Finite Element Method Approach Against to Brake Fading Problem in Railway Vehicle Brake Friction Element Design

Öz

Temperature increase occurs on the disc and pad surface due to long-term braking. With increasing temperature, an important problem called fading arises, which reduces brake performance. Friction element designers generally use experimental test methods such as dynamometers in the design stages in order to predict the fading problem. Although such experimental methods are accepted and reliable methods, they are disadvantageous in terms of time and cost. This study aims to provide thermal prediction by using computer-aided finite element methods instead of experimental methods against the fading problem in brake friction element designs and thus saving time and cost. For this purpose, thermal analysis was performed by modeling with the finite element method instead of traditional test methods, and these analysis results were confirmed by real railway tests. In real railway tests, the maximum temperatures occurring in the disc were measured with the help of a K-type thermocouple, and the results obtained were compared with the results of the analysis. As a result of the comparison, it has been observed that the values obtained as a result of the finite element method largely overlap with the values obtained as a result of the real railway tests. As a result of braking at 140 km/h, which is the maximum speed of the vehicle, the experimentally measured maximum average temperature is 384 °C, while the maximum temperature measured as a result of the simulation is 400 °C. The obtained data has revealed that the FEA can be used in brake friction element design to detect the attenuation problem, thus saving time and cost.

Anahtar Kelimeler

• Fading
• Disc Pad
• Thermal FEA

Demiryolu Aracı Disk Balatalarının Tasarımında Yüksek Sıcaklığın Neden Olduğu Fren Zayıflama Probleminin Belirlenmesi İçin Sonlu Elemanlar Yöntemi Yaklaşımı

Öz

Demiryolu aracı fren sürtünme elemanlarında, uzun süre fren yapılmasına bağlı olarak disk ve balata yüzeyinde sıcaklık artışı meydana gelmektedir. Artan sıcaklıkla birlikte fren performansını düşüren ve zayıflama (fading) olarak adlandırılan önemli bir problem ortaya çıkmaktadır. Sürtünme elamanı tasarımcıları, zayıflama problemini öngörebilmek amacıyla tasarım aşamalarında genelde dinamometre gibi deneysel test yöntemleri kullanmaktadırlar. Bu tarz deneysel yöntemler kabul görmüş güvenilir yöntemler olsa da zaman ve maliyet açısından dezavantajlıdır. Bu çalışma, fren sürtünme elemanı tasarımlarında zayıflama problemine karşı deneysel yöntemler yerine bilgisayar destekli sonlu elemanlar yöntemlerini kullanarak termal öngörüde bulunulmasını sağlamayı ve böylece zamandan ve maliyetten tasarruf elde edilmesini amaçlamaktadır. Bu amaçla geleneksel deney yöntemleri yerine sonlu elemanlar yöntemi ile modelleme yapılarak termal analiz yapılmış ve bu analiz sonuçları gerçek demiryolu testleri ile doğrulanmıştır. Gerçek demiryolu testlerinde diskte oluşan maksimum sıcaklıklar K tipi bir termokupl yardımıyla ölçülmüş ve elde edilen sonuçlar analiz sonuçları ile karşılaştırılmıştır. Karşılaştırma sonucunda sonlu elemanlar yöntemi sonucunda elde edilen değerlerin gerçek demiryolu testleri sonucunda elde edilen değerler ile büyük oranda örtüştüğü gözlemlenmiştir. Aracın maksimum hızı olan 140 km/h hızda yapılan frenleme sonucunda deneysel olarak ölçülen maksimum ortalama sıcaklık 384 °C iken simülasyon sonucunda ölçülen maksimum sıcaklık 400 °C’dir. Elde edilen veriler zayıflama problemini tespit etmek için sonlu elemanlar yönteminin fren sürtünme elemanı tasarımında kullanılabileceğini ve böylece zamandan ve maliyetten tasarruf sağlanabileceğini göstermektedir.

