بررسی تاثیر عمق نفوذ و سرعت دیسک برنیروهای برش سنگ بر اساس نتایج شبیه‌سازی با نرم‌افزار LS-DYNA

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی معدن، دانشگاه صنعتی امیرکبیر، تهران، ایران

2 شرکت تونل‌ساز ماشین، تهران، ایران

چکیده

نیروهای اعمال شده به دیسک‌های برشی از جمله مهم‌ترین پارامترهای طراحی ماشین‌های حفار در زمین‌های سخت هستند. این نیروها شامل نیروی عمودی و غلطشی می‌باشند. برای طراحی ماشین حفار نیاز به بررسی دقیق نیرو‌های یادشده می‌باشد که تحت تاثیر عواملی چون عمق نفوذ، فاصله‌داری، سرعت خطی و چرخشی دیسک تغییر می‌کنند. از این رو نیاز به آزمایشات برش خطی برای درک تاثیر هریک از موارد یاد شده می‌باشد. از آنجا که آزمایشات برش خطی زمان‌بر و پرهزینه است شبیه‌سازی‌های عددی بادقت زیاد می‌تواند جایگزین مناسبی باشد. در این مقاله با استفاده از نرم‌افزار LS-DYNA ابتدا شبیه‌سازی‌های لازم برای اعتبارسنجی با بررسی دو مدل رفتاری جانسون هالمکوئیست بتن (JHC) و RHT انجام شده است. پس از این مرحله با تکیه بر تغییر متغیر‌هایی از جمله عمق نفوذ، سرعت خطی و چرخشی دیسک به بررسی تاثیر آن‌ها پرداخته شده است. بر اساس نتایج به دست آمده، عمق نفوذ پارامتری بسیار موثر بر نیروی عمودی است. با افزایش عمق نفوذ از 2/5 به 7/6 میلی‌متر نیروی عمودی از ۹۶ به ۱۵۹ کیلونیوتن می‌رسد. این نتیجه با تاثیری بیشتر برای نیروی غلطشی صادق می‌باشد، به این صورت که نیروی غلطشی از 6/1 به 22/5 کیلونیوتن افزایش می‌یابد. با افزایش سرعت خطی و چرخشی دیسک‌ها، نیروهای عمودی و غلطشی کاهش می‌یابد، اما مقدار این کاهش بسیار کم است. بر اساس نتایج به دست آمده، افزایش سرعت خطی از 0/33 به1/65 میلی‌متر تنها باعث کاهش ۱۳ درصدی نیروی عمودی (از ۱۵۵ به ۱۳۵ کیلونیوتن) و کاهش ۵ درصدی نیروی غلطشی (از 20/6 به 19/5 کیلونیوتن) می‌شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Study of the effect of penetration depth and disc speed on cutting forces using LS-DYNA simulations

نویسندگان [English]

  • Shahin Fatahi Dehkbodi 1
  • Ebrahim Farrokh 1
  • Davood Lotfi 2
1 Master's student in rock mechanics, Mining engineering department, Amirkabir university of technology
2 Master of mechanical engineering-applied design, Director of research and development of Tunnelsaz machine
چکیده [English]

The forces imparted upon cutting discs represent crucial design parameters for tunnel boring machines (TBMs) engaged in rock excavation processes. These forces comprise normal and rolling forces, which are influenced by factors including penetration depth, spacing, and linear and rotational velocity of the disc. Therefore, a careful examination of these forces is necessary for the design of effective TBMs. Linear cutting tests are time-consuming and financially prohibitive exercises. Consequently, precision numerical simulations can serve as a suitable alternative approach. In this report, the LS-DYNA software environment was employed to conduct simulations validating two constitutive models of concrete behavior: Johnson Holmquist (JHC) and RHT. The impact of variables such as penetration depth, and linear and rotational motion of the disc on exerted forces was investigated. The findings indicate penetration depth notably impacts both normal and rolling forces. Augmenting depth from 2.5mm to 7.6mm results in escalations of normal force from 96kN to 159kN and rolling force from 6.1kN to 22.5kN. As linear and rotational velocities of discs increase, forces decrease marginally. However, elevating linear speed from 0.33mm to 1.65mm precipitates merely a 13% reduction in normal force (from 155kN to 175kN) and 5% decrease in rolling force (from 20.6kN to 19.5kN), according to the results obtained.

کلیدواژه‌ها [English]

