مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

اثر تغییر جنس سرسیلندر از آلیاژ آلومینیم به منیزیم بر عمر خستگی کم‌چرخه آن

نوع مقاله : پژوهشی اصیل

نویسنده
حجت عاشوری
دانشگاه آزاد اسلامی واحد ورامین
10.48311/mme.25.2.77
چکیده
سرسیلندر یکی از قطعات مهم و چالش­برانگیز موتور است که خستگی ناشی از تنش­های ترمومکانیکی نقش موثری در ایجاد آسیب و کاهش عمر خستگی آن دارد. هدف این پژوهش ارزیابی عمر خستگی کم­چرخه سرسیلندر با تغییر جنس آن از آلیاژ آلومینیم A356 به آلیاژ منیزیم AZ91 است. در این پژوهش، تحلیل عمر خستگی کم­چرخه سرسیلندر با استفاده از روش اجزای محدود و نرم­افزار انسیس به منظور پیش­بینی دما و تنش و سپس عمر خستگی کم­چرخه با استفاده از تئوری مارو و نرم­افزار ANSYS nCode Design Life انجام شده است. ثابت­های سخت شوندگی سینماتیک و همگن آلیاژ منیزیم AZ91با استفاده از تست­های خستگی کم­چرخه در دماهای مختلف محاسبه گردید. تست­های خستگی کم­چرخه به وسیله نرم­افزار انسیس شبیه­سازی شد و نشان داده شد که انطباق بسیار مناسبی بین نتایج تجربی و شبیه­سازی شده تست­های خستگی وجود دارد. نتایج تحلیل حرارتی نشان داد که جایگزینی آلیاژ منیزیم AZ91 با آلیاژ آلومینیم A356 باعث افزایش دمای سرسیلندر درحدود 23 درجه سانتیگراد می­شود. باتوجه به نتایج تحلیل ترمومکانیکی، هرچند سرسیلندر منیزیمی دمای بیشتری نسبت به سرسیلندر آلومینیمی تحمل می­کند اما حدود 13 مگاپاسکال تنش وان مایسس کمتری نسبت به سرسیلندر آلومینیمی تحمل می­کند. بنابراین آلیاژ منیزیم AZ91 می­تواند جایگزین مناسبی برای آلیاژ آلومینیم A356 باشد. عمر خستگی کم­چرخه سرسیلندر آلومینیمی و منیزیمی به­ترتیب 1799 و 1930 سیکل در ناحیه بحرانی پل بین سوپاپ­های گاز پیش­بینی گردید. نتایج تحلیل عمر خستگی کم­چرخه سرسیلندر نشان داد که جایگزینی آلیاژ منیزیم AZ91 با آلیاژ آلومینیم A356 باعث افزایش عمر خستگی کم­چرخه سرسیلندر حدود 7.3 درصد می­شود.
کلیدواژه‌ها
سرسیلندر
آلیاژ آلومینیم
آلیاژ منیزیم و عمر خستگی کم چرخه

موضوعات

عنوان مقاله English

The Effect of Changing Cylinder Head Material from Aluminium Alloy to Magnesium Alloy on its Low Cycle Fatigue Life

نویسنده English

Hojjat Ashouri
Islamic Azad University, Varamin
چکیده English

The cylinder head is one of the fundamental and challenging components in the engine, in which the thermo-mechanical stresses due to the fatigue effectively impart in its damage and reduction of its fatigue life. The present study aims to evaluate the low cycle fatigue (LCF) life of the cylinder head by altering its material from A356 aluminium alloy to AZ91 magnesium alloy. The present study used the finite element method to analyze the LCF life. The ANSYS software was also used to predict the temperature, stresses, and LCF life through Morrow theory and nCode Design Life software. The LCF tests were conducted at different temperatures to obtain the Kinematic and isotropic hardening constants of AZ91magnesium alloy. LCF tests were simulated by ANSYS software, showing a very good fit between the experimental and simulation results of LCF tests. According to the thermal analysis results, the substitution of AZ91 magnesium alloy leads to an increment in the cylinder head temperature by approximately 23ºC. The thermo-mechanical analysis suggested that even though the magnesium cylinder head tolerates higher temperatures, its toleration of Von-Mises stress is lower than the aluminiu m one (by about 13 MPa). Therefore, the AZ91 magnesium alloy can be considered an appropriate substitute for the A356 aluminium alloy. The low cycle fatigue life of aluminium and magnesium cylinder heads was predicted as 1799 and 1930 cycles in the critical area between the inlet valves, respectively. The low cycle fatigue life analysis of the cylinder head demonstrated that substituting AZ91 magnesium alloy with A356 aluminium alloy can increase the cylinder head's LCF life by about 7.3%.

