Influence of Knee Ligament Structure Viscoelasticity on Dynamic Tests

2014 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Eduardo Granados ◽  
Ricardo Gomez
Keyword(s):  
Viscoelastic Properties ◽  
Dynamic Testing ◽  
Viscoelastic Model ◽  
Vertical Position ◽  
Dynamic Tests ◽  
Dimensional Model ◽  
Harmonic Force ◽  
Knee Ligament ◽  
Human Knee ◽  
Ligamentous Structure

This paper deals with nonlinear dynamics of viscoelastic ligament model human knee. A two dimensional model of the human knee to include tibia and femur, and the ligamentous structure between the two bones is used to investigate the influence of ligamentous viscoelastic properties on dynamic testing of human knee. An exercise in which the femur is pinned at the hip in a sitting position, and tibia in a vertical position is actuated by a vertical harmonic force at various frequencies is proposed. The viscoelastic model of ligaments shows for the knee dynamic testing a resonance in the range of 15 Hz to 20 Hz.

Dynamic Test for Human Knee Ligament Structure Assessment

2014 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Eduardo Granados
Keyword(s):  
Viscoelastic Properties ◽  
Dynamic Testing ◽  
Viscoelastic Model ◽  
Dynamic Test ◽  
Vertical Position ◽  
Dynamics Model ◽  
Harmonic Force ◽  
Knee Ligament ◽  
Human Knee ◽  
Structure Assessment

In this paper a nonlinear human knee dynamics model to include viscoelastic ligaments is proposed. The knee model is two dimensional and include tibia, femur, ligamentous knee structure, and knee cartilages. The model is used to investigate the influence of ligamentous viscoelastic properties on dynamic testing of human knee. An exercise in which the femur is pinned at the hip in a sitting position, and tibia in a vertical position is actuated by a vertical harmonic force at various frequencies is proposed. The viscoelastic model of ligaments shows better predictions on the knee dynamic testing.

Nonlinear Dynamics of Ligament Deficient Knees in Proximal-Distal Tibial Oscillatory Motion

2013 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Eduardo Granados ◽  
Thania A. Martinez
Keyword(s):  
Nonlinear Dynamics ◽  
Cruciate Ligament ◽  
Vertical Position ◽  
Sitting Position ◽  
Dimensional Model ◽  
Harmonic Force ◽  
Human Knee ◽  
Significant Difference ◽  
Ligamentous Structure ◽  
Anterior Cruciate

This paper deals with nonlinear dynamics of deficient knees. A two dimensional model of the human knee to include tibia and femur, and the ligamentous structure between the two bones is used to investigate the nonlinear dynamics of the knee in order to differentiate between normal and deficient knees. An exercise in which the femur is pinned at the hip in a sitting position, and tibia in a vertical position is actuated by a vertical soft harmonic force at various frequencies is proposed. A significant difference between the behavior of normal knees and Anterior Cruciate Ligament (ACL), and Posterior Cruciate Ligament (PCL) deficient knees is predicted.

Frequency Response of Ligament Deficient Knees in Anterior-Posterior Drawer Test

2013 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Thania A. Martinez ◽  
Eduardo Granados
Keyword(s):  
Nonlinear Dynamics ◽  
Cruciate Ligament ◽  
Sitting Position ◽  
Dimensional Model ◽  
Harmonic Force ◽  
Human Knee ◽  
Significant Difference ◽  
Ligamentous Structure ◽  
Anterior Cruciate ◽  
Anterior Posterior

This paper deals with nonlinear dynamics of deficient knees. A two dimensional model of the human knee to include tibia and femur, and the ligamentous structure between the two bones has been developed. The aim of this paper is to use nonlinear dynamics to differentiate between normal and deficient knees. An exercise in which the femur is fixed in a sitting position, and tibia is actuated by an anterior-posterior soft harmonic force at various frequencies is proposed. The results clearly show a significant difference between the behavior of normal knees and Anterior Cruciate Ligament (ACL), and Posterior Cruciate Ligament (PCL) deficient knees.

scholarly journals Effect of Degradation and Osteoarthritis on the Viscoelastic Properties of Human Knee Articular Cartilage: An Experimental Study and Constitutive Modeling

Biomechanics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 225-238
Author(s):  
Hesam Khajehsaeid ◽  
Zanko Abdollahpour ◽  
Hedyeh Farahmandpour
Keyword(s):  
Articular Cartilage ◽  
Mechanical Behavior ◽  
Energy Absorption ◽  
Tissue Damage ◽  
Viscoelastic Properties ◽  
Viscoelastic Model ◽  
Absorption Capacity ◽  
Model Parameters ◽  
Human Knee ◽  
Nonlinear Viscoelastic Model

