Validación fisiológica de un modelo de pie humano para estudio de patología de dedo en garra

2021 ◽  
Author(s):  
◽  
L. M. González Torres
Keyword(s):  
Finite Element ◽  
Soft Tissues ◽  
Surgical Techniques ◽  
Lower Extremities ◽  
Structural Behavior ◽  
Finite Element Models ◽  
Claw Toe ◽  
Different Types ◽  
Numerical Finite Element ◽  
Future Work

The standing finite element models allow the study of their biomechanical-structural behavior. Research of this type provides podiatrists with knowledge in improving surgical techniques, thus allowing the exploration of new alternatives in the correction of biomechanical alterations in the lower extremities. Thus, reporting models in the literature with different types of contact in the joints, insertion of soft tissues such as the skin, as well as variation in the properties of the tissues. This research presents two numerical finite element models, healthy foot and claw toe pathology in the second radius. Based on the model of Mancera et al. (2020). The modifications include changes in load and contour conditions to simulate the "midstance" phase with 700 N load. The pathology model presents rotations and adjustments in the main soft tissues involved in the second radius of the foot. The two models were meshed and solved under the same conditions. The results of the simulation of the models are validated with the Costa Bartani and Kite angle. This was performed in the unloaded and loaded foot cases to verify that the model is within the parameters of the healthy foot. The Costa Bartani angle presented the greatest variation, while the Kite angle remained within the range value for a healthy foot. The models proposed during their evaluation show that pathologies that only involve the second radius of the foot affect the aforementioned angles, therefore, the biomechanical-structural behavior of the foot, allowing the study of other pathologies in future work.

Experimental study on anti-collision device using titanium steel and recycle tires

2021 ◽  
Author(s):  
Ziheng Xin ◽  
Haiying Ma ◽  
Junjie Wang ◽  
Hao Gao ◽  
Yanchen Song
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Test Specimen ◽  
Impact Load ◽  
Finite Element Models ◽  
Strong Impact ◽  
New Device ◽  
Different Types ◽  
Scale Test ◽  
Ship Collision

<p><br clear="none"/></p><p>Anti-collision devices can reduce the damage of bridge columns under ship collision, and a new device is proposed in the paper using a combination of titanium steel and recycle tires. The proposed device effectively improves the performance of buffering energy dissipation and durability under strong impact load. A 0.6 scale test specimen was designed and tested to investigate the behavior of the device under impact load; finite element models were conducted to analyze and compare with the experimental results. The performances of different types of the anti-collision device are compared, and the failure mechanism is studied.</p>

Cemented Wellbore Experiments Reveals That Cement Interface Debonding Modeling Overestimate Potential Leakage Rates

2020 ◽  
Author(s):  
Zachary Speer ◽  
Jarrett Wise ◽  
Runar Nygaard ◽  
Geir Hareland ◽  
Eric Ford ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Models ◽  
Interface Debonding ◽  
Finite Element Models ◽  
Wellbore Integrity ◽  
Cement Interface ◽  
Abandoned Wells ◽  
Numerical Finite Element ◽  
Physical And Chemical

Abstract Leakage pathways may develop in wellbores during construction, production, or during and after plug and abandonment (P&A). These pathways are created due to events and conditions during cementing operations, or because of physical and chemical changes after cementing such as changes in temperature and wellbore pressures, and deterioration of the cement. Common leakage pathways develop inside the cement sheath, or as microannuli along the cement-tubing interface. Numerous evidence exists showing that wellbores leak, but there is no verified method to determine if a well will leak or not. To ensure long term wellbore integrity, leakage risks need to be evaluated for plugged and abandoned wells. To evaluate leakage risks from plugged and abandoned wells, numerical finite element models have been developed and used to investigate leakage scenarios during the life of the well. Currently, little work has been done to verify finite element numerical models with experimental data regarding flowpath size in cement sheaths. The aim of this paper is to model previously published experimental data to determine if the finite element models can accurately predict leakage potentials. Two lengths of cemented annuli were modeled, each with conventional and expanding cement to replicate the Aas et. al. [1] experiments. The numerical results show that the simulated microannuli overestimate flow rate compared to experimental data, indicating that flow path dimensions and/or fluid friction factor does not accurately represent the fluid flow in the experiments.

