Applied Taguchi Method for Fatigue Testing of Customized Hip Implant

2016 ◽  
Vol 39 (12) ◽  
pp. 611-618
Author(s):  
Mangesh R. Dharme ◽  
Abhaykumar M. Kuthe ◽  
Tushar R. Deshmukh
Keyword(s):  
Taguchi Method ◽  
Safety Factor ◽  
Fatigue Testing ◽  
Geometrical Parameters ◽  
Hip Implants ◽  
Safety Factors ◽  
Element Analysis ◽  
Hip Implant ◽  
Neck Shaft Angle ◽  
Minimum Number

Purpose Human activities generate stresses, which vary with time and may result in fatigue failure of the customized hip implant. This study aims to investigate fatigue testing of customized hip implants using the minimum number of experiments by the Taguchi method, for 147 patients. This study was also useful to determine the influential geometrical parameters on the fatigue safety factor of customized hip implants. Methods Horizontal offset (HO), vertical offset (VO) and neck shaft angle (NSA) of the hip joint of 147 patients were measured on computed tomography (CT) scanned images. Stress and strain of hip implants were calculated by finite element analysis and validated by in vitro experimental tests. Fatigue safety factors were calculated by Goodman, Soderberg and Gerber's fatigue theories and maximum stresses. Results Analysis of variance results show that the highest impact on fatigue safety factors was equal to 54.38% for HO, 16.33% for VO, and was equal to 29.16% for NSA with reference to Goodman, Soderberg and Gerber's fatigue theories. The hip implant shape of experiment no. 8 has the highest safety factor value compared to all other hip implants. Conclusions The results show that HO has the maximum influence on fatigue safety factors. The determination of influential geometric parameters may be useful to redesign customized hip implants in order to achieve the highest fatigue safety factor. The Taguchi method is suitable for fatigue testing of custom hip implant with a minimum number of experiments.

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.

scholarly journals STUDI PERANCANGAN PISAU PADA MESIN PENCACAH PLASTIK MENGGUNAKAN FINITE ELEMENT ANALYSIS

2021 ◽  
Vol 7 (1) ◽  
pp. 44
Author(s):  
Rizqi Ilmal Yaqin ◽  
Mega Lazuardi Umar ◽  
Sigiet Haryo Pranoto ◽  
Angger Bagus Prasetiyo ◽  
Bambang Hari Priyambodo
Keyword(s):  
Finite Element Analysis ◽  
Safety Factor ◽  
Model Simulation ◽  
Plastic Waste ◽  
Waste Processing ◽  
Safety Factors ◽  
Stress Strain ◽  
Element Analysis ◽  
A Value ◽  
Deformation Parameters

The amount of plastic waste each year will increase by 10% every year which is a problem for a country. Therefore, proper processing of plastic waste needs to be done. Before being processed into plastic waste processing, it is necessary to have a chopping process using a plastic chopping machine. The plastic chopping machine has an important component, namely the chopping knife. Before carrying out the knife manufacturing process, it is necessary to validate the design of the blade that is used with its loading. Model simulation using software is one way to quickly validate the model. This study aims to determine the effect of loading variations on stress, strain, deformation and safety factors of the model. The use of ANSYS R17.2 software is used to analyze the chopping machine knife model with a variation of 5kg / hour, 10kg / hour, 20kg / hour and 50kg / hour capacities. The result is that the stress, strain and deformation parameters have an increase in value with increasing loading variations. The greatest values of stress, strain and deformation are in the variation of 50kg / hour respectively 64.995 Pa; 336.76 and 56,358 x 10-11mm. The value of the safety factor for all variations of loading has a value of 15. The value of the safety factor means that the design of the plastic chopping knife is safe to use up to a loading of 50kg / hour

scholarly journals Finite element analysis of Ti6Al4V porous structures for low-stiff hip implant application

2021 ◽  
Vol 12 ◽  
pp. 12
Author(s):  
Porika Rakesh ◽  
Bidyut Pal
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Hip Implants ◽  
Porous Structures ◽  
Element Analysis ◽  
Hip Implant ◽  
Femur Bone ◽  
Body Center Cubic ◽  
Effective Mechanical Properties

Solid metallic hip implants have much higher stiffness than the femur bone, causing stress-shielding and subsequent implant loosening. The development of low-stiff implants using metallic porous structures has been reported in the literature. Ti6Al4V alloy is a commonly used biomaterial for hip implants. In this work, Body-Center-Cubic (BCC), Cubic, and Spherical porous structures of four different porosities (82%, 76%, 70%, and 67%) were investigated to establish the range of ideal porosities of Ti6Al4V porous structures that can match the stiffness of the femur bone. The effective mechanical properties have been determined through Finite Element Analysis (FEA) under uniaxial compressive displacement of 0.32 mm. FEA predictions were validated with the analytical calculations obtained using Gibson and Ashby method. The effective mechanical properties of 82%, 76%, 70%, and 67% porous BCC and Cubic structures were found to match the mechanical properties of cortical bone closely. They were also well comparable to the Gibson-Ashby method-based calculations. BCC and Cubic porous structures with 67–82% porosity can mimic the stiffness of the femur bone and are suitable for low-stiff hip implant applications.