کلیدواژه‌ها English

Cylinder Head
Aluminium Alloy
Magnesium Alloy
Low Cycle Fatigue Life
[1] Liu Y, Annabattula P, Mirmiran S, Zhang L, Chen J, Gaikwad S, Singh K. Assessing Thermo-mechanical Fatigue of a Cast Aluminum Alloy Cylinder Head of an Internal Combustion Engine. SAE Technical Paper No.2020-01-1077. 2020.
[2] Hazime R, Chang CC, Wang Q, Sochor S. Thermomechanical Fatigue Life Predictions of Cast Aluminum Cylinder Heads Considering Defect Distribution. SAE Technical Paper No. 2023-01-0594. 2023.
[3] Tharumarajah A, Koltun P. Is there an environmental advantage of using magnesium components for light-weighting cars, Journal of Cleaner Production. 2007;15:1007-1013.
[4] Mathaudhu SN, Luo AA, Neelameggham NR, Nyberg EA, Sillekens WH. Essential Readings in Magnesium Technology, Wiley Press, 2016.
[5] Azadi M, Farrahi GH, Zahedi F. Low cycle fatigue analysis of magnesium alloy cylinder head based on plastic strain energy approach. The Journal of Engine Research. 2012;27:3-10
[6] Azadi M, Mafi A, Roozban M, Moghaddam F. Failure analysis of a cracked gasoline engine cylinder head. Journal of Failure Analysis and Prevention. 2012;12:286-294.
[7] Ashouri H, Beheshti B, Ebrahimzadeh MR. Analysis of fatigue cracks of diesel engines cylinder heads. Journal of theoretical and applied mechanic. 2015;54(1): 369-383.
[8] Ashouri H. Thermo-mechanical analysis of magnesium alloy diesel engines cylinder heads using a two-layer viscoplasticity model. Automotive Science Engineering. 2022;12(3):3892-3904.
[9] Yang W, Pang J, Wang L, Kang X, Zhou S, Zou C, Li S, Zhang Z. Thermo-mechanical fatigue life prediction based on the simulated component of cylinder head. Engineering Failure Analysis. 2022;135:1-13.
[10] Basiri A, Amini E, On the Service Life Prediction of Diesel Engine Cylinder Head under Thermomechanical Fatigue Loading with Several Damage Models: A Comparative Study. Automotive Science and Engineering. 2022;12(1):3772-3786.
[11] Luo X, Zeng X, Zou P, Lin Y, Wei T, Yuan X, Liao S. A finite element analysis computational fluid dynamics coupled analysis on thermal-mechanical fatigue of cylinder head of a turbo-charged diesel engine. Journal of Automobile Engineering. 2019; 234(6):1-10.
[12] Hazime R, Seifert T, Kessens J. Lifetime Assessment of Cylinder Heads for Efficient Heavy Duty Engines Part II: Component-Level Application of Advanced Models for Thermomechanical Fatigue Life Prediction of Lamellar Graphite Cast Iron GJL250 and Vermicular Graphite Cast Iron GJV450 Cylinder Heads. SAE Technical Paper No. 2017-01-0346. 2017.
[13] Jing G, Li S, Xiao S, Ma T, Lyu Z, Sun S, Zhou H. Research on fatigue reliability assessment of engine cylinder head based on neural network. International Journal of Fatigue. 2023;175:1-19.
[14] Li Y, Liu J, Zhong G, Huang W, Zou R. Analysis of a diesel engine cylinder head failure caused by casting porosity defects. Engineering Failure Analysis. 2021;127:1-14.
[15] Ashouri H. Evaluation of quenching process on low cycle fatigue life for cylinder head. Automotive Science Engineering. 2022;12(4):3971-3979.
[16] Ashouri H. Low cycle fatigue prediction for cylinder heads considering stress gradient and local yielding. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering. 2024.
