Streaming Potential Induced by Canaliculi Fluid Flow: A Fluid-Filled Thick-Walled Cylinder Osteon Model Subjected to Axial Loading

2010 ◽  
Vol 34-35 ◽  
pp. 117-122
Author(s):  
Xiao Gang Wu ◽  
Wei Yi Chen
Keyword(s):  
Fluid Flow ◽  
Streaming Potential ◽  
Axial Loading ◽  
Fluid Phase ◽  
Form Solution ◽  
Solid Matrix ◽  
Intraosseous Pressure ◽  
Elastic Transverse ◽  
Close Form ◽  
Walled Cylinder

Based on the physiological structure of osteon, a single fluid-filled osteon model under only time-dependent axial loading is modeled for calculating the streaming potential induced by canaliculi fluid flow. Solid matrix is modeled as an elastic transverse isotropic thick-walled cylinder and fluid phase is considered as an incompressible Newtonian fluid. Close-form solution of the streaming potential for a single osteon model was obtained and used to study the electromechanical properties on intraosseous pressure and potential distribution. The solution can also be used as a benchmark for numerical studies of other osteon models.

Oscillatory Compressional Behavior of Articular Cartilage and Its Associated Electromechanical Properties

1981 ◽  
Vol 103 (4) ◽  
pp. 280-292 ◽  
Author(s):  
R. C. Lee ◽  
E. H. Frank ◽  
A. J. Grodzinsky ◽  
D. K. Roylance
Keyword(s):  
Fluid Flow ◽  
Articular Cartilage ◽  
Molecular Mechanisms ◽  
Fluid Velocity ◽  
Streaming Potential ◽  
Usual Sense ◽  
Frequency Range ◽  
Confined Compression ◽  
Streaming Potentials ◽  
Compressive Stiffness

The compressive stiffness of articular cartilage was examined in oscillatory confined compression over a wide frequency range including high frequencies relevant to impact loading. Nonlinear behavior was found when the imposed sinusoidal compression amplitude exceeded a threshold value that depended on frequency. Linear behavior was attained only by suitable control of the compression amplitude. This was enabled by real time Fourier analysis of data which provided an accurate assessment of the extent of nonlinearity. For linear viscoelastic behavior, a stiffness could be defined in the usual sense. The dependence of the stiffness on ionic strength and proteoglycan content showed that electrostatic forces between matrix charge groups contribute significantly to cartilage’s compressive stiffness over the 0.001 to 20 Hz frequency range. Sinusoidal streaming potentials were also generated by oscillatory compression. A theory relating the streaming potential field to the fluid velocity field is derived and used to interpret the data. The observed magnitude of the streaming potential suggests that interstitial fluid flow is significant to cartilage behavior over the entire frequency range. The use of simultaneous streaming potential and stiffness data with an appropriate theory appears to be an important tool for assessing the relative contribution of fluid flow, intrinsic matrix viscoelasticity, or other molecular mechanisms to energy dissipation in cartilage. This method is applicable in general to hydrated, charged polymers.

Eulerian Multi-Fluid Model of Air Blast Atomization

2006 ◽  
Author(s):  
Srimani Bhamidipati ◽  
Mahesh Panchagnula ◽  
John Peddieson
Keyword(s):  
Closed Form ◽  
Recurrence Relations ◽  
Model Problem ◽  
Fluid Model ◽  
Closed Form Solution ◽  
Fluid Phase ◽  
Form Solution ◽  
Air Blast ◽  
Carrier Fluid ◽  
Selection Of

The application of fully Eulerian "multi-fluid" models to air blast atomization is discussed. Such models envision the system as consisting one carrier fluid phase and multiple drop phases, each having a discrete size. A model problem is formulated which allows a general closed form solution in terms of recurrence relations. This closed form solution is employed to produce representative results. A selection of these is used to illustrate interesting aspects of the predictions.

A New Close-Form Solution for Initial Registration of ICP

2010 ◽  
Vol 143-144 ◽  
pp. 287-292
Author(s):  
Li Zhao Liu ◽  
Xiao Jing Hu ◽  
Yu Feng Chen ◽  
Tian Hua Zhang ◽  
Mao Qing Li
Keyword(s):  
Closed Form Solution ◽  
Goal Function ◽  
Form Solution ◽  
Initial Value ◽  
Global Goal ◽  
Online Matching ◽  
Testing Algorithm ◽  
Close Form ◽  
Eigenvalue And Eigenvector ◽  
The Relationship

