Paper contribution

Bonded Contact Calibration in DEM using Nano Indentation Test

Yogeshwar Murugesan; V B Maji

Proceedings
EUROCK 2026
Pages
553-560
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

Numerical investigation of crack propagation in rock materials has progressed considerably, with the Discrete Element Method (DEM) providing notable advantages over continuum-based methods in rock mechanics. Particle Flow Code (PFC), an explicit DEM tool, simulates rock behaviour through bonded contact models that describe interactions between rigid particles. Conventionally, calibration of these models relies on a trial-and-error approach, where micro-scale parameters are repeatedly adjusted to reproduce experimentally observed macro-mechanical properties. However, such methods often fail to accurately capture crack initiation from pre-existing flaws and the resulting failure patterns in numerical simulations. The Flat-Jointed Model (FJM) is widely adopted due to its ability to realistically represent the angular and interlocked nature of mineral grains in rock. Nevertheless, calibrating the six required micro-parameters in FJM is complex, time-consuming, and subject to uncertainty. To address this limitation, nano-indentation testing is utilized to directly estimate key micro-mechanical properties, including Young’s modulus and stiffness ratio. Using these parameters, crack propagation in flawed synthetic rock specimens under uniaxial loading is simulated in PFC. Validation of the numerical results demonstrates that the proposed calibration approach effectively captures crack growth and reproduces experimentally observed failure patterns with improved accuracy.

Contributors

Authors

  1. Yogeshwar Murugesan Research Scholar, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai -600036.
  2. V B Maji Professor, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai -600036.

Index terms

Keywords

Full text

Attachments

Works cited

References

  1. Bahaaddini M, Sheikhpourkhani AM, Mansouri H (2021) Flat-joint model to reproduce the mechanical behaviour of intact rocks. European Journal of Environmental and Civil Engineering 25(8): 1427–1448.
  2. Ganneau FP, Constantinides G, Ulm FJ (2006) Dual-indentation technique for the assessment of strength properties of cohesive-frictional materials. International Journal of Solids and Structures 43(6): 1727–1745. DOI.
  3. Itasca Consulting Group Inc (2014) PFC (Particle Flow Code) Version 5.0. Itasca Consulting Group Inc, Minneapolis, United States.
  4. Liu XY, et al. (2024) Study on the micromechanical and crack characteristics of granite based on nano indentation test and discrete element method. Computational Particle Mechanics 11(4): 1547–1563. DOI.
  5. Potyondy DO (2012) A flat-jointed bonded-particle material for hard rock. 46th US Rock Mechanics/Geomechanics Symposium, Chicago, United States, 2012, pp 1510–1519.
  6. Potyondy DO, Cundall PA (2004) A bonded-particle model for rock. International Journal of Rock Mechanics and Mining Sciences 41(8): 1329–1364. DOI.
  7. Yang H, Luo S, Zhang G, Song J (2017) Elasticity of clay shale characterized by nanoindentation. ARMA US Rock Mechanics/Geomechanics Symposium, San Francisco, United States, June 2017.
  8. Yang X, Zhang Y, Li G, Li Z, Feng J, Wang K (2024) Mesoscopic modeling approach and application based on rock thin slices and nanoindentation. Computers and Geotechnics 165: 105875.