scholarly journals Stress distribution in the knee joint in relation to tibiofemoral angle using the finite element method

2019 ◽  
Vol 252 ◽  
pp. 07007 ◽  
Author(s):  
Robert Karpiński ◽  
Łukasz Jaworski ◽  
Józef Jonak ◽  
Przemysław Krakowski
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Articular Cartilage ◽  
Knee Joint ◽  
Cartilage Tissue ◽  
The Finite Element Method ◽  
Human Knee ◽  
Tibiofemoral Angle ◽  
Element Method

The article presents the results of a preliminary study on the structural analysis of the knee joint, considering changes in the mechanical properties of the articular cartilage of the joint. Studies have been made due to the need to determine the tension distribution occurring in the cartilage of the human knee. This distribution could be the starting point for designing custom made human knee prosthesis. Basic anatomy, biomechanical analysis of the knee joint and articular cartilage was introduced. Based on a series of computed tomography [CT] scans, the 3D model of human knee joint was reverse-engineered, processed and exported to CAD software. The static mechanical analysis of the knee joint model was conducted using the finite element method [FEM], in three different values of tibiofemoral angle and with varying mechanical properties of the cartilage tissue. Main conclusions of the study are: the capability to absorb loads by articular cartilage of the knee joint is preliminary determined as decreasing with increasing degenerations of the cartilage and with age of a patient. Without further information on changes of cartilage’s mechanical parameters in time it is hard to determine the nature of relation between mentioned capability and these parameters.

scholarly journals Specific solution of problem of water filtering in the rocks by the finite element method

2019 ◽  
Vol 109 ◽  
pp. 00093 ◽  
Author(s):  
Olena Slashchova ◽  
Ihor Slashchov ◽  
Iryna Sapunova
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
The Finite Element Method ◽  
Water Saturated ◽  
Element Method

The article is devoted to development of methods for geofiltration calculations with taking into account peculiarities of changes of the rock physical and mechanical properties at water saturation. Methods: mathematical modeling of geomechanical and filtration processes with the help of finite element method and laboratory and underground studies. A mathematical model was formulated for solving a problem of elasticity theory by the finite element method, which took into account peculiarities of water-saturated rocks. Pattern of stress-strain state changing in the fractured water-saturated rocks under the action of critical loads, which occurred around the preparatory roadways during their operation, were established. In order to solve the filtration problems, a bank of collected initial data on physical and mechanical properties of water-saturated rocks was processed with the help of variation coefficients, which were taken into account by the method, which assumed calculation of the model loading with critical parameters.

scholarly journals Some Novel Numerical Applications of Cosserat Continua

2018 ◽  
Vol 15 (06) ◽  
pp. 1850054 ◽  
Author(s):  
Nicholas Fantuzzi ◽  
Lorenzo Leonetti ◽  
Patrizia Trovalusci ◽  
Francesco Tornabene
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Size Effects ◽  
Heterogeneous Materials ◽  
Numerical Implementation ◽  
The Finite Element Method ◽  
Strong Formulation ◽  
Cosserat Continua ◽  
Element Method

Cosserat continua demonstrated to have peculiar mechanical properties, with respect to classic Cauchy continua, because they are able to more accurately describe heterogeneous materials, as particle composites and masonry-like material, taking into account size effects. Many studies have been devoted to their numerical implementation. In this paper, some reference benchmarks, referred to an isotropic heterogeneous sample, are shown by comparing the solutions provided by strong and weak formulations. The strong formulation finite element method (SFEM), implemented in MATLAB®, is compared to the finite element method (FEM), given by COMSOL® Multiphysics, and the advantages of the two approaches are highlighted and discussed.

Compressive Strength Prediction of Quad-Diametral Lattice Structures

2020 ◽  
Vol 847 ◽  
pp. 69-74
Author(s):  
Karel Raz ◽  
Zdenek Chval ◽  
Frantisek Sedlacek
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Plastic Material ◽  
Lattice Structures ◽  
The Finite Element Method ◽  
Compressive Test ◽  
Unit Cells ◽  
Special Space ◽  
Element Method

Additive manufacturing is rapidly developing technology in all areas of industry. It is reducing the delivering time of each prototype from the manufacturer to the final user. This paper deals with mechanical properties of lattice structures. They are produced by additive technologies from the plastic material. Lattice structures are special space-filling unit cells, which can fill gaps in parts. They have good ratio between overall weight and strength. Nowadays are these structures commonly used, but their mechanical properties are not well described. This makes the design process difficult. Mechanical compressive test and virtual evaluation by the finite element method was performed. It was done for three different Quad-Diametral structures (Quad-Diametral, Quad-Diametral-Line and Quad-Diametral-Cross). Results from both testing approaches (real measurement and finite element method) are deeply described in this paper. It was shown, that the Quad-Diametral-Cross lattice cell has higher mechanical properties comparing to others. Increasing of the stiffness was 121% only with weight higher by 43%. The plastic material Ultimaker PLA (polyactic acid) was used as reference material in this research.

scholarly journals Modelling of Nanoindentation of TiAlN and TiN Thin Film Coatings for Automotive Bearing

2019 ◽  
Vol 8 (3) ◽  
pp. 7194-7199
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Yield Strength ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
The Finite Element Method ◽  
Element Method

Bearings are critical components for the transmission of motion in machines. Automotive components, especially bearings, will wear out over a certain period of time because they are constantly subjected to high levels of stress and friction. Studies have proven that coatings can extend the lifespan of bearings. Hence, it is necessary to conduct studies on coatings for bearings, particularly the mechanical and wear properties of the coating material. This detailed study focused on the mechanical properties of single-coatings of TiN and TiAIN using the finite element method (FEM). The mechanical properties that can be obtained from nano-indentation experiments are confined to just the Young’s modulus and hardness. Therefore, nanoindentation simulations were conducted together with the finite element method to obtain more comprehensive mechanical properties such as the yield strength and Poisson’s ratio. In addition, various coating materials could be examined by means of these nanoindentation simulations, as well the effects of those parameters that could not be controlled experimentally, such as the geometry of the indenter and the bonding between the coating and the substrate. The simulations were carried out using the ANSYS Mechanical APDL software. The mechanical properties such as the Young’s modulus, yield strength, Poisson’s ratio and tangent modulus were 370 GPa, 19 GPa, 0.21 and 10 GPa, respectively for the TiAlN coating and 460 GPa, 14 GPa, 0.25 and 8 GPa, respectively for the TiN coating. The difference between the mechanical properties obtained from the simulations and experiments was less than 5 %.

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