Finite Element Analysis of Surface Modification of Titanium Alloy Used for Hip Implant

2021 ◽  
Vol 1016 ◽  
pp. 1544-1548
Author(s):  
Aleksandra Vulović ◽  
Fernando Gustavo Warchomicka ◽  
Nenad Filipović
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Surface Modification ◽  
Stress Distribution ◽  
Hip Implants ◽  
Element Analysis ◽  
Bone Implant ◽  
Hip Implant ◽  
Different Types

Titanium and its alloys, especially Ti-6Al-4V have found application as hip implants due to their mechanical properties, excellent biocompatibility, and corrosion resistance. The use of cementless hip implants has increased over the years as it is thought that this type is more durable compared to cemented hip implants. Cementless hip implants have a porous surface that allows the bone to grow into it and form a strong bone–implant connection. The goal of this study is the use of Finite Element Method simulations to obtain information about how different types of surface topography of a TI-6Al-4V hip implant affect the shear stress, which is used to access the bone-implant connection. Finite Element Analysis is used to analyze the stress distribution in three simple surface modifications in a hip implant under different types of loads. The optimal surface modification out of these three is obtained based on the shear stress distribution, as it is known that lower shear stress promotes bone ingrowth. In this study, we have considered the interaction between cortical bone and implant surface. Material properties and boundary conditions used for the simulations have been adapted from literature.

scholarly journals Geometrical Effects on Ultrasonic Al Bump Direct Bonding for Microsystem Integration: Simulation and Experiments

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 750
Author(s):  
Jun-Hao Lee ◽  
Pin-Kuan Li ◽  
Hai-Wen Hung ◽  
Wallace Chuang ◽  
Eckart Schellkes ◽  
...  
Keyword(s):  
Shear Strength ◽  
Joint Strength ◽  
Maximum Stress ◽  
Geometrical Parameters ◽  
Experimental Demonstration ◽  
Joint Shear Strength ◽  
Element Analysis ◽  
Ultrasonic Bonding ◽  
Simulation Results ◽  
Geometrical Effects

This study employed finite element analysis to simulate ultrasonic metal bump direct bonding. The stress distribution on bonding interfaces in metal bump arrays made of Al, Cu, and Ni/Pd/Au was simulated by adjusting geometrical parameters of the bumps, including the shape, size, and height; the bonding was performed with ultrasonic vibration with a frequency of 35 kHz under a force of 200 N, temperature of 200 °C, and duration of 5 s. The simulation results revealed that the maximum stress of square bumps was greater than that of round bumps. The maximum stress of little square bumps was at least 15% greater than those of little round bumps and big round bumps. An experimental demonstration was performed in which bumps were created on Si chips through Al sputtering and lithography processes. Subtractive lithography etching was the only effective process for the bonding of bumps, and Ar plasma treatment magnified the joint strength. The actual joint shear strength was positively proportional to the simulated maximum stress. Specifically, the shear strength reached 44.6 MPa in the case of ultrasonic bonding for the little Al square bumps.

Limit State Philosophy in Pipeline Design

1987 ◽  
Vol 109 (1) ◽  
pp. 9-22 ◽  
Author(s):  
C. P. Ellinas ◽  
P. W. J. Raven ◽  
A. C. Walker ◽  
P. Davies
Keyword(s):  
Structural Analysis ◽  
Safety Factor ◽  
Current Knowledge ◽  
Limit State ◽  
Structural Behavior ◽  
Major Conclusion ◽  
Safety Factors ◽  
Suitable Framework ◽  
General Aspects ◽  
Pipeline Design

This paper considers the application of the limit state philosophy of structural analysis to pipeline design. General aspects of the philosophy are discussed and the approach to the evaluation of safety factors is reviewed. The paper further considers the various limit and serviceability states which would be relevant to a pipeline and reviews the various factors which may require consideration, before a code embodying the limit state philosophy could be formulated. A review of the state of current knowledge on various aspects of geometry and material characteristics, loading and structural behavior is presented. It is intended that such a review can be used as the basis for a larger study to provide guidance and data for the evaluation of rational levels of safety factor. The major conclusion reached by the authors is that a limit state philosophy would be valuable in providing a suitable framework, which may highlight the significant aspects of pipeline design and which can most easily accommodate new requirements and results obtained from research.