Coupled Porohyperelastic Mass Transport (PHEXPT) Finite Element Models for Soft Tissues Using ABAQUS

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Jonathan P. Vande Geest ◽  
B. R. Simon ◽  
Paul H. Rigby ◽  
Tyler P. Newberg
Keyword(s):  
Finite Element ◽  
Mass Transport ◽  
Soft Tissues ◽  
Convective Transport ◽  
Finite Deformations ◽  
Nonlinear Material ◽  
Finite Element Models ◽  
Finite Element Software ◽  
Mobile Species ◽  
Highly Nonlinear

Finite element models (FEMs) including characteristic large deformations in highly nonlinear materials (hyperelasticity and coupled diffusive/convective transport of neutral mobile species) will allow quantitative study of in vivo tissues. Such FEMs will provide basic understanding of normal and pathological tissue responses and lead to optimization of local drug delivery strategies. We present a coupled porohyperelastic mass transport (PHEXPT) finite element approach developed using a commercially available ABAQUS finite element software. The PHEXPT transient simulations are based on sequential solution of the porohyperelastic (PHE) and mass transport (XPT) problems where an Eulerian PHE FEM is coupled to a Lagrangian XPT FEM using a custom-written FORTRAN program. The PHEXPT theoretical background is derived in the context of porous media transport theory and extended to ABAQUS finite element formulations. The essential assumptions needed in order to use ABAQUS are clearly identified in the derivation. Representative benchmark finite element simulations are provided along with analytical solutions (when appropriate). These simulations demonstrate the differences in transient and steady state responses including finite deformations, total stress, fluid pressure, relative fluid, and mobile species flux. A detailed description of important model considerations (e.g., material property functions and jump discontinuities at material interfaces) is also presented in the context of finite deformations. The ABAQUS-based PHEXPT approach enables the use of the available ABAQUS capabilities (interactive FEM mesh generation, finite element libraries, nonlinear material laws, pre- and postprocessing, etc.). PHEXPT FEMs can be used to simulate the transport of a relatively large neutral species (negligible osmotic fluid flux) in highly deformable hydrated soft tissues and tissue-engineered materials.

Extended “LMPHETS” Finite Element Models for Coupled Mechano-Electro-Chemical Transport in Soft Tissues

2002 ◽  
Author(s):  
B. R. Simon ◽  
G. A. Radtke ◽  
P. H. Rigby ◽  
S. K. Williams ◽  
Z. P. Liu
Keyword(s):  
Finite Element ◽  
Soft Tissues ◽  
Electrical Potential ◽  
Fluid Pressure ◽  
Nonlinear Material ◽  
Solid Matrix ◽  
Test Problems ◽  
Finite Element Models ◽  
Material Interfaces ◽  
Mobile Species

Soft tissues are hydrated fibrous materials that exhibit nonlinear material response and undergo finite straining during in vivo loading. A continuum model of these structures (“LMPHETS” [1,2]) is a porous solid matrix (with charges fixed to the solid fibers) saturated by a mobile fluid (water) and multiple species (e.g., three mobile species designated by α, β = p, m, b where p = +, m = −, and b = ± charge) dissolved in the mobile fluid. A “mixed” LMPHETS theory and finite element models (FEMs) were presented [1] in which the “primary fields” are the displacements, ui = xi − Xi and the mechano-electro-chemical potentials, ν˜ξ* (ξ, η = f, e, m, b) that are continuous across material interfaces. “Secondary fields” (discontinuous at material boundaries) are mechanical fluid pressure, pf; electrical potential, μ˜e; and concentration or “molarity”, cα = dnα / dVf. Here an extended version of these models is described and numerical results are presented for representative test problems associated with transport in soft tissues.

scholarly journals The peripheral soft tissues should not be ignored in the finite element models of the human knee joint

2017 ◽  
Vol 56 (7) ◽  
pp. 1189-1199 ◽  
Author(s):  
Hamid Naghibi Beidokhti ◽  
Dennis Janssen ◽  
Sebastiaan van de Groes ◽  
Nico Verdonschot
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Soft Tissues ◽  
Finite Element Models ◽  
Human Knee ◽  
Human Knee Joint

Incorporation of medical image data in finite element models to track strain in soft tissues

1998 ◽  
Author(s):  
Jeffrey A. Weiss ◽  
Richard D. Rabbitt ◽  
Anton E. Bowden ◽  
Bradley N. Maker
Keyword(s):  
Finite Element ◽  
Medical Image ◽  
Soft Tissues ◽  
Image Data ◽  
Finite Element Models ◽  
Medical Image Data

