scholarly journals Fabrication of Low-Cost Hip Implant using Direct Metal Laser Sintering Technique

2019 ◽  
Vol 8 (4) ◽  
pp. 4544-4547
Keyword(s):  
Finite Element ◽  
Low Cost ◽  
Fibrous Tissue ◽  
Three Dimensional ◽  
Stress Shielding ◽  
Element Analysis ◽  
Hip Implant ◽  
Neck Shaft Angle ◽  
Hip Morphology ◽  
Direct Laser

Total hip replacement (THR) is the most popular surgery been performed in orthopedic surgery due to the inclination of musculoskeletal disorder and the aging population worldwide. However, the implant’s cost-burdened the patient, especially in the ASEAN region. The main objective of this study was to fabricate the low-cost hip implant using direct laser metal sintering (DMLS). The framework starts with the three dimensional of hip anthropometric datasets from computed tomography scanner, followed with the design of hip implant, computational analysis using finite element, and finally fabrication using DMLS technique. The morphological results demonstrated the value of neck-shaft angle was 130.46º, and the femoral head offset of 30.35 mm. The finite element analysis showed strain distribution was 65 MPa for the implant in metaphyseal region and 110 MPa for intact femur under staircase physiological loading which indicated inhibition of stress shielding at medical calcar region, and micromotion was 4.8 µm which prevent the formation of fibrous tissue and promoting osseointegration between implant-bone interfaces. This study proposed the fabrication using the DMLS technique, which produced accurate implant with low-cost, which suits the ASEAN hip morphology that prolongs implant lifetime.

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

ACETABULAR LOAD-TRANSFER AND MECHANICAL STABILITY: A FINITE ELEMENT ANALYSIS COMPARING DIFFERENT CEMENTLESS SOCKETS

2014 ◽  
Vol 14 (05) ◽  
pp. 1450063 ◽  
Author(s):  
D. F. M. PAKVIS ◽  
D. JANSSEN ◽  
B. W. SCHREURS ◽  
N. VERDONSCHOT
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Stress Shielding ◽  
Physiological Strain ◽  
Element Analysis ◽  
Strain Pattern ◽  
Component Interface

Acetabular stress shielding may be a failure mechanism of acetabular constructs promoting osteolysis, aseptic loosening and failure. We used three-dimensional finite element analysis (FEA) to evaluate the effect of flexible sockets on acetabular stress shielding. The sockets were made of (1) full polyethylene (PE), (2) PE with a metal bearing and (3) a PE insert with a metal backing was used as a traditional stiff implant. We compared the strain energy density and interfacial micro-motions between bone and cementless sockets during walking. In our FEA model, the most elastic socket (case 1) showed the highest levels of micro-motion during walking (400 μm). The most rigid socket (case 3) showed smaller areas of high micro-motions. Assuming a threshold for ingrowth of 50 microns, the flexible cup showed an ingrowth area of almost 40%, whereas the other two cases showed stable areas covering 60% of the total bone–component interface. Furthermore, we found that the introduction of an implant generates a very different strain pattern directly around the implant as compared with the intact case, which has a horse-shoe shaped cartilage layer in the acetabulum. This difference was not affected much by the stiffness of the implant; a more flexible implant resulted in only slightly higher strain levels. Bone strains over 1.5 mm from the cup showed physiological values and were not affected by the stiffness of the implant. Hence, this study shows that the physiological strain patterns are not obtained in the direct periprosthetic bone, regardless of the stiffness of the material.

Mechanics of the canine femur with two types of hip replacement stems

2003 ◽  
Vol 16 (03) ◽  
pp. 145-52 ◽  
Author(s):  
L. Banks-Sills ◽  
R. Eliasy ◽  
R. Shahar
Keyword(s):  
Finite Element ◽  
Hip Replacement ◽  
Three Dimensional ◽  
Stress Shielding ◽  
Femoral Stem ◽  
Cementless Stem ◽  
Entire Cross Section ◽  
Element Analysis ◽  
Periprosthetic Bone Loss ◽  
Intact Femur

SummaryThe long-term performance of total hip replacement is of concern to veterinary surgeons. Two of the main complications associated with this procedure are implant loosening and stress shielding. Designs of the femoral stem which will avoid loosening and achieve maximum endurance while reducing stress shielding and periprosthetic bone loss are sought.In the intact femur the stress is distributed over the entire cross section of the bone. After hip replacement this pattern of stress distribution is altered because of the manner in which the load is transferred from the prosthesis to the bone.The objective of this study was to examine the stresses that develop in the femur and implant components of two different methods of hip replacement used clinically in dogs. Anatomic, three-dimensional finite element models of the canine femur with a cemented femoral stem and a Zurich cementless stem were constructed. The stresses and displacements were calculated by the finite element analysis method, under physiologic loads that included muscle forces and joint reaction forces. The results were compared to results obtained by a similar analysis of an intact femur.This study demonstrates that the Zurich cementless method causes less stress shielding in the proximal femoral cortex than does the cemented method. Implant stresses are higher in the Zurich cementless stem, but still within an acceptable range.

