scholarly journals A Three-Dimensional Inverse Finite Element Analysis of the Heel Pad

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Snehal Chokhandre ◽  
Jason P. Halloran ◽  
Antonie J. van den Bogert ◽  
Ahmet Erdemir
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Element Analysis ◽  
Heel Pad ◽  
Tool Force ◽  
Specific Material ◽  
Inverse Finite Element Analysis

Quantification of plantar tissue behavior of the heel pad is essential in developing computational models for predictive analysis of preventive treatment options such as footwear for patients with diabetes. Simulation based studies in the past have generally adopted heel pad properties from the literature, in return using heel-specific geometry with material properties of a different heel. In exceptional cases, patient-specific material characterization was performed with simplified two-dimensional models, without further evaluation of a heel-specific response under different loading conditions. The aim of this study was to conduct an inverse finite element analysis of the heel in order to calculate heel-specific material properties in situ. Multidimensional experimental data available from a previous cadaver study by Erdemir et al. (“An Elaborate Data Set Characterizing the Mechanical Response of the Foot,” ASME J. Biomech. Eng., 131(9), pp. 094502) was used for model development, optimization, and evaluation of material properties. A specimen-specific three-dimensional finite element representation was developed. Heel pad material properties were determined using inverse finite element analysis by fitting the model behavior to the experimental data. Compression dominant loading, applied using a spherical indenter, was used for optimization of the material properties. The optimized material properties were evaluated through simulations representative of a combined loading scenario (compression and anterior-posterior shear) with a spherical indenter and also of a compression dominant loading applied using an elevated platform. Optimized heel pad material coefficients were 0.001084 MPa (μ), 9.780 (α) (with an effective Poisson’s ratio (ν) of 0.475), for a first-order nearly incompressible Ogden material model. The model predicted structural response of the heel pad was in good agreement for both the optimization (<1.05% maximum tool force, 0.9% maximum tool displacement) and validation cases (6.5% maximum tool force, 15% maximum tool displacement). The inverse analysis successfully predicted the material properties for the given specimen-specific heel pad using the experimental data for the specimen. The modeling framework and results can be used for accurate predictions of the three-dimensional interaction of the heel pad with its surroundings.

scholarly journals Estimating the material properties of heel pad sub-layers using inverse Finite Element Analysis

2017 ◽  
Vol 40 ◽  
pp. 11-19 ◽  
Author(s):  
Nafiseh Ahanchian ◽  
Christopher J. Nester ◽  
David Howard ◽  
Lei Ren ◽  
Daniel Parker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Element Analysis ◽  
Heel Pad ◽  
Inverse Finite Element Analysis

scholarly journals On the Design of a Biodegradable POC-HA Polymeric Cardiovascular Stent

2012 ◽  
Author(s):  
Joonas Ponkala ◽  
Mohsin Rizwan ◽  
Panos S. Shiakolas
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Polymeric Composite ◽  
Coronary Stent ◽  
Element Analysis ◽  
Material Models ◽  
Solid Models ◽  
Biodegradable Stents

The current state of the art in coronary stent technology, tubular structures used to keep the lumen open, is mainly populated by metallic stents coated with certain drugs to increase biocompatibility, even though experimental biodegradable stents have appeared in the horizon. Biodegradable polymeric stent design necessitates accurate characterization of time dependent polymer material properties and mechanical behavior for analysis and optimization. This manuscript presents the process for evaluating material properties for biodegradable biocompatible polymeric composite poly(diol citrate) hydroxyapatite (POC-HA), approaches for identifying material models and three dimensional solid models for finite element analysis and fabrication of a stent. The developed material models were utilized in a nonlinear finite element analysis to evaluate the suitability of the POC-HA material for coronary stent application. In addition, the advantages of using femtosecond laser machining to fabricate the POC-HA stent are discussed showing a machined stent. The methodology presented with additional steps can be applied in the development of a biocompatible and biodegradable polymeric stents.