The paper proposed a original matching algorithm using the feature vectors of rigid points sets matrix and a online matching intersection testing algorithm using the bounding sphere. The relationship searching between points in each set is took place by the corresponding eigenvectors that is a closed form solution relatively. The affine transformed eigenvalue and eigenvector is also used instead of the affine transformed points sets for the non-rigid matching that do not need the complicated global goal function. The characteristics matching for the initial registration can give a well initial value for the surfaces align that improve the probability of global solution for the following-up ICP

scholarly journals FROM BOUNDARY CROSSING OF NON-RANDOM FUNCTIONS TO BOUNDARY CROSSING OF STOCHASTIC PROCESSES

2015 ◽  
Vol 29 (3) ◽  
pp. 345-359 ◽  
Author(s):  
Mark Brown ◽  
Victor de la Peña ◽  
Tony Sit
Keyword(s):  
Stochastic Processes ◽  
Sequential Analysis ◽  
Form Solution ◽  
Boundary Crossing ◽  
Renewal Processes ◽  
Bessel Processes ◽  
Average Behavior ◽  
Random Functions ◽  
Close Form ◽  
Sharp Lower Bound

One problem of wide interest involves estimating expected crossing-times. Several tools have been developed to solve this problem beginning with the works of Wald and the theory of sequential analysis. Deriving the explicit close form solution for the expected crossing times may be difficult. In this paper, we provide a framework that can be used to estimate expected crossing times of arbitrary stochastic processes. Our key assumption is the knowledge of the average behavior of the supremum of the process. Our results include a universal sharp lower bound on the expected crossing times. Furthermore, for a wide class of time-homogeneous, Markov processes, including Bessel processes, we are able to derive an upper bound E[a(Tr)]≤2r, which implies that sup r>0|((E[a(Tr)]−r)/r)|≤1, where a(t)=E[sup tXt] with {Xt}t≥0 be a non-negative, measurable process. This inequality motivates our claim that a(t) can be viewed as a natural clock for all such processes. The cases of multidimensional processes, non-symmetric and random boundaries are handled as well. We also present applications of these bounds on renewal processes in Example 10 and other stochastic processes.

Stress Distribution in and Around Spheroidal Inclusions and Voids at Finite Concentration

1986 ◽  
Vol 53 (3) ◽  
pp. 511-518 ◽  
Author(s):  
G. P. Tandon ◽  
G. J. Weng
Keyword(s):  
Stress Distribution ◽  
Energy Distribution ◽  
Uniaxial Tension ◽  
Elastic Stress ◽  
Three Dimensional ◽  
Tensile Loading ◽  
Form Solution ◽  
Finite Concentration ◽  
The Matrix ◽  
Close Form

A simple, albeit approximate, close-form solution is developed to study the elastic stress and energy distribution in and around spheroidal inclusions and voids at finite concentration. This theory combines Eshelby’s solution of an ellipsoidal inclusion and Mori- Tanaka’s concept of average stress in the matrix. The inclusions are taken to be homogeneously dispersed and undirectionally aligned. The analytical results are obtained for the general three-dimensional loading, and further simplified for uniaxial tension applied parallel to the axis of inclusions. The ensuing stress and energy fields under tensile loading are illustrated for both hard inclusions and voids, ranging from prolate to oblate shapes, at several concentrations.

The Bauschinger and Hardening Effect on Residual Stresses in an Autofrettaged Thick-Walled Cylinder

1986 ◽  
Vol 108 (1) ◽  
pp. 108-112 ◽  
Author(s):  
P. C. T. Chen
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Closed Form Solution ◽  
High Strength ◽  
Form Solution ◽  
Residual Stress Distribution ◽  
Hardening Effect ◽  
Reverse Yielding ◽  
Walled Cylinder ◽  
Elastic Unloading

Most of the earlier solutions for residual stresses were based on the assumption of elastic unloading and only a few considered reverse yielding. In this paper a new theoretical model for a high strength steel is proposed and a closed-form solution of residual stresses in autofrettaged tubes has been obtained. The new results indicate that the influence of the combined Bauschinger and hardening effect on the residual stress distribution is significant.

Leg kinematic analysis and prototype experiments of walking-operating multifunctional hexapod robot

2013 ◽  
Vol 228 (12) ◽  
pp. 2217-2232 ◽  
Author(s):  
Pan Yang ◽  
Feng Gao
Keyword(s):  
Kinematic Analysis ◽  
Kinematic Model ◽  
Form Solution ◽  
Spherical Joint ◽  
Universal Joint ◽  
Step Size ◽  
Work Space ◽  
Prismatic Joint ◽  
Forward Kinematic ◽  
Close Form

This paper presents kinematic analysis of a 3-degree of freedom parallel mechanism for hexapod walking-operating multifuctional robot. Each leg of the robot consists of three limbs: universal joint – prismatic joint chain (1-UP) and universal joint – prismatic joint – spherical joint chain (2-UPS) and at the end of the leg there is passive spherical joint to adjust to the uneven ground. In this paper, first the forward kinematic model is built and it shows that the model has close-form solution. Then the work space is discussed in which the robot feet trajectories can be projected. It can be shown that the current trajectories of the feet only take very small work space. After that force analysis is performed and the results show that the payload capability of the mechanism is very high. Experiments of the prototype show that the robot can walk easily with more than 150 kg loads while the step size is more than 0.5 m.

Sign in / Sign up

Export Citation Format

Share Document