• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1078-1080
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• 2002

The pressure variation of interstitial fluid is one of the most important factors in bone physiology. In order to understand the role of interstitial fluid and the biomechanical interactions between fluid and solid constituents within bone, poroelastic theory was applied. The purpose of this study is to describe the behavior of calf vertebral trabecular bone composed of the porous solid trabeculae and the viscous bone marrow by using a commercial finite element analysis program based on the poroelasticity. In this study, the model was numerically tested for 5 different strain rates, i. e., 0.001, 0.01, 0.1, 1.0, and 10 per second. The material properties of the calf vertebral trabecular bone were utilized from the previous experimental study. Two asymptotic poroelastic response, the drained and undrained deformation, were predicted. From the predicted results for the simulated five strain rate, it was found that the pore pressure generation has a linearly increasing behavior when the strain rate is the highest at 10 per second, other wise it showed a nonlinear the strain rate Increased. Based on the results of the present study, it was suggested that the calf vertebral trabecular bone could be modeled as a porous material and its strain rate dependent material behavior could be predicted.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1038-1041
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• 2004

In this study, developed a micro-level experimental setup to measure pore pressure and poroelastic modulus in various strain and strain rate about a stress in micro-structure of bone tissue. It is essential device in the development of the model to analysis the interstitial bone fluid flow of the lacuno-canalicular system to be known that would effect on the bone remodeling. The constitution of the experimental setup is as follows, microscopic image processing system; actuator control unit; load measurement system. A pilot study was used an artificial chemical wood to have similar poroelastic property of bone matrix and conducted to validate the suitability of the measurement system.

• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.183-194
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• 2017

When a borehole is drilled, the load distributed by the removal is taken to re-establish equilibrium. As a result, the stresses around the borehole is redistributed. If there is no hydrostatic support pressure by drilling fluid (mud) introduced into the borehole, failure in the formation may take place. The mud pressure boundary that keeps the borehole stable is defined as a mud window. To predict the potential for failures around the borehole, a series of numerical analysis were performed and compared with a mud window. The effect of failure criterion and the intial stress ratio adopted on the mud window was also studied.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.527-534
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• 2014

Poroelastic analyses of fiber-reinforced composites were performed using image-based computational models. The section image of a porous matrix was analyzed in order to investigate the porosity, number of pores, and distribution of pores. The resolution, location, and size of the section image were considered to quantify the effective elastic modulus, poroelastic parameter, and strain energy density using the image-based computational models. The poroelastic parameter was calculated from the effective elastic modulus and pore pressure-induced strain. In addition, the results of the poroelastic analyses were verified through representative volume elements by simplifying various pore configurations and arrangements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.2
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• pp.92-98
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• 2017

Porosity in polymer matrix composites generated during pyrolysis process affect the thermomechanical behavior of the composites. In this paper, multislice finite element models for the porous composite materials are developed, and poroelastic and failure analysis for these models are performed. In order to investigate the three-dimensional effects, finite element meshes are modeled considering different porosity(up to 0.5) and the number of slices (up to five). As a result, effective Young's moduli and poroelastic parameters exhibit the maximum differences of 74.0% and 442.1% with respect to porosity respectively, and 98.7% and 37.2% with respect to the number of slices. First and last failure strengths are decreased 88.2% and 90.0% with respect to porosity respectively, and 53.8% and 171.8% with respect to the number of slices.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.1032-1040
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• 2001

It is widely accepted that the pressure variation of interstitial fluid is one of the most important factors in bone physiology. In order to understand the role of interstitial fluid on porous bony structure, a consideration for the biomechanical interactions between fluid and solid constituents within bone is required. In this study, a poroelastic theory was applied to investigate the elastic behavior of calf vertebral trabecular bone composed of the porous solid trabeculae and the viscous bone marrow. The poroelastic behavior of trabecular bone in a uniaxial stress condition was simulated using a commercial finite difference analysis software (FLAC, Itasca Consulting Group, USA), and tested for 5 different strain rates, i.e., 0.001, 0.01, 0.1, and 10 per second. The material properties of the calf vertebral trabecular bone were utilized from the previous experimental study. Two asymptotic poroelastic responses, the drained and undrained deformations, were predicted. From the predicted results for the simulated five strain rates, it was found that the pore pressure generation has a linearly increasing behavior when the strain rate is the highest at 10 per second, otherwise it showed a nonlinear behavior. The pore pressure generation with respect to the strain was found to be increased as the strain rate increased. The elastic moduli predicted at each strain were 208.3, 212.2, 337.6, 593.1, and 602.2 MPa, respectively. Based on the results of the present study, it was suggested that the calf vertebral trabecular bone could be modeled as a poroelastic material and its strain rate dependent material behavior could be predicted.

• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.5-16
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• 2002

A hydrogeomechanical numerical model is presented to evaluate rainfall impacts on groundwater flow in slopes and slope stability. This numerical model is developed based on the fully coupled poroelastic governing equations for groundwater flow in deforming variably saturated geologic media and the Galerkin finite element method. A series of numerical experiments using the model developed are then applied to an unsaturated slope under various rainfall rates. The numerical simulation results show that the overall hydromechanical slope stability deteriorates, and the potential failure nay initiate from the slope toe and propagate toward the slope crest as the rainfall rate increases. From the viewpoint of hydrogeology, the pressure head and hence the total hydraulic head increase as the rainfall rate increases. As a result, the groundwater table rises, the unsaturated zone reduces, the seepage face expands from the slope toe toward the slope crest, and the groundwater flow velocity increases along the seepage face. From the viewpoint of geomechanics, the horizontal displacement increases, and the vertical displacement decreases toward the slope toe as the rainfall rate increases. This may result from the buoyancy effect associated with the groundwater table rise as the rainfall rate increases. As a result, the overall deformation intensifies toward the slope toe, and the unstable zone, in which the factor of safety against shear failure is less than 1, becomes thicker near the slope toe and propagates from the slope toe toward the slope crest. The numerical simulation results also suggest that the potential tension failure is likely to occur within the slope between the potential shear failure surface and the ground surface.