Son K. Hoang

Geomechanics field characterization of woodford Shale and Barnett Shale with advanced logging tools and nano-indentation on drill cuttings

The Woodford Shale and Barnett Shale have emerged as prolific gas plays in the US midcontinent. However, the intrinsically low permeability of these gas shales hinders profitable pro-duction unless horizontal well drilling and multistage hydraulic fracturing are employed. The success of these operations depends on accurate de-terminations of the anisotropic elastic and poroelastic properties of these shale formations.

Correspondence principle between anisotropic poroviscoelasticity and poroelasticity using micromechanics and application to compression of orthotropic rectangular strips

In this paper, the correspondence principle between poroviscoelasticity and poroelasticity in both time domain and Laplace transform domain is established for the general case of matrix anisotropy as well as solid constituent anisotropy using micromechanics considerations. Using this correspondence principle, any constitutive relation or formula for material coefficient of linear anisotropic poroviscoelasticity can be obtained from the corresponding expression in poroelasticity. Numerical examples of the complex behavior of the poroviscoelastic Biot’s effective stress coefficient for geomaterials and biomaterials are included as illustration. Moreover, analytical solutions for initial and boundary value problems in the Laplace transform domain in poroelasticity can now be readily transferred to poroviscoelasticity and vice versa. To illustrate this technique, analytical solutions for orthotropic poroelastic rectangular strips under either unconfined compression (Mandel’s problem) or confined compression (...

Extended Green’s Solution for the Stresses in an Infinite Plate With Two Equal or Unequal Circular Holes

The distribution of stress in an isotropic and infinitely large plate perforated by circular holes has long attracted attention from both mathematical and engineering standpoints. Unfortunately, almost all existing solutions are only applicable to stress-free conditions at the boundary of the holes, which is not always the case in engineering applications. In an attempt to cover a wider range of applications, this paper presents the exact explicit solution for the stress distribution in an infinite plate containing two equal/unequal circular holes subjected to general in-plane stresses at infinity and internal pressures inside the holes, following the approach proposed by Green (1940, “General Bi-Harmonic Analysis for a Plate Containing Circular Holes ,” Proc. R. Soc. London, Ser. A, 176(964), pp. 121–139). The newly derived general solution has been verified not only with published solutions for special cases but also qualitatively with a comparable experimental testing program. In addition, some numerical examples are also provided to offer insight into the complexity of the interplay of parameters.

Inclined Direct Shear Testing Device: A New Tool for Bone Mechanics and Osteoporosis Research

Shear properties and strength are crucial for osteoporotic hip and wrist fracture risk assessment. This paper presents the design of a newly developed testing device for bone mechanical properties under circulation of different fluids. The device will ultimately be used to actively modify bone mineral content and porosity to simulate different stages of osteoporosis and directly measure the corresponding changes in mechanical properties. Preliminary results on intact bovine cancellous bones without fluid circulation showed excellent agreement with published literature data.Copyright