ORCID Profile
0000-0001-9171-5594
Current Organisation
University of South Australia
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Publisher: MDPI AG
Date: 10-04-2021
DOI: 10.3390/MA14081895
Abstract: This paper focuses on the energy generating capacity of polyvinylidene difluoride (PVDF) piezoelectric material through a number of prototype sensors with different geometric and loading characteristics. The effect of sensor configuration, surface area, dielectric thickness, aspect ratio, loading frequency and strain on electrical power output was investigated systematically. Results showed that parallel bimorph sensor was found to be the best energy harvester, with measured capacitance being reasonably acceptable. Power output increased with the increase of sensor’s surface area, loading frequency, and mechanical strain, but decreased with the increase of the sensor thickness. For all scenarios, sensors under flicking loading exhibited higher power output than that under bending. A widely used energy harvesting circuit had been utilized successfully to convert the AC signal to DC, but at the sacrifice of some losses in power output. This study provided a useful insight and experimental validation into the optimization process for an energy harvester based on human movement for future development.
Publisher: ASME International
Date: 06-2017
DOI: 10.1115/1.4036713
Abstract: This paper presents a comprehensive experimental study in exploring the influence of key printing parameters on mechanical properties and failure mechanisms of acrylonitrile butadiene styrene (ABS) material. Three parameters with three levels—layer thickness (0.09 mm, 0.19 mm, and 0.39 mm), printing plane (XY, YZ, and ZX), and printing orientation (horizontal, diagonal, and vertical)—are considered, which form an L27 experimental design. Following L27, tensile and compressive specimens are fabricated and tested. Young's modulus, yield strength, failure strength, and strain of specimens are measured, evaluated, and compared with their injection-molded counterparts. Experimental results indicate that tensile specimens with a layer thickness of 0.09 mm and printing plane orientation of YZ-H reveal the highest stiffness and failure strength. While injection-molded specimen shows the highest yield strength, ductility of printed specimens is 1.45 times larger than that of injection-molded part. YZ along with XY specimens shows a neat and clean standard fracture failure at 45 deg, where the layers reorient themselves followed by stretching before fracture failure, thus providing sufficient ductility as opposed to ZX specimens, which fail along the direction perpendicular to the loading. Compressive XY-H and XY-D specimens have the highest stiffness and yield strength, and failure mechanisms involve initial compression followed by squeezing of layers leading to compactness followed by breakage due to tearing off or fracture of layers. The findings imply that anisotropy of fused deposition modeling (FDM) parts cannot be avoided and hence the appropriate parameters must be chosen, which satisfy the intended properties of the material subject to specific loading scenario.
Publisher: MDPI AG
Date: 16-02-2018
DOI: 10.3390/MET8020136
Publisher: ASME International
Date: 06-12-2021
DOI: 10.1115/1.4052929
Abstract: This paper presents the influence of the grinding-burnishing on surface integrity and corrosion performance of the laser-cladded AISI 431 alloys. As-cladded specimens were first ground followed by ball burnishing. To evaluate surface alteration and performance enhancement, six major properties were measured and analyzed in terms of surface roughness, porosity, microhardness, wear, and impact and corrosion resistance. Results showed that grinding-burnishing significantly improved the surface finish by lowering Ra and Rz by up to 29% and 41%, respectively, compared with grinding. Surface porosity was found to decrease by 18%. Maximum surface microhardness increased by 32% when grinding-burnishing, with a modified depth of up to 250 µm, while wear resistance in terms of volume loss increased by up to 38%. Because of hardness improvement, the grinding-burnishing increased the impact resistance by lowering the maximum indent depth by 29%. The corrosion resistance improved by increasing positive corrosion potential from −0.31 V (grinding) to −0.21 V (grinding-burnishing) and lowering corrosion current density from 1.18 × 10−3 A.cm−2 (for grinding) to 2.1 × 10−5 A.cm−2 (grinding-burnishing). Burnishing further induced grain modification in terms of grain deformation and flattening within microstructure, but no grain refinement was observed. XRD results however showed lattice deformation indicating potential compressive residual stress generated by burnishing. Overall, it is imperative to say that the combined grinding-burnishing can be a viable surface modification technique to extend functional service life of the laser-cladded components.
Publisher: Springer International Publishing
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 02-2018
Publisher: Springer Science and Business Media LLC
Date: 03-2018
Publisher: IOP Publishing
Date: 05-04-2016
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 10-2017
Publisher: Springer Science and Business Media LLC
Date: 13-08-2020
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.ULTRAS.2014.11.001
Abstract: The optimum topology of bimaterial phononic crystal (PhCr) plates with one-dimensional (1D) periodicity to attain maximum relative bandgap width of low order Lamb waves is computationally investigated. The evolution of optimized topology with respect to filling fraction of constituents, alternatively stiff scattering inclusion, is explored. The underlying idea is to develop PhCr plate structures with high specific bandgap efficiency at particular filling fraction, or further with multiscale functionality through gradient of optimized PhCr unitcell all over the lattice array. Multiobjective genetic algorithm (GA) is employed in this research in conjunction with finite element method (FEM) for topology optimization of silicon-tungsten PhCr plate unitcells. A specialized FEM model is developed and verified for dispersion analysis of plate waves and calculation of modal response. Modal band structure of regular PhCr plate unitcells with centric scattering layer is studied as a function of aspect ratio and filling fraction. Topology optimization is then carried out for a few aspect ratios, with and without prescribed symmetry, over various filling fractions. The efficiency of obtained solutions is verified as compared to corresponding regular centric PhCr plate unitcells. Moreover, being inspired by the obtained optimum topologies, definite and easy to produce topologies are proposed with enhanced bandgap efficiency as compared to centric unitcells. Finally a few cases are introduced to evaluate the frequency response of finite PhCr plate structures produced by achieved topologies and also to confirm the reliability of calculated modal band structures. Cases made by consecutive unitcells of different filling fraction are examined in order to attest the bandgap efficiency and multiscale functionality of such graded PhCr plate structures.
Publisher: Elsevier BV
Date: 10-2004
Publisher: Mechanical Engineering Faculty in Slavonski Brod
Date: 09-2018
Publisher: Springer London
Date: 2007
Publisher: Springer International Publishing
Date: 2014
Publisher: Walter de Gruyter GmbH
Date: 26-09-2017
Abstract: This paper presents a numerical modelling and optimization of a new ‘star-like’ geometric texture shape with an aim to improve tribological performance. Initial studies showed that the triangle effect is the most dominant in reducing the friction. Motivated with this, a ‘star-like’ texture shape consisting of a series of triangular spikes around the centre of the texture is proposed. It is hypothesised that by increasing the triangular effect on a texture shape, the converging micro-wedge effect is expected to increase, hence increasing the film pressure and reducing the friction. Using the well-known Reynolds boundary conditions, numerical modelling of surface texturing is implemented via finite difference method. Simulation results showed that the number of apex points of the new ‘star-like’ texture has a significant effect on the film pressure and the friction coefficient. A 6-pointed texture at a texture density of 0.4 is shown to be the optimum shape. The new optimum star-like texture reduces the friction coefficient by 80%, 64.39%, 19.32% and 16.14%, as compared to ellipse, chevron, triangle and circle, respectively. This indicates the potential benefit of the proposed new shape in further enhancing the hydrodynamic lubrication performance of slider bearing contacts.
Publisher: Elsevier BV
Date: 06-2015
Publisher: IOP Publishing
Date: 03-2017
Publisher: Informa UK Limited
Date: 14-07-2014
DOI: 10.1080/10255842.2014.936856
Abstract: Cup wear and inclination on the pelvic bone are significant factors, which change the contact of the articulating surfaces, thus, impacting the long-term performance of hip implants. This paper presents a finite element (FE) analysis of the contact of the dual mobility implants under the influence of cup wear and inclination. A 3D FE model of the implant was developed with the application of equivalent physiological loading and boundary conditions. Effects of cup inclination angle ranging from 45° to 60° and the wear depth ranging from 0 to 2.46 mm equivalent to up to 30 years of the implant's life on the contact pressure and von Mises stress were investigated. Simulation results show that the contact pressure and von Mises stress decrease significantly with a modest wear depth and remains quite in-sensitive to the cup inclination angle and wear depth up to 1.64 mm. With wear depth further up to 2.46 mm, the cup thickness (i.e. cup thinning on worn region) may be more predominant than increasing of contact area between the cup and the head. The wear on the inner surface of the cup is found to rule out the overall contact pressure and stress in the implant. Furthermore, in idual and combined effects of both important parameters are analysed and discussed with respect to available clinical/laboratory studies.
Publisher: Universiti Malaysia Pahang Publishing
Date: 30-06-2020
DOI: 10.15282/JMES.14.2.2020.05.0517
Abstract: In this work, a milling dynamometer based on strain gauge with an octagonal and square ring was designed and tested. Strain gauges were attached with the mechanical rings to detect the deformation, during the machining process. Wheatstone bridge circuit was equipped with gauges to acquire the strain as voltage owing to the deformation of mechanical rings when machining takes place. The finite element analysis (FEA) was used to identify the location of maximum deformation and stress. The direction of rings and location of gauges were decided to increase the sensitivity and decrease the cross-sensitivity. Then, the cutting force was acquired through NI 6221 M series data acquisition (DAQ) card. The dynamometer had undergone a cycle of tests to verify its static and dynamic characteristics. The metrological characterization was performed according to the calibration procedure based on ISO 376 – 2011 standard. The cutting force was measured with both the dynamometers through milling experiments based on Taguchi’s L9 orthogonal array and the results were recorded. The measured cutting force varied from 300 N to 550 N. The obtained results depicted that low-cost milling dynamometer was reliable to measure the three component machining force. Overall, the square ring based dynamometer provides the better static and dynamic characteristics in terms of linearity, cross-sensitivity (4%), uncertainty (0.054%), and natural frequency (362.41 rev/s).
Publisher: MDPI AG
Date: 22-06-2021
Abstract: This paper presents recycling of selective laser sintering (SLS) waste nylon into printable filaments and parts reinforced with Mg particles. Waste nylon and waste–Mg powder mixture with 2%, 4%, and 8% Mg to nylon were extruded into the filaments. Moisture absorption, differential scanning calorimetry, and melt flow index experiments were conducted to determine the thermal characteristics, while tensile and flexural tests were conducted to evaluate mechanical properties and failure mechanisms. The results were compared with off-the-self (OTS) nylon. Waste powder was found to be extrudable and printable as FFF filament. Waste filament diameter closely matched standard filament size, while exhibiting reduced moisture absorption. High melting and crystallisation temperature for the waste nylon demonstrated a degradation of the plastic during the SLS process. Young’s modulus and ultimate tensile strength for the waste filament increased by 1.6-fold compared to that for OTS, while Mg-composite filament surpassed the waste and OTS. Waste and Mg composite dog bone results showed an increase in strength and stiffness, but the ductility deteriorated. Both flexural strength and modulus for the waste nylon increased by 13% and 26%, respectively, over OTS, and the addition of Mg enhanced flexural strength by up to 5-fold at 8% Mg over the waste. Printed surface topography demonstrated that the waste and Mg composite filaments can print the parts with desired geometric shapes and acceptable surface texture. The findings showed that recycling waste SLS powder into FFF prints would be a viable and useful alternative to disposal, given its abundance.
Publisher: American Society of Mechanical Engineers
Date: 11-11-2019
Abstract: Bone drilling is an important step in orthopedic surgeries for the reconstruction and repair of fractured bones. The main concern in bone drilling is to create holes without causing minimum damage to the bone tissues. It is well reported that high temperature and high force in drilling cause bone thermal necrosis leading to the delayed bone healing and implant failure. In the past, a significant amount of research has been conducted to understand and mitigate the issues in bone drilling. However, the current practice in bone drilling is that medical surgeons still rely on their own experience and feeling, which often causes unwanted damage to the bone. The present paper aims to provide a comprehensive review of surgical bone drilling and impending factors affecting drilling and biological performance of the bone. Current protocols and practices in tackling issues around drilling are discussed and assessed in terms of results obtained in both experimental and computational domains. This pragmatic discussion will signify the importance and challenges ahead in empowering medical surgeons to enable improved surgical outcome. Furthermore, the findings of this extensive review are expected to drive further exploration of new opportunities for developing advanced bone drilling system integrated with intelligent sensors and control technology.
Publisher: AIP Publishing
Date: 2021
DOI: 10.1063/5.0037543
Publisher: Elsevier BV
Date: 04-2013
Publisher: MDPI AG
Date: 24-04-2023
DOI: 10.3390/JFB14050242
Abstract: The present paper aims to provide an overview of the current state-of-the-art mechanical surface modification technologies and their response in terms of surface roughness, surface texture, and microstructural change due to cold work-hardening, affecting the surface integrity and corrosion resistance of different Mg alloys. The process mechanics of five main treatment strategies, namely, shot peening, surface mechanical attrition treatment, laser shock peening, ball burnishing, and ultrasonic nanocrystal surface modification, were discussed. The influence of the process parameters on plastic deformation and degradation characteristics was thoroughly reviewed and compared from the perspectives of surface roughness, grain modification, hardness, residual stress, and corrosion resistance over short- and long-term periods. Potential and advances in new and emerging hybrid and in-situ surface treatment strategies were comprehensively eluded and summarised. This review takes a holistic approach to identifying the fundamentals, pros, and cons of each process, thereby contributing to bridging the current gap and challenge in surface modification technology for Mg alloys. To conclude, a brief summary and future outlook resulting from the discussion were presented. The findings would offer a useful insight and guide for researchers to focus on developing new surface treatment routes to resolve surface integrity and early degradation problems for successful application of biodegradable Mg alloy implants.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1MA00733E
Abstract: Surface of an implant plays a key role in determining the performance as several events are associated with the surface. Modifying the surface with a bioactive coating or/and mechanical treatment can profoundly affect the success of the implant.
Publisher: MDPI AG
Date: 02-12-2018
DOI: 10.3390/MA11122443
Abstract: Hole quality in drilling is considered a precursor for reliable and secure component assembly, ensuring product integrity and functioning service life. This paper aims to evaluate the influence of the key process parameters on drilling performance. A series of drilling tests with new TiN-coated high speed steel (HSS) bits are performed, while thrust force and torque are measured with the aid of an in-house built force dynamometer. The effect of process mechanics on hole quality, e.g., dimensional accuracy, burr formation, surface finish, is evaluated in relation to drill-bit wear and chip formation mechanism. Experimental results indicate that the feedrate which dictates the uncut chip thickness and material removal rate is the most dominant factor, significantly impacting force and hole quality. For a given spindle speed range, maximum increase of axial force and torque is 44.94% and 47.65%, respectively, when feedrate increases from 0.04 mm/rev to 0.08 mm/rev. Stable, jerk-free cutting at feedrate of as low as 0.04 mm/rev is shown to result in hole dimensional error of less than 2%. A low feedrate along with high spindle speed may be preferred. The underlying tool wear mechanism and progression needs to be taken into account when drilling a large number of holes. The findings of the paper clearly signify the importance and choice of drilling parameters and provide guidelines for manufacturing industries to enhance a part’s dimensional integrity and productivity.
Publisher: Elsevier BV
Date: 08-2016
Publisher: Informa UK Limited
Date: 02-03-2020
Publisher: Inderscience Publishers
Date: 2014
Publisher: Elsevier
Date: 2017
Publisher: Wiley
Date: 18-11-2016
DOI: 10.1002/LS.1362
Publisher: ASME International
Date: 27-03-2007
DOI: 10.1115/1.2752526
Abstract: In two-dimensional (2D) free-form contour machining by using a straight (flat) end mill, conventional contour parallel paths offer varying cutting engagement with workpiece, which inevitably causes the variation in cutting loads on the tool, resulting in geometric inaccuracy of the machined workpiece surface. This paper presents an algorithm to generate a new offset tool path, such that the cutting engagement is regulated at a desired level over the finishing path. The key idea of the proposed algorithm is that the semi-finish path, the path prior to the finishing path, is modified such that the workpiece surface generated by the semi-finish path gives the desired engagement angle over the finishing path. The expectation with the proposed algorithm is that by regulating the cutting engagement angle along the tool path trajectory, the cutting force can be controlled at any desirable value, which will potentially reduce variation of tool deflection, thus improving geometric accuracy of machined workpiece. In this study, two case studies for 2D contiguous end milling operations with a straight end mill are shown to demonstrate the capability of the proposed algorithm for tool path modification to regulate the cutting engagement. