scholarly journals An Investigation into a Gear-Based Knee Joint Designed for Lower Limb Prosthesis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
M. S. H. Bhuiyan ◽  
I. A. Choudhury ◽  
M. Dahari ◽  
Y. Nukman ◽  
S. Z. Dawal
Keyword(s):  
Knee Joint ◽  
Motion Analysis ◽  
Maximum Stress ◽  
Real Data ◽  
Fe Analysis ◽  
Knee Prostheses ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Lower Limb Prosthesis ◽  
Limb Prosthesis

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e−004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb.

scholarly journals Nonlinear Finite Element Analysis of the Fluted Corrugated Sheet in the Corrugated Cardboard

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiguo Zhang ◽  
Tao Qiu ◽  
Riheng Song ◽  
Yaoyu Sun
Keyword(s):  
Finite Element Analysis ◽  
Maximum Stress ◽  
Static Pressure ◽  
Nonlinear Finite Element ◽  
Drop Test ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Corrugated Board ◽  
Pressure Test ◽  
Corrugated Cardboard

The choice of corrugated medium, flute size, combining adhesive, and linerboards can be varied to design a corrugated board with specific properties. In this paper, the nonlinear finite element analysis of the fluted corrugated sheet in the corrugated cardboard based on software SolidWorks2008 was investigated. The model of corrugated board with three or more flutes is reliable for stress and displacement measurement to eliminate the influence of the number of flutes in models. According to the static pressure test, with the increase of flute heightHor arc radius of flute, the maximum stress in the models decreased and the maximum displacement increased. However the maximum stress and maximum displacement in the models increase nonlinearly in the static pressure test with the increase of the flute angleθ. According to the drop test, with the increase of flute heightH, the maximum stress of goods on the upper board in the drop test decreased. The maximum stress of the model in the drop test decreases firstly and then increases with the increase of flute angle, and the optimal flute angleθcould be 60° for corrugated board. All the conclusions are consistent with experimental data or product standards.

Visco-Anisotropic Hyperelastic Finite Element Analysis of Knee Joint Considering Deformation Induced Anisotropy Evolution of Meniscus

2017 ◽  
Author(s):  
Tsuyoshi Eguchi ◽  
Yoshihiro Tomita ◽  
Koji Yamamoto ◽  
Yusuke Morita ◽  
Eiji Nakamachi
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Knee Joint ◽  
Constitutive Equations ◽  
Collagen Fiber ◽  
Collagen Fibers ◽  
Fe Analysis ◽  
Fe Model ◽  
Element Analysis ◽  
Human Knee Joint

Recently, the observation technology of micro structure has made great progress, and then collagen fiber orientation of meniscus can be measured accurately. This makes it possible to evaluate the stress in knee joint by considering the collagen fiber orientations at the micro scale. In this study, we developed visco-isotropic/anisotropic hyperelastic constitutive equations (Iso-VHE/Aniso-VHE) for menisci, which can reflect the initial collagen fiber orientations and their deformation induced rotations. Subsequently, we constructed a finite element (FE) model of normal human knee joint by using the magnetic resonance (MR) tomography images. The FE analysis with the proposed constitutive equations and FE model clarifies the reinforcement effect of collagen fibers on mechanical characteristics of knee joint. Our computational prediction clarified that the stress concentration occurred on the contact parts of articular cartilages of femur and tibia, which met the tendency of the experimental results. Furthermore, the maximum compressive stresses evaluated by Aniso-VHE always showed a lower value as compared with Iso-VHE. This suggested that the anisotropy of meniscal collagen fibers relieved the stress concentration and lowered the maximum value. Therefore, our proposed FE analysis was proved to have a potential to reveal the functions of meniscus and knee joint.

Finite Element Analysis and Optimal Design for Mold Shelf of Powder Molding Press

2010 ◽  
Vol 34-35 ◽  
pp. 1559-1562
Author(s):  
Jun Liu ◽  
Xiao Zhou ◽  
Gang Yi Zhou ◽  
Xin Long Dong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Load Distribution ◽  
Maximum Stress ◽  
Ansys Software ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Load Component ◽  
Main Support

Mold shelf of powder molding press(PMP) is the main load component. Control the deformation of mold shelf is a key problem. In this paper, based on the basic theory of finite element analysis(FEA), the constraints and load conditions of main support parts of mold shelf were simulated and analyzed . ANSYS software optimized the structure of mold shelf. Top width of the stress part increased to 15mm, its height from 80mm down to 50mm. The results showed that the maximum displacement of mold shelf reduced to 0.4740mm, the maximum stress reduced 843.44MPa to 742.38MPa. Load distribution of the mold is more uniform, deformation and displacement also improved. It provides a new method and theoretical basis for optimal design of powder molding shelf.