Anahtar Kelimeler

• Fren Zayıflaması
• Disk Balata
• Termal FEA

Kaynakça

1. [1] L. Abebe, R. Nallamothu, K. Subrahmanyam, S. Nallanothu, A. Nallamothu, “Thermal Analysis of Disc Brake Made of Different Materials,” SSRG International Journal of Mechanical Engineering, vol. 3(6), pp. 5-9, 2016.
2. [2] P. Milenkovic, S. Jovanovic, A. Jankovic, M. Milovanovic, N. Vitosevic, M. Djordjevic, M. Raiceviv, “The Influence of Brake Pads Thermal Conductivity on Passnager Car Brake System Efficiency,” Thermal Science, vol. 14, pp. 221-230, 2010, doi: 10.2298/TSCI100505016M
3. [3] F. Talati, S. Jalalifar, “Analysis of heat conduction in a disc brake system,” Heat Mass Transfer, vol. 45, pp. 1047-1059, 2009, doi: 10.1007/s00231-009-0476-y
4. [4] T. Piatkowski, H. Polakowski, M. Kastek, P. Baranowski, K. Damaziak, J. Malachowski, L. Mazurkiewicz, “Thermal measurement of brake pad linning surfaces during the braking process,” The international societyc for optical engineering, 2012, doi: 10.1117/12.918391
5. [5] A. Sinha, G. Ischia, C. Menapace, S. Gialanella, “Experimental characterization protocols for wear-products for wear products from disc brake materials,” Atmosphere, vol. 11, 2020, doi: doi:10.3390/atmos11101102
6. [6] M. Kchaou, A. Sellami, J. Fajoui, R. Kus, R. Elleuch, F. Jacquemin, “Tribological performance characterization of brake friction materials: What test? What coefficient of friction?,” Journal of Engineering Tribology, vol. 233, pp. 214-225, 2019, doi: 10.1177/1350650118764167
7. [7] P. Blau, “Compositions, functions, and testing of friction brake materials and their additives,” OAK ridge national laboratory, 2001.
8. [8] N. Stoica, A. Petrescu, A. Tudor, A. Predescu, “Tribological properties of the disc brake friction couple materials in the range of small and very small speeds,” 13th International Conference on Tribology, 2017, doi:10.1088/1757-899X/174/1/012019

9. [9] T. Singh, A. Patnaik, “Friction braking performance of nanofilled hybrid fiber reinforced phenolic composites: Influence of nanoclay and carbon nanotubes,” World Scientific, vol. 8, no. 3, 2013, doi:10.1142/S1793292013500525
10. [10] M. Kim, J. Kim, B. Goo, “Comparative studies of the tread brake dynamometer between dry and wet conditions,” Selected topics in system science and simulation in engineering, pp. 479-483, 2010.
11. [11] A. Vdovin, G. Gael, “Aerodynamic and thermal modelling of disc brakes challenges and limitations,” Energies, vol. 13 (1), pp. 1-12, 2020, doi: 10.3390/en13010203
12. [12] S. Zhang, Q. Hao, Y. Liu, L. Jin, “Simulation study on friction and wear law of brake pad in high-power disc brake,” Mathematical Problems in Engineering, vol. 2019, pp. 1-15, 2019, doi: 10.1155/2019/6250694
13. [13] G. Riva, “A methodology to simulate automotive disc brake tribology and emissions,” Doctoral Thesis in Machine Design KTH Royal Institute of Technology Stockholm, Sweden, 2020
14. [14] H. Cho, C. D. Cho, “A study of thermal and mechanical behavior for the optimal design of automotive disc brakes,” Automobile Engineering, vol. 222, pp. 894-915, 2008.
15. [15] K. Narayana, G. U. Rao, D. Simhachalam, B. Nagarju, “Finite Element Analysis of Solid and Ventilated Disc Brake,” International Journal of Science and Research (IJSR), vol. 3, no. 9, pp. 875-882, 2014.
16. [16] D. Nirmala, C. Kiran, “Otimized Design and Static, Dynamic Analysis of Disc Brake Using Finite Element Analysis,” International Journal of Engineering Research&Technology (IJERT), vol. 5, pp. 416-419, 2016.
17. [17] A. Belhocine, “Finite element analysis of automotive disk brake and pad in frictional model contact,” International journal of manufacturing, materials, and mechanical engineering (IJMMME), vol. 5, pp. 32-62, 2015, doi: 10.4018/ıjmmme.2015100103
18. [18] S. Gautam, S. Yadav, S. Akhtar, V. Shani, S. Tiwari, D. Yadav, S. Lal, “Finite Element Analysis of Disc Brake Using Ansys Workbench Software,” International Journal of Scientific & Engineering Research, vol. 6, pp. 1954-1959, 2015
19. [19] N. Liu, Z. Zheng, Y. Wu, X. Kong, H. Ding, “Finite Element Analysis of Drum Brake Assembly,” The Italian Association of Chemical Engineering, vol. 46, pp. 1057-1062, 2015, doi: 10.3303/CET1546177
20. [20] B. Goo, “A study on the contact pressure and thermo-elastic behavior of a brake disc pad by infrared images and finite element analysis,” Applied Sciences, vol. 8, no. 9, 2018, doi: 10.3390/app8091639
21. [21] S. Zhang, Q. Hao, Y. Liu, L. Jin, F. Ma, Z. Sha, D. Yang, “Simulation Study on Friction and Wear Law of Brake Pad in High-Power Disc Brake,” Mathematical Problems in Engineering, 2019, doi: 10.1155/2019/6250694
22. [22] G. Riva, F. Varriale, J. Wahlström, “A finite element analysis (FEA) approach to simulate the coefficient of friction of a brake system starting from material friction characterization”, Friction, vol. 9, 2020, doi: 10.1007/s40544-020-0397-9
23. [23] S. Gurumoorthy, S. Grandhi, S. Sridhar, “Brake pad wear prediction using finite element techniques,” SAE International, 2021, doi: 10.4271/2021-01-0810
24. [24] A. Rashid, N. Strömberg, “Thermomechanical simulation of wear and hot bands in a disc brake by adopting an eulerian approach,” Materials Science, pp. 1-10, 2013.