Measurement of Stress Network in Granular Materials from Infrared Measurement
Infrared thermography (IR) was used in this work that aims to experimentally evidence the stress network in granular media composed of two materials featuring different stiffness, without cohesion and under confined compression. Cylinders of polyoxymethylene (POM) and high-density polyethylene (HDPE) were used to build 2D composite granular systems. Cylinders were placed parallely and mixed together in a square metallic frame. The experiments were performed using a uniaxial testing machine. The granular media were first compacted in order to reach static equilibrium configurations. A cyclic compressive load was then applied. IR camera was employed to measure the temperature changes due to thermoelastic coupling on the cylinder network cross-sections. Temperature variations were then processed to obtain the maps of the amplitude of the sum of the principal stresses during the cycles. Three configurations were tested by changing the ratio between the POM and HDPE diameters and the ratio between the numbers of POM and HDPE cylinders. The experimental technique enables us to identify the stress network within the granular media. The experimental results are compared with numerical results obtained with a molecular dynamics software.
KeywordsGranular material Infrared thermography Thermoelastic stress analysis Stress network Confined compression
The authors gratefully acknowledge the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program (Grant No. PHD/0159/2552) and French Embassy in Thailand for their support during this research.
- 1.Dantu P (1957) Contribution à l’étude mécanique et géométrique des milieux pulvérulents. Proceedings of the 4th International Conference on Soil Mechanics and Foundation Engineering, tome 1, Butterworth, London, 144–148Google Scholar
- 3.Dijkstra J, Broere W (2010) New method of full-field stress analysis and measurement using photoelasticity. Geotech Test J 33:469–481Google Scholar
- 8.Słomiński C, Niedostatkiewicz M, Jacek T (2006) Deformation measurements in granular bodies using a particle image velocimetry technique. Arch Hydro-Eng Environ Mech 53:71–94Google Scholar
- 15.Fruehmann RK, Dulieu-Barton JM, Quinn S, Peton-Walter J, Mousty PAN (2012) The application of thermoelastic stress analysis to full-scale aerospace structures, Conference on Modern Practice in Stress and Vibration Analysis (MPSVA 2012). J Physics Conf Series 382, Article Number: 012058Google Scholar
- 17.Preechawuttipong I, Peyroux R, Radjai F (2001) Microscopic features of cohesive granular media, 4th International Conference on the Micromechanics of Granular, Kishino Y. (ed.), Powders and Grains 2001, 43–46Google Scholar