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In order to understand the fracture mechanisms of bone subjected to external force well, an experimental study has been performed on the bovine bone by carrying out the three-point bending test with 3D digital image correlation (DIC) method, which provides a noncontact and full field of displacement measurement. The local strain and damage evolution of the bone has been recorded real time. The results show that the deflection measured by DIC agrees well with that obtained by the displacement sensor of the mechanical testing machine. The relationship between the deflection and the force is nearly linear prior to reaching the peak strength which is about 16 kN for the tested bovine tibia. The full-field strain contours of the bone show that the strain distribution depends on not only the force direction, but also the natural bone shape. The natural arched-shape bovine tibia bone could bear a large force, due to the tissue structure with high strength, and the fracture propagation process of the sample initiates at the inner side of the bone first and propagates along the force direction.

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In this paper, an experimental study is presented that intended to investigate (1) the anisotropy properties of hydraulic conductivity of Boom Clay, (2) the effect of heating-cooling cycle on the hydraulic conductivity and intrinsic permeability of Boom Clay, and (3) the effect of loading-unloading cycle on the hydraulic conductivity and intrinsic permeability of Boom Clay. Constant-head tests were carried out in a temperature-controlled triaxial cell. First, the anisotropic characteristic of hydraulic conductivity of Boom Clay with respect to its bedding was confirmed. The horizontal hydraulic conductivity (parallel to bedding) is larger than the vertical hydraulic conductivity (perpendicular to bedding).Second, there was a positive and reversible relationship between the hydraulic conductivity and temperature and a negative and irreversible relationship between the hydraulic conductivity and hydrostatic pressure.Specifically, for both horizontal and vertical hydraulic conductivity, the value at 80 °C is approximately 2.4 times larger than that at room temperature (23 °C). However, it appears that the hydraulic conductivity is not sensitive to heating rate. Data analysis reveals that under variable temperature conditions, the changes in viscosity and density of water with temperature are the main factors affecting the change in hydraulic conductivity of Boom Clay with temperature, although other factors may have an effect to some extent.3

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