Tapering Effects on the Installation of Suction Caissons in Clay

2008 ◽  
Author(s):  
Mostafa Zeinoddini ◽  
Woorya H. Shariati ◽  
Mahmood Nabipour
Keyword(s):  
Finite Element ◽  
Finite Element Models ◽  
Finite Element Approach ◽  
Pull Out ◽  
Full Penetration ◽  
Element Approach ◽  
Numerical Finite Element ◽  
Wall Slope ◽  
Suction Caissons ◽  
Considerable Enhancement

This paper reports results from an investigation on the tapering effects on the installation and pull-out performance of suction caissons. A numerical finite element approach has been used for the study. The finite element models have first been calibrated/verified against several available experimental data for the installation of the upright suction caissons in clay. The verified models have then been used to examine the behaviour of the tapered suction caissons during the pull-out and installation phases. Numerical results indicate that tapered caissons present considerable enhancement in their pull-out capacity comparing to those from corresponding upright caissons. Also it has been noticed that in general tapered caissons of positive wall slopes need extra forces, in comparison to their equivalent upright caissons, to achieve a full penetration. However, at least with those models studied, these extra forces have found to be less than twenty five percent when the wall slope varies from zero (upright) to 15%. This is while the additional pull-out capacities that might be achieved from these tapered suction caissons could reach to several hundred percents. An almost linear relationship has been observed between the total installation force and the caisson’s wall slope.

Porohyperelastic-Transport Finite Element Models of the Eye Using ABAQUS

2004 ◽  
Author(s):  
P. H. Rigby ◽  
R. I. Park ◽  
B. R. Simon
Keyword(s):  
Finite Element ◽  
Anterior Chamber ◽  
Soft Tissues ◽  
Ganglion Cells ◽  
Vitreous Body ◽  
Flow Fields ◽  
Finite Element Models ◽  
Tissue Fluid ◽  
Fluid Flux ◽  
Mobile Species

Glaucoma is related to damage to nerve ganglion cells in the optic nerve head (ONH) including the lamina cribrosa, (LC). This disease is associated with elevated intraocular pressure (IOP) and possibly reduced trabecular meshwork (TM) outflow. The ABAQUS program was used to develop axisymmetric porohyperelastic (PHE) pore fluid finite element models (FEMs) to determine deformations, stresses, tissue fluid pressures (pf), and mobile fluid flux in the eye. These FEMs simulated aqueous pressure-fluid flow fields in the anterior chamber via the TM and posterior pressure-flow fields in the vitreous body (VIT) and ONH. Constant inlet flow at the ciliary processes (CP) was applied. The anterior chamber was modeled as a highly porous material containing large amounts of fluid whereas the VIT was modeled as a gel with mobile fluid. All ocular soft tissues were considered to be linear, isotropic PHE materials. Posterior transport was regulated by varying the permeability of the LC, retina, choroid, and sclera material layers. Two FEMs, i.e. IOP=15 mm Hg (normal) and IOP=44 mm Hg (glaucoma) were developed by varying the permeability of the TM. Deformations and tissue fluid pressures, fluid flux (relative fluid velocities), and stresses were determined and agree well with experimental data and other numerical model results. The displacement of the LC was 21–62 μm; the LC pressure gradient was 25–73 mm Hg/mm; and the posterior outflow ranged from 5%–15% of the inflow at the CP. The PHE material law can be extended to include nonlinear permeability effects and mobile species transport using a porohyperelastic-transport-swelling (PHETS) theory in future FEMs.

Initial imperfections and the initiation of wrinkling in finite element modelling of deep drawing

2000 ◽  
Vol 214 (1) ◽  
pp. 63-73 ◽  
Author(s):  
J Hematian ◽  
P M Wild
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
Finite Element Modelling ◽  
Annular Plate ◽  
Finite Element Models ◽  
Essential Requirement ◽  
Element Modelling ◽  
Initial Imperfections ◽  
Different Types ◽  
Out Of Plane

The effect of initial imperfections on the initiation of wrinkling in finite element models of deep drawing operations is assessed. Models of an annular plate are subjected to radial in-plane loading and the effects of different types, magnitudes and distributions of imperfections are investigated. A model of a circular plate subjected to out-of-plane loading from a punch and die is similarly investigated and the results are compared with experimental data. It is confirmed that initial imperfections are an essential requirement for the initiation of wrinkling for the case of in-plane loading. Initial imperfections are shown to be unimportant in the initiation of wrinkling for the case of out-of-plane loading.

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