Cem Öztürk, Mehmet Karaca, Ramadan Soncu, Recep Akyüz, Eren Kulalı

Measuring of Core Split Line Defect on Pillar Type Vented Brake Disc and Investigation of Crack Occurrence Potential on the Disc Caused by Its Geometric Deviation

In this study, a measuring method was defined to convert the level of defects on the pillar type ventedbrake disc to numeric data where the defects were formed due to missing material in the structure of thedisc. Subsequently, the geometric defects which are existing in the core on the droplets were examinedwith the defined method in only pillar type vented brake disc. Finally, some thermal performance tests(brake disc thermal fatigue test on bench in accordance with Society of Automotive Engineers BrakeRotor Thermal Cracking Procedure for Vehicles (SAE J2928) [1] and brake disc crack test on vehicle;special test procedure of an original equipment manufacturer, which is performed for inspectingstructural strength) and thermal fatigue test with thermal shock (test procedure formed by authors) wereperformed with defected brake discs to evaluate the risk of defected brake disc usage on the vehicle interms of safety. The main open point is to determine whether the defect can transform to crack byinfluencing with notch effect during the worst usage conditions. In the conducted tests; it wasinvestigated that the worst core split line defects which are specified by the defined measuring flow maycause a crack formation by proceeding notch effect under the worst usage condition. In order to simulatethe worst usage condition; test laboratories, equipment and test track were used in this period forperforming brake disc thermal fatigue test, crack test with thermal shock and crack test on vehicle.

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1. Brake Rotor Thermal Cracking Procedure for Vehicles Below 4 540 kg GVWR J2928_201207, https://www.sae.org/standards/content/j2928_201207
2. T.J. Mackin et.al., Thermal cracking in disc brakes, Engineering Failure Analysis 9, 2002, 63 – 76
3. D.M. Stefanescu. ASM handbook Vol.15 Casting, 2002, p 516- 523
4. D.M. Stefanescu, ASM handbook Vol.15 Casting, 2002, p 1189, p 1231
5. Amol, A., Ravi, R., FE Prediction of Thermal Performance and Stresses in a Disc Brake System, Journal of SAE, 2572 (2008), 1, pp. 5-8
6. C.W. Meyers and J.T. Berry, The Impact of Robotics on the Foundry Industry, Paper 30, Trans. AFS, 1979, p 107-112
7. J S Campbell, Principles of Manufacturing Materials And Processes, Tata McGraw Hill, 1995.
8. P C Pandey and C K Singh, Production Engineering Sciences, Standard Publishers Ltd., 2003.
9. S Kalpakjian and S R Schmid, Manufacturing Processes for Engineering Materials, Pearson education, 2009. 4. E. Paul Degarmo, J T Black, Ronald A Kohser, Materials and processes in manufacturing, John wiley and sons, 8th edition, 1999
10. Shaniavski, AA. Synergetical models of fatigue-surface appearance in metals: the scale levels of self-organization, the rotation effects, and density of fracture energy. In: Frantsikony PROBAMAT- 21st Century: Probabilities and Materials. Netherlands: Kluwer Academic Publisher; 1998, p.11-44.
11. Maillot V., Fissolo. A. Degallaix. G. and Degallaix S., Thermal fatigue crack networks parameters and stability: an experimental study, In. J. Solids and Structures, 42, 759-769 (2005)
12. Ivanova VS. Synergetics. Strength and failure of metallic materials. Russian, Moscow: Nauka; 1992.
13. B. Goo, and C. Lim, Thermal fatigue of cast iron brake disk materials, Journal of Mechanical Science and Technology 26 (6) (2012) 1719~1724
14. G. Gigan, V. Norman, J. Ahlström and T. Vernersson, Thermomechanical Fatigue of Grey Cast Iron Brake Discs for Heavy Vehicles, projects 2012-03662 and 2012-03625
15. Amol A. Apte and H. Ravi,FE Prediction of Thermal Performance and Stresses in a Disc Brake System, , journal of SAE ,2008.
16. Pevec M, et al. Elevated temperature low cycle fatigue of grey cast iron used for automotivebrake discs. Engineering Failure Analysis 2014; 42: 221-230
17. C. Maraveas, Y.C. Wang, T. Swailes, G. Sotiriadis, An experimental investigation of mechanical properties of structural cast iron at elevated temperatures and after cooling down, Fire Safety Journal 71 (2015) 340–352
18. Z.Ertekin, N. Özkurt, Noise Analysis of Air Disc Brake Systems Using Wavelet Synchrosqueezed Transform, Celal Bayar University Journal of Science Volume 15, Issue 4, 2019 p 409- 414.
19. Beloiu, DM, Ibrahim, RA. 2006. Analytical and experimental investigations of disc brake noise using the frequency‐time domain, Structural Control and Health Monitoring. The Official Journal of the International Association for Structural Control and Monitoring and of the European Association for the Control of Structures; 13(1): 277-300.
20. Contour Measuring System, Mitutoyo, CV3200, https://www.mitutoyo.co.jp/eng/support/service/catalog/03/E15010.pdf