Semi-Automated Hexahedral Mesh Generation of Human Vertebrae by Isoparametric Mapping

2008 ◽  
Author(s):  
Yifei Dai ◽  
Glen L. Niebur
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Spinal Instrumentation ◽  
Stress Shielding ◽  
Finite Element Models ◽  
Hexahedral Mesh ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
As Stress ◽  
Three Dimensional Finite Element

Subject-specific finite element models provide a means to explore inter-subject biomechanical variations, and have been widely used in the study of spinal fusion such as stress-shielding due to spinal instrumentation [1], and to assess biomechanical response to aging and disease [2–4]. Three-dimensional finite element models of vertebrae are usually constructed from CT scans. However, manual generation of meshes is labor intensive. As such, techniques that simplify creation of meshes are needed to make finite element analysis more feasible for large biomechanical studies and clinical applications.

Finite Element Analysis in Femoral Fixation with TA3 Titanium Compressioll Plate

2013 ◽  
Vol 647 ◽  
pp. 16-19 ◽  
Author(s):  
Gang Tang ◽  
Shi Lei Liu ◽  
Dong Mei Wang ◽  
Gao Feng Wei ◽  
Cheng Tao Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometric Model ◽  
Three Dimensional ◽  
Stress Shielding ◽  
Shielding Effect ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Femoral Fixation ◽  
Element Method

To analyze the stress shielding in femoral fixation with TA3 Titanium compressioll plate by using the finite element method. Firstly, establish TA3 Titanium compressioll plate, screws and three-dimensional geometric model of the femur; and its mesh, and the establishment of the corresponding three-dimensional finite element model; the final definition of material properties, and load boundary conditions. During standing state, the strength of plate and screw has been analyzed by the finite element method, while the femoral stress shielding has been analyzed. Standing stress when compared to normal bone stock, TA3 Titanium compressioll plate and screws for femoral stress shielding effect is not obvious. Established in this paper plate on the femur stress shielding of the analytical method can be widely applied in other state analysis of stress shielding bone fracture.

scholarly journals Application of the finite element method to the design of an ankle orthosis

2021 ◽  
Vol 2130 (1) ◽  
pp. 012013
Author(s):  
D Stefańczak ◽  
J Gajewski ◽  
M Rogala
Keyword(s):  
Finite Element ◽  
Low Cost ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Body Part ◽  
The Body ◽  
Design Stage ◽  
Mechanical Resistance ◽  
Three Dimensional Model ◽  
Element Analysis

Abstract AFO (Ankle-Foot Orthosis), which covers the ankle and foot, protects and supports the ankle joint as well as the structures around it. It contributes to the maintenance of the correct gait cycle. Owing to orthoses, the functional capacity of the body part is significantly improved, and so is the quality of life for the user. Personalized orthoses, which are adapted to the anatomy of the user, are more and more often produced by the additive methods. The use of 3D printing for the manufacturing medical devices is becoming increasingly common due to the low cost of the whole process, short production time and the possibility of the product personalization. One of the stages in manufacturing AFOs with the additive method is to create a three-dimensional model of the orthosis in CAD software. Finite element analysis was performed to assess the mechanical properties of the orthosis. The influence of geometry and the materials used were investigated with FEM analysis software. As a result of structural analysis during the design stage, the assessment of the medical device in terms of its durability and mechanical resistance without putting the user at risk is possible. On the basis of the obtained results, the structure strength was compared.

scholarly journals Finite Element Analysis of Structural Concrete Insulated Panels Subjected to Dynamic Loadings

2020 ◽  
Vol 1 (2) ◽  
pp. 31-37
Author(s):  
Anwar Khitab
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Low Cost ◽  
Three Dimensional ◽  
Insulation Material ◽  
Structural Concrete ◽  
Dead Weight ◽  
Element Analysis ◽  
Building Systems ◽  
Three Dimensional Finite Element

Human population is growing around the world day by day, necessitating highly sustainable and energy efficient building systems. In conventional building systems, significant amount of energy is consumed for providing thermal comfort to the occupants. Materials used for thermal insulation not only increase the cost of the buildings but also increase the dead weight. Structural concrete insulated panel system (SCIP) provide thermally efficient, light weight, and low-cost solution as compared to the conventional systems. SCIP system is new innovation in which, insulation material is placed between two layers of concrete. Due to low weight, it can be easily handled and transported to project sites. In present research, the performance of SCIP walls in a typical school double story building is examined by three-dimensional finite element analysis, using SAP2000. The response is evaluated by varying the thickness of the insulation layer in terms of safety and serviceability. The results show that the buildings incorporating SCIPs are capable to withstand high dynamic and earthquake loads and are significantly economical as compared to the conventional building systems.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

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