  • Disc Cutter
  • LS-DYNA simulation
  • LCM Test
  • normal force
  • rolling force
[1] J.-W. Cho, S. Jeon, S.-H. Yu, S.-H. Chang, Optimum spacing of TBM disc cutters: A numerical simulation using the three-dimensional dynamic fracturing method, Tunnelling and Underground Space Technology, 25(3) (2010) 230-244.
[2] R. Gertsch, L. Gertsch, J. Rostami, Disc cutting tests in Colorado Red Granite: Implications for TBM performance prediction, International Journal of rock mechanics and mining sciences, 44(2) (2007) 238-246.
[3] J. Rostami, L. Ozdemir, B. Nilson, Comparison between CSM and NTH hard rock TBM performance prediction models, in:  Proceedings of Annual Technical Meeting of the Institute of Shaft Drilling Technology, Las Vegas, 1996, pp. 1-10.
[4] J.-W. Cho, S. Jeon, H.-Y. Jeong, S.-H. Chang, Evaluation of cutting efficiency during TBM disc cutter excavation within a Korean granitic rock using linear-cutting-machine testing and photogrammetric measurement, Tunnelling and Underground Space Technology, 35 (2013) 37-54.
[5] S.-H. Chang, S.-W. Choi, G.-J. Bae, S. Jeon, Performance prediction of TBM disc cutting on granitic rock by the linear cutting test, Tunnelling and Underground Space Technology, 21(3) (2006) 271.
[6] J. Rosutami, A new model for performance prediction of hard rock TBMs, in:  Proceedings/1993 rapid excavation and tunneling conference, 1993.
[7] A. Bruland, Hard rock tunnel boring, performance data and back-mapping, Project report E, 1 (1998).
[8] F. Wang, L. Ozdemir, Tunnel-boring penetration rate and machine design, Transportation Research Record, (684) (1978).
[9] H. Sanio, Prediction of the performance of disc cutters in anisotropic rock, in:  International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, Elsevier, 1985, pp. 153-161.
[10] F.F. Roxborough, H.R. Phillips, Rock excavation by disc cutter, in:  International journal of rock mechanics and mining sciences & geomechanics abstracts, Elsevier, 1975, pp. 361-366.
[11] Y. Nishimatsu, The mechanics of rock cutting, in:  International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, Elsevier, 1972, pp. 261-270.
[12] J. Hassanpour, J. Rostami, J. Zhao, A new hard rock TBM performance prediction model for project planning, Tunnelling and Underground Space Technology, 26(5) (2011) 595-603.
[13] J. Hassanpour, J. Rostami, S.T. Azali, J. Zhao, Introduction of an empirical TBM cutter wear prediction model for pyroclastic and mafic igneous rocks; a case history of Karaj water conveyance tunnel, Iran, Tunnelling and underground space technology, 43 (2014) 222-231.
[14] E. Farrokh, J. Rostami, C. Laughton, Study of various models for estimation of penetration rate of hard rock TBMs, Tunnelling and Underground Space Technology, 30 (2012) 110-123.
[15] N.R. Barton, TBM tunnelling in jointed and faulted rock, Crc Press, 2000.
[16] S. Yagiz, Utilizing rock mass properties for predicting TBM performance in hard rock condition, Tunnelling and Underground Space Technology, 23(3) (2008) 326-339.
[17] Z. Zhao, Q. Gong, Y. Zhang, J. Zhao, Prediction model of tunnel boring machine performance by ensemble neural networks, Geomechanics and Geoengineering: An International Journal, 2(2) (2007) 123-128.
[18] P.L. Menezes, M.R. Lovell, I.V. Avdeev, J.-S. Lin, C.F. Higgs, Studies on the formation of discontinuous chips during rock cutting using an explicit finite element model, The International Journal of Advanced Manufacturing Technology, 70 (2014) 635-648.
[19] N. Innaurato, C. Oggeri, P.P. Oreste, R. Vinai, Experimental and numerical studies on rock breaking with TBM tools under high stress confinement, Rock Mechanics and Rock Engineering, 40 (2007) 429-451.
[20] I. Tulu, K. Heasley, Calibration of 3D cutter-rock model with single cutter tests, in:  ARMA US Rock Mechanics/Geomechanics Symposium, ARMA, 2009, pp. ARMA-09-160.
[21] X. Tan, S.Q. Kou, P.-A. Lindqvist, Application of the DDM and fracture mechanics model on the simulation of rock breakage by mechanical tools, Engineering Geology, 49(3-4) (1998) 277-284.
[22] C. Tang, Numerical simulation of progressive rock failure and associated seismicity, International Journal of Rock Mechanics and Mining Sciences, 34(2) (1997) 249-261.
[23] C. Tang, Y. Fu, S. Kou, P.-A. Lindqvist, Numerical simulation of loading inhomogeneous rocks, International Journal of Rock Mechanics and Mining Sciences, 35(7) (1998) 1001-1007.
[24] G. Li, B. Wang, Y.D. Chen, W.S. Wang, Numerical simulation of the rock fragmentation process induced by TBM cutters, Applied Mechanics and Materials, 249 (2013) 1069-1072.
[25] B. Yu, Numerical simulation of continuous miner rock cutting process, West Virginia University, 2005.
[26] M.C. Jaime, Numerical modeling of rock cutting and its associated fragmentation process using the finite element method, University of Pittsburgh, 2011.
[27] J.O. Hallquist, L.-D.T. Manual, Livermore software technology corporation, Livermore, Ca,  (1998) 94550-91740.
[28] J. Rostami, Development of a force estimation model for rock fragmentation with disc cutters through theoretical modeling and physical measurement of crushed zone pressure, Colorado School of Mines Golden, CO, USA, 1997.
[29] L. Hao, Y. Zhang, J. Cui, An Eulerian numerical method and its application to explosion problems, International Journal of Civil and Environmental Engineering, 6(8) (2012) 693-695.
[30] G.R. Johnson, T.J. Holmquist, An improved computational constitutive model for brittle materials, in:  AIP conference proceedings, American Institute of Physics, 1994, pp. 981-984.
[31] S.P. Shah, S.E. Swartz, C. Ouyang, Fracture mechanics of concrete: applications of fracture mechanics to concrete, rock and other quasi-brittle materials, John Wiley & Sons, 1995.
[32] M. Kucewicz, P. Baranowski, J. Małachowski, Dolomite fracture modeling using the Johnson-Holmquist concrete material model: Parameter determination and validation, Journal of Rock Mechanics and Geotechnical Engineering, 13(2) (2021) 335-350.
[33] H. Li, E. Du, Simulation of rock fragmentation induced by a tunnel boring machine disk cutter, Advances in Mechanical Engineering, 8(6) (2016) 1687814016651557.