scholarly journals Hole in One: an element reduction approach to modeling bone porosity in finite element analysis

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8112
Author(s):  
Beatriz L. Santaella ◽  
Z. Jack Tseng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Material Properties ◽  
Major Influence ◽  
Mathematical Approach ◽  
Element Analysis ◽  
Physical Element ◽  
Physical Changes ◽  
Reduction Approach

Finite element analysis has been an increasingly widely applied biomechanical modeling method in many different science and engineering fields over the last decade. In the biological sciences, there are many examples of FEA in areas such as paleontology and functional morphology. Despite this common use, the modeling of trabecular bone remains a key issue because their highly complex and porous geometries are difficult to replicate in the solid mesh format required for many simulations. A common practice is to assign uniform model material properties to whole or portions of models that represent trabecular bone. In this study we aimed to demonstrate that a physical, element reduction approach constitutes a valid protocol for addressing this problem in addition to the wholesale mathematical approach. We tested a customized script for element reduction modeling on five exemplar trabecular geometry models of carnivoran temporomandibular joints, and compared stress and strain energy results of both physical and mathematical trabecular modeling to models incorporating actual trabecular geometry. Simulation results indicate that that the physical, element reduction approach generally outperformed the mathematical approach: physical changes in the internal structure of experimental cylindrical models had a major influence on the recorded stress values throughout the model, and more closely approximates values obtained in models containing actual trabecular geometry than solid models with modified trabecular material properties. In models with both physical and mathematical adjustments for bone porosity, the physical changes exhibit more weight than material properties changes in approximating values of control models. Therefore, we conclude that maintaining or mimicking the internal porosity of a trabecular structure is a more effective method of approximating trabecular bone behavior in finite element models than modifying material properties.

scholarly journals Hole in One: an element reduction approach to modeling bone porosity in finite element analysis

2019 ◽  
Author(s):  
Beatriz L Santaella ◽  
Z. Jack Tseng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Material Properties ◽  
Model Material ◽  
Major Influence ◽  
Mathematical Approach ◽  
Element Analysis ◽  
Physical Element ◽  
Reduction Approach

Finite element analysis has been an increasingly widely used tool in many different science and engineering fields over the last decade. In the biological sciences, there are many examples of its use in areas as paleontology and functional morphology. Despite this common use, the modeling of porous structures such as trabecular bone remains a key issue because of the difficulty of meshing such highly complex geometries during the modeling process. A common practice is to mathematically adjust the boundary conditions (i.e. model material properties) of whole or portions of models that represent trabecular bone. In this study we aimed to demonstrate that a physical, element reduction approach constitutes a valid protocol to this problem in addition to the mathematical approach. We tested a new element reduction modeling script on five exemplar trabecular geometry models of carnivoran temporomandibular joints, and compared stress results of both physical and mathematical approaches to trabecular modeling to models incorporating actual trabecular geometry. Simulation results indicate that that the physical, element reduction approach generally outperformed the mathematical approach. Physical changes in the internal structure of experimental cylindrical models had a major influence on the recorded stress values throughout the model, and more closely approximates values obtained in models containing actual trabecular geometry than solid models with modified trabecular material properties. Therefore, we conclude that for modeling trabecular bone in finite element simulations, maintaining or mimicking the internal porosity of a trabecular structure is recommended as a fast and effective method in place of, or alongside, modification of material property parameters to better approximate trabecular bone behavior observed in models containing actual trabecular geometry.

scholarly journals Hole in One: an element reduction approach to modeling bone porosity in finite element analysis

2019 ◽  
Author(s):  
Beatriz L Santaella ◽  
Z. Jack Tseng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Material Properties ◽  
Model Material ◽  
Major Influence ◽  
Mathematical Approach ◽  
Element Analysis ◽  
Physical Element ◽  
Reduction Approach

Finite element analysis has been an increasingly widely used tool in many different science and engineering fields over the last decade. In the biological sciences, there are many examples of its use in areas as paleontology and functional morphology. Despite this common use, the modeling of porous structures such as trabecular bone remains a key issue because of the difficulty of meshing such highly complex geometries during the modeling process. A common practice is to mathematically adjust the boundary conditions (i.e. model material properties) of whole or portions of models that represent trabecular bone. In this study we aimed to demonstrate that a physical, element reduction approach constitutes a valid protocol to this problem in addition to the mathematical approach. We tested a new element reduction modeling script on five exemplar trabecular geometry models of carnivoran temporomandibular joints, and compared stress results of both physical and mathematical approaches to trabecular modeling to models incorporating actual trabecular geometry. Simulation results indicate that that the physical, element reduction approach generally outperformed the mathematical approach. Physical changes in the internal structure of experimental cylindrical models had a major influence on the recorded stress values throughout the model, and more closely approximates values obtained in models containing actual trabecular geometry than solid models with modified trabecular material properties. Therefore, we conclude that for modeling trabecular bone in finite element simulations, maintaining or mimicking the internal porosity of a trabecular structure is recommended as a fast and effective method in place of, or alongside, modification of material property parameters to better approximate trabecular bone behavior observed in models containing actual trabecular geometry.

