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 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.

Response of Dolos Concrete Armor Units to Impact Loads

1991 ◽  
Vol 113 (4) ◽  
pp. 286-291 ◽  
Author(s):  
J. W. Tedesco ◽  
P. B. McGill ◽  
W. G. McDougal
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Concrete Strength ◽  
Impact Resistance ◽  
Nonlinear Material ◽  
Impact Loads ◽  
Model Formulation ◽  
Element Analysis ◽  
The Impact

A finite element analysis is conducted to determine the critical impact velocities for concrete dolos. The model formulation includes deformations at the contact surface and nonlinear material properties. Two dolos orientations are considered: vertical fluke seaward and horizontal fluke seaward. In both cases, the larger units fail at lower angular impact velocities. It is also shown that doubling the concrete strength increases the impact resistance by approximately 40 percent.

Finite Element Analysis of Pressurized Fabric Beams With Material Nonlinearity

2006 ◽  
Author(s):  
Hui Zhang ◽  
William G. Davids ◽  
Michael L. Peterson ◽  
Adam Turner ◽  
Christopher Malm
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Virtual Work ◽  
Material Nonlinearity ◽  
Woven Fabric ◽  
Nonlinear Material ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Bend Tests ◽  
Point Bend

This paper presents a finite element analysis of inflated fabric beams that considers nonlinear material response and shear deformations. Applying the principle of virtual work, we obtain the FEM formulation for inflated fabric beams with material nonlinearity. Comparisons between 4-point bend tests of inflated woven fabric beams and finite element results indicate that the finite element analysis provides good estimates of deflections, and that it is important to incorporate the effects of shear deformation and pressure when predicting inflated fabric beam response.

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 A Nonlinear Finite-Element Analysis Tool to Prevent Rupture of Power Transformer Tank

2021 ◽  
Vol 13 (3) ◽  
pp. 1048
Author(s):  
Samuel Brodeur ◽  
Van Ngan Lê ◽  
Henri Champliaud
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Pressure Rise ◽  
Nonlinear Finite Element Analysis ◽  
High Energy ◽  
Nonlinear Finite Element ◽  
Nonlinear Material ◽  
Stress Strain ◽  
Element Analysis

High-energy internal failures of transformers are catastrophic events which are hardly predictable. For this reason, a full-scale controlled experiment represents a valuable learning opportunity to gather accurate information about sequence of events during the very short time in which the failure occurs. Controlled parameters include tank design, material properties, experimental load and measurements. In this paper, we present a detailed investigation using nonlinear finite-element analysis of a 210-MVA transformer high-pressure experiment. We begin by evaluating the relationship between internal arcing pressure rise and tank expansion characteristics. Since this relationship is not linear due to geometric and material nonlinearities, an iterative process is proposed to ensure result accuracy. Stress–strain material properties are retrieved by tension experiments of specimens extracted from the tested tank to enable accurate comparison of numerical and experimental results. It is shown in this paper that nonlinear material parameters have a small influence on the tank pressure rise, but a significant one on large strain prediction and therefore the true stress-strain curve is recommended. In addition, the ductile rupture criterion based on the ultimate plastic strain of the material correlates with the experimental and explicit dynamic analysis results. This can ensure a certain design margin for tank rupture prevention.

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