Influence of Acetabular Liner Design on Periprosthetic Pressures during Daily Activities

2014 ◽  
Vol 601 ◽  
pp. 159-162
Author(s):  
Mircea Krepelka ◽  
Mirela Toth-Taşcău
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Pressure ◽  
Design Parameters ◽  
Acetabular Liner ◽  
Hip Prostheses ◽  
Small Influence ◽  
The Difference ◽  
Contact Pressures ◽  
Element Method

In this study, periacetabular pressures produced by different acetabular liner geometries were analyzed using Finite Element Method. The cup models consist of hemispherical metal shells fitted with normal and different chamfered polyethylene liner geometries, with the same degree of femoral head coverage. The aim of this study was to understand the influence of the design parameters of the chamfered liners, which are primarily designed to increase the range of motion (ROM) of the hip joint and reduce the risk of impingement, on the acetabular contact pressures. The cup models were loaded to simulate periacetabular pressures during routine activities. The proposed models have been analyzed considering a cup position of 40olateral abduction and 15oanteversion. The results show that the difference in contact pressure between the normal and chamfer models was not substantial in the given orientation of the cup. Also, the increase of the chamfer angle has a small influence on the maximum contact pressures, although that could be also dependent on the reduction of the polyethylene thickness. Pre-clinical testing of total hip prostheses using Finite Element Method enables the evaluation of contact pressures and stress distribution, and proves to be a valuable tool to analyze the parameters reducing the contact pressure.

Deformations and Stresses in Face-Hobbed Spiral Bevel Gears

2011 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Nodal Point ◽  
Design Parameters ◽  
Element Discretization ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Tooth Surfaces ◽  
Spiral Bevel ◽  
Element Method

In this study an attempt is made to predict displacements and stresses in face-hobbed spiral bevel gears by using the finite element method. A displacement type finite element method is applied with curved, 20-node isoparametric elements. A method is developed for the automatic finite element discretization of the pinion and the gear. The full theory of the generation of tooth surfaces of face-hobbed spiral bevel gears is applied to determine the nodal point coordinates on tooth surfaces. The boundary conditions for the pinion and the gear are set automatically as well. A computer program was developed to implement the formulation provided above. By using this program the influence of design parameters and load position on tooth deflections and fillet stresses is investigated. On the basis of the results, obtained by performing a big number of computer runs, by using regression analysis and interpolation functions, equations for the calculation of tooth deflections and fillet stresses are derived.

scholarly journals The Search of Spatial Functions of Pressure in Adjustable Hydrostaticradial Bearing

2015 ◽  
Vol 9 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Dmytro Fedorynenko ◽  
Sergiy Boyko ◽  
Serhii Sapon
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Deformation ◽  
Tangential Direction ◽  
The Finite Element Method ◽  
Radial Bearing ◽  
Operational Characteristics ◽  
Service Conditions ◽  
The Difference ◽  
Element Method

Abstract The analysis of spatial functions of pressure considering the geometrical deviations and the elastic deformation of conjugate surace have been considered. The analysis of spatial functions of pressure is performed by the finite element method. The difference of the size of pressure in a tangential direction of a pocket of a support under various service conditions has been investigated. A recommendation for improving of operational characteristics in regulated hydrostatic radial bearing has been developed.

Effect of Traffic Flow on Characteristics of Piezoelectric Harvesting Unit

2014 ◽  
Vol 672-674 ◽  
pp. 902-905 ◽  
Author(s):  
Chun Hua Sun ◽  
Guang Qing Shang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Power ◽  
Traffic Flow ◽  
Contact Pressure ◽  
Green Energy ◽  
The Finite Element Method ◽  
Oil Resources ◽  
Element Method

To protect dwindling coal and oil resources and open up a new way of renewable green energy, the technology of piezoelectric harvesting from pavement is proposed. Effect of traffic flow, including contact pressure and speed of a vehicle, on characteristics of a piezoelectric harvesting unit is discussed with the finite element method. Results show that the harvested electric power is approximately linear with the contact pressure and a vehicle’s speed. The contact pressure takes more effect on the harvested electric power and stress on pavement than the vehicle’s speed. A PHU of 280*280*20mm can harvest about 10mJ electric power when the contact pressure is 0.85MPa. That shows that application of the piezoelectric harvesting unit has very nice optimistic prospects.