[17] Huang F, CAI W, Zhang Z, Zhang W, Shi L, Li X, Kaltenegger B, Suzzi D, Schrei W, Weihrauch K. Cylinder Head Structure Optimization Simulation Study based on Sub-Model Method. SAE Technical Paper No.2017-01-2433. 2017.
[18] Zhang H, Cui Y, Liang G, Li L, Zhang G, Qiao X. Fatigue life prediction analysis of high intensity marine diesel engine cylinder head based on fast thermal fluid solid coupling method. Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2021.
[19] Mahajan P, Thakur A, Bodake R. Correlation of Experimental Thermal Mapping and FEA Thermal Simulation for Cylinder Head for Diesel Engine Development. SAE Technical Paper No.2020-28-0353. 2020.
[20] Seifert T, Hazime R, Chang CC, Hu C, Constitutive Modeling and Thermo-mechanical Fatigue Life Predictions of A356-T6 Aluminum Cylinder Heads Considering Ageing Effects. SAE Technical Paper No.2019-01-0534. 2019.
[21] Zeng X, Luo X, Jing G, Zou P, Lin Y, Wei T, Yuan X, Ge H. Engine Cylinder Head Thermal-Mechanical Fatigue Evaluation Technology and Platform Application. SAE International Journal of Engines. 2020;13(1):101-120.
[22] Pingale A, Chang CC, Perander J. Data Driven Model to Predict Cylinder Head Fatigue Failure. SAE Technical Paper No. 2021-01-0801. 2021.
[23] Ren PR, Song W, Zhong G, Huang WQ, Zuo ZX, Zhao CZ, Yan KJ. High-cycle fatigue failure analysis of cast Al-Si alloy engine cylinder head. Engineering Failure Analysis. 2021;127:1-15.
[24] Blondet H, Barthoux K. Fatigue software improvement for calculating by FEA a complete map of the damage due to a duty cycle, regarding thermo-mechanical failure mode. Procedia Structural Integrity. 2022;38:526–537.
[25] Mahajan P, Bodake R, Thakur A. Optimization of Scallop Design for Cylinder Head of a Multi-Cylinder Diesel Engine for Reduction of Combustion Deck Temperatures and Simultaneously Enhancing Combustion Deck Fatigue Margin. SAE Technical Paper 2021-01-1233. 2021. doi:10.4271/2021-01-1233.
[26] Beranger M, Fiark JM, Ammar K, Calletaud G. A new fatigue model including thermal ageing for low copper aluminum-silicon alloys. Procedia Engineering. 2018;213:720-729.
[27] Azadi M, Mokhtari Shirazabad M, Boutorabi SMA, Nikravan M. An Investigation of High Cycle Fatigue Behavior of Magnesium Alloy for Cylinder Head Application. The Journal of Engine Research. 2011; 24:29-35.
[28] Azadi M, Basiri A, Moghaddam F. Finite element analysis of fatigue damage in passenger-car diesel engine cylinder head under cyclic thermo-mechanical loadings. The Journal of Engine Research. 2018;51:3-19.
[29] Chaboche JL, A review of some plasticity and viscoplasticity constitutive theories. International Journal of Plasticity. 2008;24:1642–1693.
[30] Stephens R, Fatemi A, Fuchs H. Metal fatigue in engineering. John Wiley, 2001
[31] Ashouri H. Effect of viscosity stress on the low cycle fatigue of the cylinder head. Amirkabir Journal of Mechanical Engineering. 2024;58(6):1053-1074
[32] Zhang Q, Zuo Z, Liu J. Failure analysis of a diesel engine cylinder head based on finite element method. Engineering Failure Analysis. 2013;34:51–58.
مهندسی مکانیک مدرس
دوره 25، شماره 2
بهمن 1403
صفحه 77-86