7-12.
  4. Guk, D. S., Ahn, D. G., Lee, H. J. and Jung, J. H., 2015, "Investigation of Structural Safety of Monobloc Tubular Drive Shaft Subjected to Torque," Journal of the Korean Society for Precision Engineering, Vol. 32, No. 12, pp. 1073- 1080. https://doi.org/10.7736/KSPE.2015.32.12.1073
  5. Hur, M. D., Shim, T. Y., Lee, K. O. and Kang, S. S., 2008, "Fatigue Life Evaluation of the Power Train Part with Teat Treatment," Korean Society Of Precision Engineering Conference Proceedings, pp. 59-60.
  6. ANSYS Inc., 2016, ANSYS nCode DesignLife Release 11, http://www.ansys.com/products/Structures/ANSYS-nCode-DesignLife/.
  7. Basquin, O. H., 1910, "The Exponential Law of Endurance Tests," ASTM Proceedings, Vol. 10, pp. 625-630.
  8. Manson, S. S., 1953, "Behavior of Materials under Conditions of Thermal Stress," National Advisory Committee for Aeronautics.
  9. Coffin, L. F. Jr., 1954, "A Study of the Effects of Cyclic Thermal Stresses on a Ductile Metal," Transactions of the ASME, Vol. 76, pp. 931-950.
  10. ASTM E606/E606M, "Standard Test Method for Strain-Controlled Fatigue Testing," Annual Book of ASTM Standards, Vol. 03.01.
  11. Smith, K. N., Watson, T. and Topper, T. H., 1970, "A Stress-Strain Function for the Fatigue of Metals," Journal of Materials, Vol. 5, No. 4, pp. 767-778.
  12. Lee, Y. L., Pan, J., Hathaway, R. B. and Barke y, M. E., 2005, Fatigue Testing and Analysis: The ory and Practice, Butterworth-Heinemann, Oxford, pp. 136-139.
  13. Festigkeit, Wellen, Verbindungen, Federn, and Kupplungen, 2015, Maschinenelemente 1, Pearson, Deutschland, p. 286.