Articular cartilage, as a hydrated soft tissue which covers diarthrodial joints, has a pivotal role in the musculoskeletal system. Osteoarthritis is the most common degenerative disease that affects most individuals over the age of 55. This disease affects the elasticity, lubrication mechanism, damping function, and energy absorption capability of articular cartilage. In order to investigate the effect of osteoarthritis on the performance of articular cartilage, the mechanical behavior of human knee articular cartilage was experimentally investigated. Progressive cyclic deformation was applied beyond the physiological range to facilitate degradation of the tissue. The relaxation response of the damaged tissue was modeled by means of a fractional-order nonlinear viscoelastic model in the framework of finite deformations. It is shown that the proposed fractional model well reproduces the tissue’s mechanical behavior using a low number of parameters. Alteration of the model parameters was also investigated throughout the progression of tissue damage. This helps predict the mechanical behavior of the osteoarthritic tissue based on the level of previous damage. It is concluded that, with progression of osteoarthritis, the articular cartilage loses its viscoelastic properties such as damping and energy absorption capacity. This is also accompanied by a loss of stiffness which deteriorates more rapidly than viscosity does throughout the evolution of tissue damage. These results are thought to be significant in better understanding the degradation of articular cartilage and the progression of OA, as well as in the design of artificial articular cartilages.

Mine Impact Burial Prediction From One to Three Dimensions

2008 ◽  
Vol 62 (1) ◽  
Author(s):  
Peter C. Chu
Keyword(s):  
Three Dimensional ◽  
Time History ◽  
Three Dimensions ◽  
Vertical Position ◽  
Burial Depth ◽  
Prediction Errors ◽  
Two Dimensional ◽  
Dimensional Model ◽  
One Dimensional ◽  
Dimensional Models

The Navy’s mine impact burial prediction model creates a time history of a cylindrical or a noncylindrical mine as it falls through air, water, and sediment. The output of the model is the predicted mine trajectory in air and water columns, burial depth/orientation in sediment, as well as height, area, and volume protruding. Model inputs consist of parameters of environment, mine characteristics, and initial release. This paper reviews near three decades’ effort on model development from one to three dimensions: (1) one-dimensional models predict the vertical position of the mine’s center of mass (COM) with the assumption of constant falling angle, (2) two-dimensional models predict the COM position in the (x,z) plane and the rotation around the y-axis, and (3) three-dimensional models predict the COM position in the (x,y,z) space and the rotation around the x-, y-, and z-axes. These models are verified using the data collected from mine impact burial experiments. The one-dimensional model only solves one momentum equation (in the z-direction). It cannot predict the mine trajectory and burial depth well. The two-dimensional model restricts the mine motion in the (x,z) plane (which requires motionless for the environmental fluids) and uses incorrect drag coefficients and inaccurate sediment dynamics. The prediction errors are large in the mine trajectory and burial depth prediction (six to ten times larger than the observed depth in sand bottom of the Monterey Bay). The three-dimensional model predicts the trajectory and burial depth relatively well for cylindrical, near-cylindrical mines, and operational mines such as Manta and Rockan mines.

Three-Dimensional Dynamic Modeling of the Human Knee to Include Tibio-Femoral and Patello-Femoral Joints

2001 ◽  
Author(s):  
Dumitru Caruntu ◽  
Mohamed Samir Hefzy
Keyword(s):  
Knee Joint ◽  
Mathematical Models ◽  
Dynamic Modeling ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Human Knee ◽  
Two Dimensional Model ◽  
Rigid Contact ◽  
Locomotor Activities

Abstract Most of the anatomical mathematical models that have been developed to study the human knee are either for the tibio-femoral joint (TFJ) or patello-femoral joint (PFJ). Also, most of these models are static or quasistatic, and therefore do not predict the effects of dynamic inertial loads, which occur in many locomotor activities. The only dynamic anatomical model that includes both joints is a two-dimensional model by Tumer and Engin [1]. The model by Abdel-Rahman and Hefzy [2] is the only three dimensional dynamic model for the knee joint available in the literature; yet, it includes only the TFJ and allows only for rigid contact.

Viscoelastic properties of doxorubicin-treated HT-29 cancer cells by atomic force microscopy: the fractional Zener model as an optimal viscoelastic model for cells

2019 ◽  
Vol 19 (3) ◽  
pp. 801-813 ◽  
Author(s):  
Maricela Rodríguez-Nieto ◽  
Priscila Mendoza-Flores ◽  
David García-Ortiz ◽  
Luis M. Montes-de-Oca ◽  
Marco Mendoza-Villa ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cancer Cells ◽  
Viscoelastic Properties ◽  
Viscoelastic Model ◽  
Zener Model ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fractional Zener Model ◽  
Ht 29

Validation of a New Finite Element Model for Human Knee Ligaments for Use in High Speed Automotive Collisions

