Are subject-specific models necessary to predict patellar tendon fatigue life? A finite element modelling study

Abstract The article deals with wheel-rail contact analysis at railway turnout using a finite element modelling approach. The focus is understanding the wheel-rail contact problems and finding the means of reducing these problems at railway turnouts. The main aim of the work reported in this article is to analyse fatigue life and simulate the wheel-rail contact problems for a repeated wheel loading cycle by considering the effect of normal and tangential contact force impact under different vehicle loading conditions. The study investigates the impact of tangential contact force generated due to different-angled shapes of the turnout and aims to reveal how it affects the life of contacting surfaces. The obtained results show that the maximum von-Mises equivalent alternating stress, maximal fatigue sensitivity, and maximum hysteresis loop stresses were observed under tangential contact force. These maximum stresses and hysteresis loops are responsible for rolling contact fatigue damage, and excessive deformation of the wheel-rail contact surface. At a constant rotational velocity, the tangential contact force has a significant impact on the fatigue life cycle and wheel-rail material subjected to fatigue damage at lower cycles compared to the normal contact force. The finite element modelling analysis result indicated that the contact damages and structural integrity of the wheel-rail contact surface are highly dependent on contact force type and can be affected by the track geometry parameters.

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The mechanical influence of bone spicules in the osteochondral junction: A finite element modelling study

Biomechanics and Modeling in Mechanobiology ◽

10.1007/s10237-021-01510-z ◽

2021 ◽

Author(s):

M. Arjmandi ◽

P. A. Kelly ◽

A. Thambyah

Keyword(s):

Finite Element ◽

Finite Element Modelling ◽

Element Modelling ◽

Mechanical Influence ◽

Modelling Study

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Subject specific finite element modelling of periprosthetic femoral fractures in different load cases

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2021.105059 ◽

2021 ◽

pp. 105059

Author(s):

N.S. Hennicke ◽

M. Saemann ◽

D. Kluess ◽

R. Bader ◽

M. Sander

Keyword(s):

Finite Element ◽

Finite Element Modelling ◽

Femoral Fractures ◽

Element Modelling ◽

Periprosthetic Femoral Fractures ◽

Subject Specific

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Finite-element modelling of mechanobiological factors influencing sesamoid tissue morphology in the patellar tendon of an ostrich

Royal Society Open Science ◽

10.1098/rsos.170133 ◽

2017 ◽

Vol 4 (6) ◽

pp. 170133 ◽

Cited By ~ 4

Author(s):

Kyle P. Chadwick ◽

Sandra J. Shefelbine ◽

Andrew A. Pitsillides ◽

John R. Hutchinson

Keyword(s):

Finite Element ◽

Patellar Tendon ◽

Finite Element Modelling ◽

Compressive Strain ◽

Three Dimensional ◽

Tissue Differentiation ◽

Mechanical Stimuli ◽

Element Modelling ◽

Multiple Regions ◽

Three Dimensional Models

The appearance and shape of sesamoid bones within a tendon or ligament wrapping around a joint are understood to be influenced by both genetic and epigenetic factors. Ostriches ( Struthio camelus ) possess two sesamoid patellae (kneecaps), one of which (the distal patella) is unique to their lineage, making them a good model for investigating sesamoid tissue development and evolution. Here we used finite-element modelling to test the hypothesis that specific mechanical cues in the ostrich patellar tendon favour the formation of multiple patellae. Using three-dimensional models that allow application of loading conditions in which all muscles, or only distal or only proximal muscles to be activated, we found that there were multiple regions within the tendon where transformation from soft tissue to fibrocartilage was favourable and therefore a potential for multiple patellae based solely upon mechanical stimuli. While more studies are needed to better understand universal mechanobiological principles as well as full developmental processes, our findings suggest that a tissue differentiation algorithm using shear strain and compressive strain as inputs may be a roughly effective predictor of the tissue differentiation required for sesamoid development.

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