Cover
Vol. 23 No. 2 (2023)

Published: December 31, 2023

Pages: 58-71

Original Article

Experimental Study of the Effect of Wire Electrical Discharge Machining on Crack tip Opening Displacement for Compact Tension Specimens of Low Carbon Steel

Sara A. Khudair 1 Atheed H. Taha 1 Ameen A. Nassar 1
1 Department of Mechanical Engineering, College of Engineering, University of Basrah, Basrah, Iraq
History
  • Received: December 15, 2022
  • Revised: January 23, 2023
  • Accepted: February 5, 2023
  • Available Online: December 30, 2023
DOI

https://doi.org/10.33971/bjes.23.2.8

Abstract

Fracture mechanics approach is important for all mechanical and civil projects that might involve cracks in metallic materials the purpose of this paper is to determine a crack tip opening displacement fracture toughness experimentally, also study the effect of thickness on CTOD fracture toughness of low carbon steel and study the effect of Wire Electrical Discharge Machine (WEDM) to have a pre-crack, instead of fatigue pre-crack by using a CT specimen of low carbon steel with a thickness of (8,10, and15 mm), a width of 30mm, crack length of 15mm, and pre-crack of 1.3mm for all samples, this dimension according to ASTM-E399-13, by pulling the specimen in a 100 KN universal testing machine at a slow speed rate of 0.5 mm/min, the load applied on the specimen is generally a tension load. The crack tip plastically deforms until a critical point P C at this moment a crack is initiated. The computer-controlled universal testing machine gives the value of the load and the displacement transducer gives a crack mouth opening displacement. Critical crack tip opening displacement CTOD is found with the plastic hinge model (PHM) method. The result showed the stress intensity factor K I increases with increased loading in the elastic region and t he thickness effect refers to the effect of the plastic zone at the crack tip on the stress intensity factor, In a thin specimen, a plastic zone is large at the fracture tip leads to a high-stress intensity factor at the fracture tip but in the thick specimen, on the other hand, has a small a plastic zone and a low-stress intensity factor around the crack tip. The fracture toughness is found to increase with an increase in the thickness of specimens.

Keywords

References

  1. Hassanein Kh, “Problems by Using Experimental and Crack Propagation in Plane Stress Extended Finite Element Method (XFEM).”, Ph.D Thesis, Mechanical Engineering Department, College of Engineering, University of Basrah, , 2015.
  2. S.S. Nama and R.M. Laftah, “Investigation of Stress Intensity Factor for Corrugated Plates with Different Profiles Using Extended Finite Element (XFEM),” Basrah Journal for Engineering Sciences, vol. 18, no. 1, pp. 1–9, 2018.
  3. WeeLiam Kh., “CRACK TIP OPENING DISPLACEMENT (CTOD) IN SINGLE EDGE NOTCHED BEND (SEN(B)),” Ph.D Thesis, Mechanical Engineering Department, College of Engineering, Brunel University of London, 2018.
  4. H. Zhang, H. Zhang, X. Zhao, Y. Wang, and N. Li, “Study of Thickness Effect on Fracture Toughness of High Grade Pipeline Steel,” MATEC Web of Conferences., vol. 67, pp. 4–11, 2016.
  5. V. V. Chaudhari, D. M. Kulkarni, and R. Prakash, “Study of influence of notch root radius on fracture behaviour of extra deep drawn steel sheets,” Fatigue & Fracture of Engineering Materials & Structures, vol. 32, no. 12, pp. 975–986, 2009.
  6. T. L. Panontin, A. Makino, and J. F. Williams, “Crack tip opening displacement estimation formulae for C(T) specimens,” Engineering Fracture Mechanics, vol. 67, no. 3, pp. 293–301, 2000.
  7. D. Kulkarni, R. Prakash ,and A. KUMAR, “Experimental and finite element analysis of fracture criterion in general yielding fracture mechanics,” sadhan, vol. 27, no. December, pp. 631–642, 2002.
  8. S. K. Kudari and K. G. Kodancha, “On the relationship between J-integral and CTOD for CT and SENB specimens,” Frat. ed Integrità Strutt., vol. 2, no. 6, pp. 3– 10, 2008.
  9. D. Kulkarni, V. Chaudhari, R. Prakash, and A. Kumar, “Effect of thickness on fracture criterion in general yielding fracture mechanics,” Int. J. Fract., vol. 151, no. 2, pp. 187–198, 2008.
  10. D. M. Madyira, “Effect of Wire EDM on microstructure and fracture toughness of 7075-T6511 aluminum alloy,” Proceedings of the World Congress on Engineering, vol. 2218, pp. 1038–1042, 2015.
  11. J. Avila, V. Lima, C. Ruchert, P. Mei, and A. Ramirez, “Guide for recommended practices to perform crack tip opening displacement tests in high strength low alloy steels,” Soldagem & Inspecao, vol. 21, no. 3, pp. 290– 302, 2016.
  12. R. Soltysiak, D. Boroński, and M. Kotyk, “Experimental verification of the crack opening displacement using finite element method for CT specimens made of Ti6Al4V titanium alloy,” AIP Conference Proceedings., vol. 1780, 2016.
  13. M. Heidarvand, N. Soltani, and F. Hajializadeh, “Experimental and numerical determination of critical stress intensity factor of aluminum curved thin sheets under tensile stress,” Journal of Mechanical Science and Technology, vol. 31, no. 5, pp. 2185–2195, 2017.
  14. M. J. Abdulsada, “Experimental and Numerical Study of Mechanical Properties and Fracture Mechanics Analysis of AISI1010 Low Carbon Steel Welded Joints,” M.Sc. Thesis, Mechanical Engineering Department, College of Engineering, University of Basrah, 2018.
  15. S. Ahamed, Roshan, and Shilpa, “EVOLUTION OF TENSILE AND FRACTURE TOUGHNESS PROPERTIES OF ALUMINUM-7075 ALLOY REINFORCED WITH ZIRCONIUM SILICATE (ZrSiO4) PARTICULATES Dr.,” International Research Journal of Engineering and Technology (IRJET), vol. 07, no. 08, pp. 1314–1320, 2019.
  16. A. A. Nassar and E. G. Fayyad, “Linear and Non-Linear Stress Analysis for the Prediction of Fracture Toughness for Brittle and Ductile Material using ASTM E399 and ASTM E1290 By ANSYS Program package.” Materials Science and Engineering, vol.579, 2019.
  17. D. M. Madyira and E. T. Akinlabi, “Effects of wire electrical discharge machining on fracture toughness of grade 5 titanium alloy,” Proceedings of the World Congress on Engineering, vol. 2, no. March, pp. 1393– 1398, 2014.
  18. A. E. Elwi and G. Y. Grondin, “Simulation of Crack Propagation in Steel Plate with Strain Softening Model,” no. 266, 2006.
  19. C. al Kilicgil, “DEVELOPMENT OF A NEW METHOD FOR MODE I FRACTURE TOUGHNESS TEST ON DISC TYPE ROCK SPECIMENS,” La Soc, vol. 3, no. September, pp. 5–65, 2006.
  20. American Standard, “ASTM - E1290 Standard Test Method for Crack-Tip Opening Displacement ( CTOD ) Fracture,” Astm, vol. 03, no. March, pp. 1–13, 2003.
  21. A. Shukla, Practical fracture mechanics in design, 2005.
  22. American Standard, “Standard Test Methods for Tension Testing of Metallic Materials” 2013.
  23. American Standard, “Standard Test Method for LinearElastic Plane-Strain Fracture Toughness K Ic ” 2013.