Finite Element Modeling and Mechanical Evaluation of Anteversion in Femur and Femoral Prosthesis

2000 ◽  
Author(s):  
Nader Arafati ◽  
Jean Yves Lazennec ◽  
Roger Ohayon ◽  
Gérard Saillant
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Hip Prosthesis ◽  
Femoral Shaft ◽  
Vertical Axis ◽  
Geometrical Model ◽  
Shear Stresses ◽  
Cement Interface ◽  
Element Modeling ◽  
Von Mises

Abstract We studied the mechanical effects of anteversion of hip prosthesis, using a geometrical model of the femoral bone derived from computed tomography sections. Linear elastic mechanical behavior was assumed for both cortical and trabecular bone. The results of finite element modeling were studied qualitatively. Stress distribution was evaluated during one-legged stance loading of models with various degrees of anteversion. The undeniable impact of anteversion raises questions about the interpretation of bone remodeling. Anteversion modifies mechanical stresses, most notably those through the femoral shaft; they are rotated around the vertical axis in the same direction as the anteversion. Changes in Von Mises stresses were larger than changes in longitudinal stresses, suggesting that anteversion may have a more significant impact on shear stresses, which may cause failure at the prosthesis-cement interface, particularly toward the middle of the femoral shaft.

PERSONALIZED FINITE ELEMENT MODELING ANALYSIS OF FEMUR BONE HEALING AFTER INTRAMEDULLARY NAILING

2016 ◽  
Vol 16 (05) ◽  
pp. 1650061 ◽  
Author(s):  
JIANGJUN ZHOU ◽  
RUI YI ◽  
MIN ZHAO ◽  
DA LIU ◽  
RENFA LV ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Intramedullary Nailing ◽  
Bone Healing ◽  
Fracture Site ◽  
Von Mises Stress ◽  
Element Modeling ◽  
Modeling Analysis ◽  
Von Mises ◽  
Healing Group

Purpose: Based on rapid modeling 1 year after intramedullary nailing, personalized finite element modeling analysis was performed to predict whether the broken ends of fractured bones would break again after nail dislodgement. Methods: A total of 10 male volunteers with femur fractures who had undergone intramedullary nailing were selected 1 year after fixation and were divided into healing ([Formula: see text][Formula: see text]5) and non-healing ([Formula: see text][Formula: see text]5) groups based on X-ray analysis. We modeled each femoral fracture and performed finite element analyses after the intramedullary nail was dislodged. Static loads and constraints were applied to each model to simulate a person standing on one leg. Results: In the healing group, the von Mises stress concentrations and stress concentration point distribution were located outside the bone healing area, indicating that the stress was not concentrated at the fracture site. In the non-healing group, the maximum von Mises stress for various materials was located in the broken ends of the fractured bone, indicating that the stress was concentrated at the fracture site. Conclusion: Personalized modeling can be used to analyze bone healing before removal of a fixator to predict the stability of the fractured bone after fixator removal and to rapidly decide whether slow walking could refracture the broken ends.

scholarly journals Cost-Effective Bulk Glass Reinforced Composite Columns

2020 ◽  
Vol 4 (2) ◽  
pp. 47
Author(s):  
John Cotter ◽  
Rasim Guldiken
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Low Cost ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Shear Stresses ◽  
Bulk Glass ◽  
Element Modeling ◽  
Reinforced Composite ◽  
Structural Applications

The cost of construction has been increasing, stemming mostly from increased material costs. One potential method to address this issue is the introduction of novel composites for use in structural applications. Bulk glass may prove to be a superior compositing material due to its low cost and high strength. The introduction of bulk soda-lime glass to structural applications is nontrivial; due to glass’ unique properties, such as its relatively low Young’s modulus (when compared to steel) and brittleness, compositing glass has proven difficult. A novel concept of a glass-reinforced composite column (GRCC) is introduced that works to benefit from glass’ unique properties for structural applications. The results indicate that GRCCs can be designed that have costs that are estimated to be 11% less than typical timber construction members. Additionally, GRCCs are estimated to provide a 50% cost advantage over similarly strong structural steel sections. By interpreting the results of finite element modeling, which was conducted iteratively to form buckling load to cost curves, three regions were identified that occur as the glass percentage is increased. These regions also exist with columns made of other materials (such as steel). Additionally, the finite element modeling (FEM)-determined shear stresses have smaller values than the shear strengths of typical sizing agents. In conclusion, GRCCs provide significant cost advantages (up to 50% cost reduction) over steel, and slight cost advantages when compared to structural timbers, although GRCCs have the added benefit of consisting of non-degrading materials.

Exact First Order Finite Element Modeling for Eddy Current NDE

1991 ◽  
Vol 3 (1) ◽  
pp. 235-253 ◽  
Author(s):  
L. D. Philipp ◽  
Q. H. Nguyen ◽  
D. D. Derkacht ◽  
D. J. Lynch ◽  
A. Mahmood
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Eddy Current ◽  
Element Modeling ◽  
First Order ◽  
Eddy Current Nde

Tire Vibration Modes and Effects on Vehicle Ride Quality

1993 ◽  
Vol 21 (1) ◽  
pp. 23-39 ◽  
Author(s):  
R. W. Scavuzzo ◽  
T. R. Richards ◽  
L. T. Charek
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Operating Conditions ◽  
Modal Testing ◽  
Ride Quality ◽  
Vibration Modes ◽  
Inflation Pressure ◽  
Passenger Cars ◽  
Element Modeling ◽  
Road Surfaces

Abstract Tire vibration modes are known to play a key role in vehicle ride, for applications ranging from passenger cars to earthmover equipment. Inputs to the tire such as discrete impacts (harshness), rough road surfaces, tire nonuniformities, and tread patterns can potentially excite tire vibration modes. Many parameters affect the frequency of tire vibration modes: tire size, tire construction, inflation pressure, and operating conditions such as speed, load, and temperature. This paper discusses the influence of these parameters on tire vibration modes and describes how these tire modes influence vehicle ride quality. Results from both finite element modeling and modal testing are discussed.

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