Stability Analysis for Coupling Hydraulic-Mechanical Unsaturated Deposit Body under Rainfall Infiltration

2013 ◽  
Vol 838-841 ◽  
pp. 768-772
Author(s):  
Qiang Ren
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Safety Factor ◽  
Unsaturated Flow ◽  
Flow Behavior ◽  
Flow Theory ◽  
Rainfall Infiltration ◽  
Strongly Coupled ◽  
The Difference ◽  
Element Method

In view of the deficiency of traditional saturated soil theory analyzing seepage and stability of slope under rainfall infiltration, based on the saturated-unsaturated flow theory, considering the mechanical behavior of slope which strongly coupled with flow behavior, the hydraulic-mechanical coupled finite element method on the case of rainfall induced instability in deposit body in Front of gushui Dam are used. The safety factor is calculated based on stress field obtained from the finite element method, with modified unsaturated Mohr-Coulomb failure criterion. The influences of rainfall duration and rainfall intensity to stability of deposit body are analyzed; the difference between calculated safety factor based on unsaturated flow theory and saturated flow theory is discussed.

Structural Deformation and Stress Analysis of Aircraft Wing by Finite Element Method

2014 ◽  
Vol 906 ◽  
pp. 318-322 ◽  
Author(s):  
M. Fazlay Rabbey ◽  
Anik Mahmood Rumi ◽  
Farhan Hasan Nuri ◽  
Hafez M. Monerujjaman ◽  
M. Mehedi Hassan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Properties ◽  
Structural Deformation ◽  
Design Parameters ◽  
Design Phase ◽  
Aircraft Wing ◽  
Detail Design ◽  
The Cost ◽  
Element Method

Wing of an aircraft is lift producing component. It makes aircraft airborne by generating lift>weight. The wing must take the full aircraft weight during flying. So, it is very sophisticated task for designing a wing by keeping consideration of every design parameters simultaneously. This paper contains analysis of structural properties of wing by using finite element method. For well-organized design all the variables must be considered from the beginning of the design phase. The design phases for aircraft are: conceptual, preliminary and detail design. Until the preliminary design phase the aircraft structure is not considered. During these phases the material of the wing should be selected in such a way so that it can perform efficiently with less unexpected phenomena (drag) for which responsible properties are displacement, stress etc. Currently the most focusing area for the aero-elastic investigation is to design wing with good aerodynamic shape which will associated with less dragging structural behavior. It helps to reduce SFC (Specific Fuel Consumption) and so the cost. The analysis on that has done through Computational means as well as simulation technique to develop knowledge about the variation of aircraft wing structural properties.

Robust Optimization for Tube Bending Process Based on Finite Element Method

2012 ◽  
Vol 531-532 ◽  
pp. 746-750
Author(s):  
Xue Wen Chen ◽  
Ze Hu Liu ◽  
Jing Li Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Robust Design ◽  
Process Parameters ◽  
Design Method ◽  
Design Parameters ◽  
Tube Bending ◽  
Performance Variation ◽  
Bending Process ◽  
Element Method

The main causes of performance variation in tube bending process are variations in the mechanical properties of material, initial tube thickness, coefficient of friction and other forming process parameters. In order to control this performance variation and to optimize the tube bending process parameters, a robust design method is proposed in this paper for the tube bending process, based on the finite element method and the Taguchi method. During the robust design process, the finite element analysis is incorporated to simulate the tube bending process and calculate the objective function value, the orthogonal design method is selected to arrange the simulation experiments and calculate the S/N ratio. Finally, a case study for the tube bending process is implemented. With the objective to control tube crack (reduce the maximum thinning ratio) and its variation, the robust design mathematical model is established. The optimal design parameters are obtained and the maximum thinning ratio has been reduced and its variation has been controlled.

scholarly journals PENGARUH POLA PADA SISTEM CAM MENGGUNAKAN METODE ELEMEN HINGGA

2019 ◽  
Vol 2 (2) ◽  
pp. 59
Author(s):  
Nur Muhammad Ariseno ◽  
Afri Medika Utama ◽  
Bambang Setiawan ◽  
Noegroho Djarwanti
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Construction Costs ◽  
Modification System ◽  
Maintenance Costs ◽  
Road Pavement ◽  
The Difference ◽  
Soft Subgrade ◽  
Cam Systems ◽  
Element Method

<em>Cakar Ayam Modification System (CAM) has been widely used as one of the solutions to road pavement problems in soft subgrade, although construction costs were initially high, the total costs incurred were smaller due to small maintenance costs. This research analyzes the deflection produced in a triangle patterned CAM system and quadrilateral with variations in the distance between claws of 2.25 m. Loading uses truck loads based on SNI 1725 2016 with three different position variations each in the middle and edge of the pavement. The analysis was carried out using Finite Element Method-based software which has been proven to be able to approach the original conditions in the field. The results of the analysis show that the CAM pattern with triangular pattern is better at reducing deflection that occurs compared to quadrilateral CAM systems. The deflection difference produced by the triangular CAM system against the clawless pavement system reached 36.97% while on the quadrilateral CAM system the difference was only 28.56%.</em>

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