MICRO-FINITE ELEMENT ANALYSIS OF TRABECULAR BONE YIELD BEHAVIOR — EFFECTS OF TISSUE NONLINEAR MATERIAL PROPERTIES

2011 ◽  
Vol 11 (03) ◽  
pp. 563-580 ◽  
Author(s):  
HE GONG ◽  
MING ZHANG ◽  
YUBO FAN
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Bone Tissue ◽  
Material Properties ◽  
Material Nonlinearity ◽  
Nonlinear Material ◽  
Yield Strain ◽  
Element Analysis ◽  
Tissue Material

Bone tissue material nonlinearity and large deformations within the trabecular network are important for the characterization of failure behavior of trabecular bone at both the apparent and tissue levels. Micro-finite element analysis (μFEA) is a useful tool for determining the mechanical properties of trabecular bone due to certain experimental difficulties. The aim of this study was to determine the effects of bone tissue nonlinear material properties on the apparent- and tissue-level mechanical parameters of trabecular bone using μFEA. A bilinear tissue constitutive model was proposed to describe the bone tissue material nonlinearity. Two trabecular specimens with different micro-architectures were taken as examples. The effects of four parameters, i.e., tissue Young's modulus, tissue yield strain in tension, tissue yield strain in compression, and post-yield modulus on the apparent yield stress/strain, tissue von Mises stress distribution, the amount of tissue elements yielded in compression and tension under compressive and tensile loading conditions were obtained using nine cases for different values of those parameters by totally 36 nonlinear μFEA. These data may provide a reference for more sophisticated evaluations of bone strength and the related fracture risk.

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.

Warpage Simulation During Fan-Out Wafer-Level Packaging Process with Uncertainty of Material Properties

2021 ◽  
Vol 21 (5) ◽  
pp. 2987-2991
Author(s):  
Geumtaek Kim ◽  
Daeil Kwon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Coefficient Of Thermal Expansion ◽  
Input Output ◽  
Wafer Level ◽  
High Input ◽  
Element Analysis ◽  
Packaging Process ◽  
Wafer Level Packaging

Along with the reduction in semiconductor chip size and enhanced performance of electronic devices, high input/output density is a desired factor in the electronics industry. To satisfy the high input/output density, fan-out wafer-level packaging has attracted significant attention. While fan-out wafer-level packaging has several advantages, such as lower thickness and better thermal resistance, warpage is one of the major challenges of the fan-out wafer-level packaging process to be minimized. There have been many studies investigating the effects of material properties and package design on warpage using finite element analysis. Current warpage simulations using finite element analysis have been routinely conducted with deterministic input parameters, although the parameter values are uncertain from the manufacturing point of view. This assumption may lead to a gap between the simulation and the field results. This paper presents an uncertainty analysis of wafer warpage in fan-out wafer-level packaging by using finite element analysis. Coefficient of thermal expansion of silicon is considered as a parameter with uncertainty. The warpage and the von Mises stress are calculated and compared with and without uncertainty.

Damage Length Predictor for High-Speed Craft

1999 ◽  
Vol 36 (04) ◽  
pp. 203-210
Author(s):  
Steven P. McGee ◽  
Armin Troesch ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
High Speed ◽  
Historical Data ◽  
Element Analysis ◽  
Damage Prediction ◽  
Structural Layout ◽  
Vessel Speed ◽  
Indenter Geometry

In 1994 the International Maritime Organization adopted the Code of Safety for High-Speed Craft (HSC Code). After two years of use, several shortfalls were found, one being the damage length predictor, which is based on traditional steel, mono-hulled vessels. Other damage predictors were developed based on historical data, but they do not account for variables such as aluminum or fiberglass construction, transverse members, indenter geometry variation, or for the case where the vessel comes to rest on the grounding object. This paper proposes a damage prediction model based on material properties, structural layout, grounding object geometry, and vessel speed. The model incorporates four grounding mechanisms: plate cutting, plate tearing, crushing of plate behind transverse members, and transverse member failure. The method is used to determine the resistance energy, compared to the kinetic energy, of the vessel, to determine an effective damage length. Finite-element analysis was used to model the failure of both aluminum and steel transverse members with significant differences in the results. It was found that the transverse members provided the majority of the resistance energy in one grounding mechanism and negligible resistance energy in another.

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