بررسی تجربی جذب انرژی پروفیل‌های مربعی تحت بارگذاری دندانه‌ای چندگانه

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی مکانیک و هوافضا، دانشگاه صنعتی شیراز

چکیده

در این تحقیق به مطالعه تجربی جذب انرژی و تغییر شکل پروفیل‌های جدارنازک با سطح مقطع مربعی تحت بارگذاری دندانه‌ای چندگانه پرداخته شده است. هدف اصلی از انجام این تحقیق بررسی اثر تعداد دندانه‌ها و همچنین قطر و فاصله‌ی بین دندانه‌ها بر پارامترهای جذب انرژی است. در ابتدا پروفیل‌های مربعی آلومینیوم با طول مشخص تهیه شد و همچنین یک مجموعه دندانه قابل تنظیم نیز جهت اعمال بارگذاری دندانه‌ای چندگانه ساخته شد. سپس بارگذاری شبه استاتیکی با نرخ بارگذاری ثابت بر روی نمونه‌ها انجام گرفت. در نحوه‌ی بارگذاری، نمونه‌ها بین یک فک نسبتا صلب و یک مجموعه‌ی دندانه قابل تنظیم قرار گرفت. نمودارهای نیرو-جابه‌جایی نمونه‌ها به دست آمد و پارامترهای جذب انرژی محاسبه شد. مقایسه‌ی نتایج تجربی در حالت یک‌دندانه و دودندانه نشان دهنده افزایش قابل توجه جذب انرژی حالت دودندانه نسبت به یک دندانه بود. برای بارگذاری با دو دندانه، با افزایش فاصله دندانه‌ها از هم، نمودارهای نیرو-جابه جایی به مراتب بالاتر از حالت یک دندانه قرار گرفت و به حالت دو دندانه مجزا نزدیک شد. همچنین با افزایش قطر و فاصله‎ی بین دندانه‌ها به دلیل ایجاد لولای پلاستیک بزرگتر، میزان جذب انرژی حدود 20تا 60درصد افزایش یافت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Study of Energy Absorption of Square Column under Multi-Indentation Loading

نویسندگان [English]

  • J. Rouzegar
  • M. R. Keshavarz
  • H. Assaee
Department of Mechanical and Aerospace Engineering, Shiraz university of Technology, Shiraz, Iran
چکیده [English]

This research deals with experimental investigation on energy absorption and deformation of thin walled square columns under multi-indentation loading. The main goal of this research is to examine the effect of number and diameter of indenters and distance between them on the energy absorption parameters. First, square aluminum specimens with specific lengths were prepared and also an adjustable fixture for applying multi-indentation loading was fabricated. Then the indentation loading were applied on the specimens during a quasi-static condition with a constant loading rate. During loadings, the specimens were located between an almost rigid platen and the adjustable indenters. The load-displacement diagrams of specimens were obtained and the energy absorption parameters were calculated. The results indicate that the amount of absorbed energy in multi-indentation process increases significantly respect to single-indentation. By increasing the distance between indenters in multi-indentation loading, the load- displacement diagram shifts upward and moves toward the twice of single-indentation diagram. Also, by increment of diameter of indenters and distance between them, the amount of absorbed energy increases 20-60% due to formation of bigger plastic hinges.

کلیدواژه‌ها [English]

  • Experimental study
  • Energy Absorption
  • Thin-walled column
  • Indentation loading
  • Multi-indentation
[1] A. Alghamdi, Collapsible impact energy absorbers: an overview, Thin-walled structures, 39(2) (2001) 189-213.
[2] S.V. Hosseini, J. Zamani, A. Darvize, M. Soleimani, An experimental and numerical analysis of mechanical and geometrical characteristics effect on crush loading of square energy absorbers under axial loading, Mechanic and Aero Space, 2(2) (2006) 1-10 (in Persian).
[3] C. Karroum, S.R. Reid, S. Li, Indentation of ring-stiffened cylinders by wedge-shaped indenters—Part 1: An experimental and finite element investigation, International journal of mechanical sciences, 49(1) (2007) 13-38.
[4] W. Johnson, A. Walton, Protection of car occupants in frontal impacts with heavy lorries: Frontal structures, International Journal of Impact Engineering, 1(2) (1983) 111-123.
[5] W. Johnson, A. Walton, An experimental investigation of the energy dissipation of a number of car bumpers under quasi-static lateral loads, International Journal of Impact Engineering, 1(3) (1983) 301-308.
[6] J.D. Reid, D.L. Sicking, Design and simulation of a sequential kinking guardrail terminal, International journal of impact engineering, 21(9) (1998) 761-772.
[7] Y. Kanae, T. Sasaki, S. Shimamura, Experimental and analytical studies on the drop-impact test with lead-shielded scale model radioactive material shipping casks, in: Structural impact and crashworthiness. Volume 2, 1984.
[8] A. Alghamdi, Protection of Saudi descent roads using metallic collapsible energy absorbers, Final Report Submitted to KACST, Riyadh, Saudi Arabia, Grant, 98(2) (2000) 74.
[9] L. Mirfendereski, M. Salimi, S. Ziaei-Rad, Parametric study and numerical analysis of empty and foam-filled thin-walled tubes under static and dynamic loadings, International Journal of Mechanical Sciences, 50(6) (2008) 1042-1057.
[10] S. Reid, Metal tubes as impact energy absorbers, in: Metal forming and impact mechanics, Elsevier, 1985, pp. 249-269.
[11] A.A. Nia, H. Badnava, K.F. Nejad, An experimental investigation on crack effect on the mechanical behavior and energy absorption of thin-walled tubes, Materials & Design, 32(6) (2011) 3594-3607.
[12] K. Johnson, The correlation of indentation experiments, Journal of the Mechanics and Physics of Solids, 18(2) (1970) 115-126.
[13] V.-W. Shim, W. Stronge, Lateral crushing of thin-walled tubes between cylindrical indenters, International journal of mechanical sciences, 28(10) (1986) 683-707.
[14] G. Lu, A study of the crushing of tubes by two indenters, International journal of mechanical sciences, 35(3-4) (1993) 267-278.
[15] T. Wierzbicki, M. Suh, Indentation of tubes under combined loading, International Journal of Mechanical Sciences, 30(3-4) (1988) 229-248.
[16] C. Kardaras, G.X. Lu, Finite element analysis of thin walled tubes under point loads subjected to large plastic deformation, in: Key engineering materials, Trans Tech Publ, 2000, pp. 733-738.
[17] D.C. Brooker, A numerical study on the lateral indentation of continuously supported tubes, Journal of Constructional Steel Research, 60(8) (2004) 1177-1192.
[18] A.-G. Olabi, E. Morris, M. Hashmi, Metallic tube type energy absorbers: a synopsis, Thin-walled structures, 45(7-8) (2007) 706-726.
[19] F. Hafeez, F. Almaskari, Experimental investigation of the scaling laws in laterally indented filament wound tubes supported with V shaped cradles, Composite Structures, 126 (2015) 265-284.
[20] E. ASTM, 8M. Standard Test Methods of Tension Testing of Metallic Materials (Metric), Annual Book of ASTM Standards, in: Am Soc Testing Mater, 1999, pp. 01.
[21] Y. Xiang, T. Yu, L. Yang, Comparative analysis of energy absorption capacity of polygonal tubes, multi-cell tubes and honeycombs by utilizing key performance indicators, Materials & Design, 89 (2016) 689-696.