2009 ◽  
Author(s):  
Chiara Silvestri ◽  
Louis R. Peck ◽  
Kristen L. Billiar ◽  
Malcolm H. Ray
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain Rate ◽  
High Speed ◽  
Element Model ◽  
Knee Ligament ◽  
Knee Ligaments ◽  
Human Knee ◽  
Dynamic Representation ◽  
Failure Properties

A finite element model of knee human ligaments was developed and validated to predict the injury potential of occupants in high speed frontal automotive collisions. Dynamic failure properties of ligaments were modeled to facilitate the development of more realistic dynamic representation of the human lower extremities when subjected to a high strain rate. Uniaxial impulsive impact loads were applied to porcine medial collateral ligament-bone complex with strain rates up to145 s−1. From test results, the failure load was found to depend on ligament geometric parameters and on the strain rate applied. The information obtained was then integrated into a finite element model of the knee ligaments with the potential to be used also for representation of ligaments in other regions of the human body. The model was then validated against knee ligament dynamic tolerance tests found in literature. Results obtained from finite element simulations during the validation process agreed with the outcomes reported by literature findings encouraging the use of this ligament model as a powerful and innovative tool to estimate ligament human response in high speed frontal automotive collisions.

scholarly journals Influence of Selective Laser Melting Technological Parameters on the Mechanical Properties of Additively Manufactured Elements Using 316L Austenitic Steel

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1449 ◽  
Author(s):  
Janusz Kluczyński ◽  
Lucjan Śnieżek ◽  
Krzysztof Grzelak ◽  
Jacek Janiszewski ◽  
Paweł Płatek ◽  
...  
Keyword(s):  
Energy Density ◽  
Selective Laser Melting ◽  
Dynamic Testing ◽  
Positive Impact ◽  
Image Correlation ◽  
Material Strength ◽  
Compression Tests ◽  
Dynamic Tests ◽  
Technological Parameters ◽  
Laser Melting

The main aim of this study was to investigate the influence of different energy density values used for the additively manufactured elements using selective laser melting (SLM).The group of process parameters considered was selected from the first-stage parameters identified in preliminary research. Samples manufactured using three different sets of parameter values were subjected to static tensile and compression tests. The samples were also subjected to dynamic Split–Hopkinson tests. To verify the microstructural changes after the dynamic tests, microstructural analyses were conducted. Additionally, the element deformation during the tensile tests was analyzed using digital image correlation (DIC). To analyze the influence of the selected parameters and verify the layered structure of the manufactured elements, sclerometer scratch hardness tests were carried out on each sample. Based on the research results, it was possible to observe the porosity growth mechanism and its influence on the material strength (including static and dynamic tests). Parameters modifications that caused 20% lower energy density, as well as elongation of the elements during tensile testing, decreased twice, which was strictly connected with porosity growth. An increase of energy density, by almost three times, caused a significant reduction of force fluctuations differences between both tested surfaces (parallel and perpendicular to the building platform) during sclerometer hardness testing. That kind of phenomenon had been taken into account in the microstructure investigations before and after dynamic testing, where it had been spotted as a positive impact on material deformations based on fused material formation after SLM processing.

THE EFFECT OF DISPLACEMENT RATE ON VISCOELASTIC PROPERTIES OF RAT CERVIX

2016 ◽  
Vol 28 (03) ◽  
pp. 1650018 ◽  
Author(s):  
Alireza Ashofteh Yazdi ◽  
Ali Esteki ◽  
Mohammad Mehdi Dehghan ◽  
Farhad Tabatabai Ghomsheh
Keyword(s):  
Viscoelastic Properties ◽  
Viscoelastic Model ◽  
Elastic Response ◽  
Displacement Rate ◽  
Sufficient Information ◽  
Cervical Insufficiency ◽  
Load Relaxation ◽  
Pregnant Rats ◽  
Tension Tests ◽  
Relaxation Curves

Determining the viscoelastic response of cervix at different displacement rates can provide sufficient information for the normal mechanical behavior of the tissue in assessment of cervical insufficiency. The objective of this study was to investigate the effect of displacement rate on viscoelastic properties of rat cervix. Different displacement rates were employed to measure the tensile and load-relaxation properties of cervices from virgin and 16 days post-conception pregnant rats. After preconditioning, the displacement of 2[Formula: see text]mm was applied to the distal halves of five pregnant rat’s cervices and 1 millimeter to the five virgin samples circumferentially. Uniaxial tension tests were employed at the displacement rates of 0.01, 0.1 and 1 mm/s randomly and were held for 10 min while the tissues were relaxed. Tensile and load-relaxation curves were well described by a quasi-linear viscoelastic model. Statistical analysis revealed significant correlation between the change in displacement rate and the elastic response, as well as the viscous response of the virgin samples. For pregnant samples, though, the correlation was found significant between the displacement rate and the elastic response of the tissue. Virgin tissue is strongly viscoelastic. Quantitative measurements of cervical mechanical properties will lead to a more accurate assessment of cervical insufficiency and prediction of preterm birth.

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