Finite Element Analysis of Motor Box for EBZ160 Horizontal Roadheader

2015 ◽  
Vol 1090 ◽  
pp. 233-237
Author(s):  
Ji Jun Miao ◽  
Ri Sheng Long
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Safety Factor ◽  
Stress And Strain ◽  
Element Analysis

In order to solve the cracking and poor reliability problems of motor box of Horizontal Roadheader, the static structural FEA (Finite Element Analysis) of cutting arm & motor box of the EBH160 Horizontal Roadheader was conducted, and the stress and strain contours of FEA were obtained. By comparing the calculated results, the safety factor of cutting arm & motor box was 1.36, which provides a reference for the optimal design of cutting arm & motor box.

Improved defibrillator waveform safety factor with biphasic waveforms

1983 ◽  
Vol 245 (1) ◽  
pp. H60-H65 ◽  
Author(s):  
J. L. Jones ◽  
R. E. Jones
Keyword(s):  
Safety Factor ◽  
Voltage Gradient ◽  
Excitation Threshold ◽  
Efficacy And Safety ◽  
Myocardial Cells ◽  
Safety Factors ◽  
Adult Type ◽  
Intracellular Microelectrodes ◽  
Cultured Myocardial Cells

Excitation thresholds and arrhythmias were studied in "adult-type" cultured chick embryo myocardial cells after electric field stimulation with biphasic, truncated, and rectified underdamped RLC (resistance-inductance-capacitance) type waveforms, to test the hypothesis that the negative phase of biphasic waveforms ameliorates membrane dysfunction induced by the initial positive portion. Photocell mechanograms and intracellular microelectrodes monitored extrasystoles and depolarization-induced arrhythmias. Rectifying or truncating biphasic waveforms did not alter the excitation threshold. However, shock intensities producing specific postshock arrhythmias or a specific severity of postshock prolonged depolarization differed significantly when biphasic waveforms were truncated or rectified. The voltage gradient producing a specific dysfunction was 12-14% lower for the truncated version than for the biphasic; that for the rectified version was 17-27% lower than for the biphasic version (although both contained the same energy). Safety factor, the ratio between shock intensity producing specific dysfunction and that producing excitation, was determined for each waveform. Biphasic waveforms had larger safety factors than truncated or rectified waveforms. Since safety factor, as measured in cultured myocardial cells, closely corresponds with in situ defibrillating effectiveness (14), the significantly higher safety factors of biphasic waveforms suggest that carefully shaped biphasic waveforms might improve the efficacy and safety of cardiac defibrillation procedures.

Redesign of the Femoral Stem for a Total Hip Arthroplasty for Additive Manufacturing

2018 ◽  
Author(s):  
Bradley Hanks ◽  
Shantanab Dinda ◽  
Sanjay Joshi
Keyword(s):  
Additive Manufacturing ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Lattice Structure ◽  
Stress Shielding ◽  
Patient Specific ◽  
Hip Implants ◽  
Hip Implant ◽  
Total Hip ◽  
Multiple Materials

Total hip arthroplasty (THA) is an increasingly common procedure that replaces all or part of the hip joint. The average age of patients is decreasing, which in turn increases the need for more durable implants. Revisions in hip implants are frequently caused by three primary issues: femoral loading, poor fixation, and stress shielding. First, as the age of hip implant patients decreases, the hip implants are seeing increased loading, beyond what they were traditionally designed for. Second, traditional implants may have roughened surfaces but are not fully porous which would allow bone to grow in and through the implant. Third, traditional implants are too stiff, causing more load to be carried by the implant and shielding the bone from stress. Ultimately this stress shielding leads to bone resorption and implant loosening. Additive manufacturing (AM) presents a unique opportunity for enhanced performance by allowing for personalized medicine and increased functionality through geometrically complex parts. Much research has been devoted to how AM can be used to improve surgical implants through lattice structures. To date, the authors have found no studies that have performed a complete 3D lattice structure optimization in patient specific anatomy. This paper discusses the general design of an AM hip implant that is personalized for patient specific anatomy and proposes a workflow for optimizing a lattice structure within the implant. Using this design workflow, several lattice structured AM hip implants of various unit cell types are optimized. A solid hip implant is compared against the optimized hip implants. It appears the AM hip implant with a tetra lattice outperforms the other implant by reducing stiffness and allowing for greater bone ingrowth. Ultimately it was found that AM software still has many limitations associated with attempting complex optimizations with multiple materials in patient specific anatomy. Though software limitations prevented a full 3D optimization in patient specific anatomy, the challenges associated such an approach and limitations of the current software are discussed.

Sign in / Sign up

Export Citation Format

Share Document