Three-dimensional finite element analysis of effects of roller intervals on tool forces and wall thickness in stagger spinning of thin-walled tube

2012 ◽  
Vol 227 (7) ◽  
pp. 1429-1440 ◽  
Author(s):  
Yong Li ◽  
Jin Wang ◽  
Guo-Dong Lu ◽  
Qi-Song Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wall Thickness ◽  
Three Dimensional ◽  
Element Analysis ◽  
Shape Accuracy ◽  
Tool Force ◽  
Spinning Process ◽  
Force Components ◽  
Three Dimensional Finite Element

Roller intervals are the key parameters of the stagger spinning process, which affect the shape accuracy and productivity of the products. In this article, the effects of different roller intervals in axial and radial directions on tool forces, wall thickness, and strain and stress variations in stagger spinning have been analyzed numerically by the finite element analysis. The results show that with the increasing of the axial roller intervals, the differences between tool force components (axial, radial, and tangential) become lower at first, and then have the trend to be higher. The similar phenomenon on tool force occurs when the radial interval of roller 3 increases and that of roller 2 decreases. Wall thickness variations are mainly affected by axial roller intervals; the bigger the axial intervals are, the higher the variations of wall thickness that would be seen. Meanwhile, the real reductions of wall thickness are mainly affected by radial roller intervals. When the radial interval of roller 3 is larger than that of roller 2, there would be a higher real wall thickness reduction.

QUANTIFICATION OF IN VIVO MITRAL VALVE MATERIAL PROPERTIES USING INVERSE FINITE ELEMENT ANALYSIS

2008 ◽  
Vol 41 ◽  
pp. S119
Author(s):  
Gaurav Krishnamurthy ◽  
Daniel B. Ennis ◽  
Akinobu Itoh ◽  
Wolfgang Bothe ◽  
Julia Swanson ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mitral Valve ◽  
Material Properties ◽  
Element Analysis ◽  
Inverse Finite Element Analysis

Finite element analysis and dentistry

2015 ◽  
Vol 6 (3) ◽  
pp. 134-139
Author(s):  
Douglas Hammond ◽  
Justin Whitty
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Product Design ◽  
Material Properties ◽  
Manufacturing Process ◽  
New Products ◽  
Element Analysis ◽  
Specific Material

Finite element analysis (FEA) uses a computerised model to enable a material or model to be artificially stressed or analysed for specific material properties. FEA has been used in industry but is now being used more frequently in medicine and dentistry. It enables the design of new products and also allows for product refinement. This process makes it possible to verify a proposed design prior to what may be an expensive manufacturing process. It may also be able to determine why an existing product design has failed.

Quantification of In Vivo Stresses in the Ovine Anterior Mitral Valve Leaflet

2008 ◽  
Author(s):  
Gaurav Krishnamurthy ◽  
Akinobu Itoh ◽  
Wolfgang Bothe ◽  
Daniel B. Ennis ◽  
Julia C. Swanson ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mitral Valve ◽  
Material Properties ◽  
Element Analysis ◽  
Mitral Valve Leaflet ◽  
Mitral Valves ◽  
Mitral Repair ◽  
Inverse Finite Element Analysis

Mitral valve (MV) disease affects millions worldwide. An important goal of present-day heart valve research is to create bioengineered tissue valves to replace diseased mitral valves, if it is judged that mitral repair will not be durable. The design of such valves will pivot on understanding the stresses acting in the native MV leaflets to design a bioprosthesis which will withstand these stresses. In order to quantify such stresses in vivo, we utilized radiopaque marker technology and performed an “inverse” finite element analysis of the resulting 4-D data to determine the material properties of the anterior MV leaflet in the beating ovine heart. We then used these material properties in a “forward” finite element analysis to estimate the stresses in the native anterior MV leaflet.

Role of Material Properties in the Finite Element Solution for Three-Dimensional Composites—A Sensitivity Study

1995 ◽  
Vol 209 (2) ◽  
pp. 157-160
Author(s):  
H-B Hellweg ◽  
M A Crisfield
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Sensitivity Study ◽  
Two Dimensional ◽  
Element Analysis ◽  
The Impact

Three-dimensional material test data for orthotropic laminae are difficult to obtain. Consequently, various simplifications are made for the material properties of individual layers in a finite element analysis, ranging from the assumption of transversely isotropic layers to applying two-dimensional material data in a three-dimensional analysis. In order to investigate the impact and validity of such simplifications, the sensitivity of the stresses and deformations in a finite element analysis on the material properties was investigated.

Sign in / Sign up

Export Citation Format

Share Document