Synthesis Optimization of Planar Mechanisms

2009 ◽  
Vol 15 ◽  
pp. 55-60 ◽  
Author(s):  
E. Lugo-González ◽  
E.A. Merchán-Cruz ◽  
Luis Héctor Hernández-Gómez
Keyword(s):  
Genetic Algorithms ◽  
Knee Joint ◽  
Objective Function ◽  
Lower Limb ◽  
Dimensional Synthesis ◽  
Planar Mechanisms ◽  
Lower Limb Prosthesis ◽  
Study Case ◽  
Mathematical Relationships ◽  
Limb Prosthesis

This work presents an approach based on Genetic Algorithms (GA) for the dimensional synthesis of planar mechanisms as path generators. The study case deals with the development of a four-bar mechanism with application to lower limb prosthesis, specifically the knee joint. The optimization algorithm contains the objective function defined by the synthesis problem and the representation of a set of mathematical relationships that describe the kinematic restrictions of the planar mechanism. The objective function is a given numerical value for every solution that corresponds to the best possible mechanism. In other words, this objective function is the determinant to minimize the error between the desired and the generated points and can be affected by the lengths of the links, the transmission angles, the Grashof conditions, type of mechanisms, etc. The population, crossover or mutation in the GA determines the exactitude in the results. The first goal of this work is to find the optimal dimensions of the links to minimize the error between the actual coupler curve and the desired path.

Influences of Varus Tilt on the Stresses in Human Prosthetic Knee Joint

2016 ◽  
Vol 823 ◽  
pp. 143-148 ◽  
Author(s):  
Dan Calafeteanu ◽  
Daniela Tarniţă ◽  
Marius Catana ◽  
Dan Tarnita
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Knee Joint ◽  
Knee Prostheses ◽  
Element Analysis ◽  
Human Knee ◽  
Prosthetic Knee ◽  
Ansys Simulation ◽  
Human Knee Joint ◽  
Total Knee

In this paper the effects of varus tilt on contact stresses in the three components of total knee prostheses using 3D finite element analysis were investigated. Using Ansys simulation environment, six complex virtual models of human knee joint–prosthesis assembly obtained for six different varus tilts which increase from 176o to 191o, with an increment of 3o have been subjected to finite element analysis in order to obtain the stress maps and total displacements maps.

STRUCTURAL STRESS ANALYSIS ON THE RUBBER DIAPHRAGM OF AIR-OPERATED VALVE

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4565-4570 ◽  
Author(s):  
YOUNG-SHIN LEE ◽  
TAIK-DONG CHO ◽  
SUNG-HO KO ◽  
HYUN-SEUNG LEE ◽  
SUNG-KY SHIN
Keyword(s):  
Stress Analysis ◽  
Maximum Stress ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Thickness Change ◽  
Damage Rate ◽  
Section Area ◽  
Edge Part ◽  
Edge Side ◽  
Spring Support

Air-operated valves are used extensively in the power-generation industry for process control and system isolation functions. A study on the prevention of damage of an air operated valve is very important. Specially, diaphragm in an actuator of an air-operated valve has the highest damage rate. In this study, the stress of diaphragm with thickness change is analyzed. For this analysis, four experiments were conducted to obtain material properties of rubber. A stress analysis is carried out by commercial FEM code, ANSYS 8.0. It is compared with tension test to verify finite element analysis. From the result of analysis, the maximum stress happened at flange edge part, and the maximum displacement happened between flange edge and spring support. This study also finds out effect of the thickness about variable thickness. Even if a section area is same, the maximum stress is varied with the thickness of edge side.

scholarly journals AN APPROACH FOR QUANTITATIVE EVALUATION OF TRANSFEMORAL PROSTHESIS SOCKET BY FINITE ELEMENT ANALYSIS

2019 ◽  
pp. 182-185
Author(s):  
LE VAN TUAN ◽  
AKIHIKO HANAFUSA ◽  
SHINICHIROU YAMAMOTO
Keyword(s):  
Finite Element ◽  
Residual Limb ◽  
Interface Pressure ◽  
Element Analysis ◽  
Experimental Procedure ◽  
Experiment Method ◽  
Lower Limb Prosthesis ◽  
Transfemoral Prosthesis ◽  
Critical Process ◽  
Limb Prosthesis

Objective: The correct shaping of the socket for appropriate load distribution is a critical process in the design of lower limb prosthesis sockets.Several studies have been conducted to disclose these parameters; they can be divided into two methods: Experiment method and computationmethod. The finite element (FE) analysis has highly effective for study the interface pressure between the residual limb and socket. However, there isa little study focus on creating separate models of the socket and residual limb. Almost research using the same shape of socket and residual limb orusing the unreal model of the socket. This study will be given some solutions for the above issues.Methods: The author creates two models of the residual limb: Same and different with the shape of the socket. After that, the FE models weregenerated with appropriate conditions of the donning process. The experimental procedure was conducted for comparison and discussion with theresults of the simulation.Results: The results in case of different shape of socket and residual limb suggest that it is the better model for evaluating the interface pressure.Conclusions: The procedure developed through this work can be used by future researchers and prosthesis designers in understanding how to betterdesign the socket and transfemoral prostheses.

Finite Element Analysis of Failure in Cu Interconnect Megasonic Cleaning

2013 ◽  
Vol 562-565 ◽  
pp. 1471-1476 ◽  
Author(s):  
Ya Ting Huang ◽  
Chun Ling Meng ◽  
Nian Peng Wu ◽  
Xiu Ping Dong ◽  
Xin Chun Lu
Keyword(s):  
Finite Element ◽  
Line Width ◽  
Maximum Stress ◽  
Structural Deformation ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Megasonic Cleaning ◽  
Cu Interconnect ◽  
Bubble Collision ◽  
Low K

Megasonic cleaning has been one of the most successful techniques for Cu/low-k interconnects post-CMP cleaning. The structural deformation and stress of Cu and low-k materials in megasonic cleaning are examined with finite element method (FEM). The maximum stress is concentrated in the binding area between Cu and low-k. With decrease of Cu line width, the maximum stress increases and the max value exceeds the yield strength of Cu which results in the plastic deformation. The increasing frequency will change the bubble collision times. Therefore the fatigue is potential. The maximum displacement moves from center to the sides of top surface with increase of line width. When the line width is 25nm, the deformation is the largest.

Optimization of Translational Flexure Joints Using Corrugated Units Under Stress Constraints

2021 ◽  
pp. 1-12
Author(s):  
Canran Li ◽  
Nianfeng Wang ◽  
Fan Yue ◽  
Xianmin Zhang
Keyword(s):  
Natural Frequency ◽  
Stiffness Matrix ◽  
Maximum Stress ◽  
Stress Constraints ◽  
Axial Stiffness ◽  
Stiffness Ratio ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Different Types ◽  
Flexure Joints

Abstract When optimizing 2-DOF corrugated flexure stages, most approaches for calculating the maximum stress on the corrugated flexure (CF) beam depend on finite element analysis (FEA). The current paper introduces the design optimization for stages using CF units under stress constraints. The stress state is solved; then, based on that, the maximum displacement under stress constraints is deduced. The natural frequency formula of the micropositioning stage is further derived from the results of the stiffness matrix. The stage configurations corresponding to the maximum displacement are optimized by restricting the off-axis/axial stiffness ratio and natural frequency of the stage. The optimal results of different types are validated by FEA and experiments.

Finite Element Analysis of Assembly Body of Conical Pick

2013 ◽  
Vol 397-400 ◽  
pp. 573-576
Author(s):  
Xin Zheng Pu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Maximum Stress ◽  
Rock Cutting ◽  
The Finite Element Method ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Conical Pick ◽  
Mechanics Performance

In order to improve the structure mechanics performance of assembly body of conical pick, the finite element method was taken to analyse assembly body of conical pick based on rock cutting theory, and the distortion law of stress and displacement of carbide tip, pick arbor and pick holder were obtained. The results show that the maximum stress appearing in pick carbide tip and its weld site is 371MPa, maximum stress of pick holder appearing in its weld site is 157MPa. Consequently, the quality of the weld should be ensured in processing and manufacturing or welding installation to reduce the performance of carbide tip and pick holder drop. The maximum displacement of assembly body of conical pick is 1.14mm, which has little influence on the structure mechanics performance of assembly body. The research results could provide some guidance for designing, manufacturing or welding the assembly body of conical pick.

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