Metallurgical Engineering

Metallurgical Engineering

Numerical and Experimental Investigations on Fatigue Behavior of a Carabiner made from Al-7175

Document Type : Research Paper

Authors
Negah Parsi 1
Bagher Mohammad Sadeghi 2
Hossein Arabi 3
Bahman Mirzakhani 4
1 M.S.c, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.
2 Assistant professor, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.
3 Professor, School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.
4 Associate professor, Department of Materials Science and Engineering, Faculty of Engineering, Arak University, Arak, Iran.
10.22076/me.2022.533306.1322
Abstract
Fatigue behavior of GUARDO Carabiner made from Al-7175 was investigated in this study. Monotonic tensile test with a cross-head speed of 35 mm.min-1 was applied on one of the Carabiners, before application of fatigue test on a similar Carabiner under a load range of 0-15 kN and a frequency of 2 Hz using a Falling Factor of 2 (this is equivalent to the free fall of a person with 120 kg weight whom attached to a rope and falls from a hight of 6 m). Under the above-mentioned condition, the fatigue life of the Carabiner was 2227 cycles. Fatigue fracture surface of the Carabiner was also examined by Scanning Electron Microscope. The results of fractography showed the formation of all the three stages of fatigue cracking as expected, as well as the presence of secondary cracks in the vicinity of brittle phases. A geometrical model of the Carabiner was designed using CATIA and specific mesh size applied on it in ABAQUS software. Simulations via ABAQUS were performed for various cyclic tensile load ranges (3, 9, 13, 15, 21 kN) with a frequency of 2 Hz. The output data for each simulation were used as input data in FE-safe software in order to estimate the fatigue life of Carabiner model. In FE-safe software, fatigue properties of Al-7175 were estimated and then Manson-Coffin-Basquin equation was used for prediction of fatigue life of carabiner for each cyclic tensile loading. Finally, a mathematical model was proposed in order to predict the relationship between the applied force and the number of cycles to failure.
Keywords
Carabiner
Aluminium Alloy 7175
Fatigue Behavior
FEM Simulation
Fractography
  1. Hui W, LUO Y, Friedman P, CHEN M, Lin GAO. Warm forming behavior of high strength aluminum alloy AA7075. Trans Nonferrous Met Soc China. Elsevier; 2012;22(1):1–7.
  2. Lim ST, Yun SJ, Nam SW. Improved quench sensitivity in modified aluminum alloy 7175 for thick forging applications. Mater Sci Eng A. Elsevier; 2004;371(1–2):82–90.
  3. Lim ST, Eun IS, Nam SW. Control of equilibrium phases (M, T, S) in the modified aluminum alloy 7175 for thick forging applications. Mater Trans. The Japan Institute of Metals and Materials; 2003;44(1):181–7.
  4. Li J-F, Peng Z, Li C-X, Jia Z-Q, Chen W, Zheng Z-Q. Mechanical properties, corrosion behaviors and microstructures of 7075 aluminium alloy with various aging treatments. Trans Nonferrous Met Soc China. Elsevier; 2008;18(4):755–62.
  5. Dursun T, Soutis C. Recent developments in advanced aircraft aluminium alloys. Mater Des. Elsevier; 2014;56:862–71.
  6. Vu C, Wern C, Kim B-H, Kim SK, Choi H-J, Yi S. Fatigue characteristic analysis of new ECO7175v1 extruded aluminum alloy. J Aerosp Eng. American Society of Civil Engineers; 2019;32(1):4018128.
  7. Silva FS, Pinho ACM. The effect of temperature on crack behavior in an 7175 aluminum alloy under mode I+ steady mode III. In: European Structural Integrity Society. Elsevier; 2002. p. 247–56.
  8. DuQuesnay DL, Underhill PR. Fatigue life scatter in 7xxx series aluminum alloys. Int J Fatigue. Elsevier; 2010;32(2):398–402.
  9. Ghalehbandi SM, Fallahi‐Arezodar A, Hosseini‐Toudeshky H. Fatigue crack growth resistance of 7075 Al alloy after equal channel angular pressing. Fatigue Fract Eng Mater Struct. Wiley Online Library; 2016;39(12):1517–25.
  10. Haake S. The engineering of sport: design and development. In Blackwell Science; 1998. p. 7–161.

11.The Carabiner Handbook [Internet]. [cited 2021 Oct 8]. Available from: https://www.climbing.com/gear/the-carabiner-handbook/

  1. “A History of Rock Climbing Gear Technology and Standards” by Casandra Marie Bright [Internet]. [cited 2021 Oct 15]. Available from: https://scholarworks.uark.edu/meeguht/41/
  2. Astm F 1774 – 99 pdf free download - CIVIL STANDARDS [Internet]. [cited 2021 Oct 15]. Available from: https://allcivilstandard.com/astm-f-1774-99-pdf-free-download/
  3. Nergiş DPB, Nejneru C, Achiţei DC, Cimpoieşu N, Bejinariu C. Structural Analysis of Carabiners Materials Used at Personal Protective Equipments. In: IOP Conference Series: Materials Science and Engineering. IOP Publishing; 2018. p. 12040.
  4. Blair KB, Custer DR, Graham JM, Okal MH. Analysis of fatigue failure in D-shaped karabiners. Sport Eng. Springer; 2005;8(2):107–13.
  5. Aliha MRM, Bahmani A, Akhondi S. Fracture and fatigue analysis for a cracked carabiner using 3D finite element simulations. Strength Mater. Springer; 2015;47(6):890–902.
  6. Aluminium Association. International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys with Support for On-line Access From: Aluminum Extruders Council Use of the Information. Alum Assoc Arlington, Virginia. 2015;31.
  7. ASTM E8 / E8M - 21 Standard Test Methods for Tension Testing of Metallic Materials. (n.d.). Retrieved November 4, 2021, from https://www.astm.org/Standards/E8.htm
  8. Pavier M. Experimental and theoretical simulations of climbing falls. Sport Eng. Wiley Online Library; 1998;1(2):79–91.
  9. Meriam JL, Kraige LG, Bolton JN. Engineering mechanics: dynamics. John Wiley & Sons; 2020.
  10. Alloys H-SAPM. Properties and selection: nonferrous alloys and special-purpose materials. 1998;2:62–122.
  11. Young’s Modulus - Tensile and Yield Strength for some common Materials [Internet]. [cited 2021 Oct 8]. Available from: https://www.engineeringtoolbox.com/young-modulus-d_417.html
  12. Abaqus 2020 [Internet]. [cited 2021 Oct 15]. Available from: https://www.3ds.com/support/hardware-and-software/simulia-system-information/abaqus-2020/
  13. Park J-H, Song J-H. Detailed evaluation of methods for estimation of fatigue properties. Int J Fatigue. Elsevier; 1995;17(5):365–73.
  14. Manson SS. Fatigue: a complex subject—some simple approximations. Exp. Mech. Springer; 1965;5(4):193–226.
  15. fe-safe | SIMULIA Durability Analysis Software [Internet]. [cited 2021 Oct 8]. Available from: https://www.3ds.com/products-services/simulia/products/fe-safe/

  • Receive Date 03 July 2021
  • Revise Date 18 December 2021
  • Accept Date 24 January 2022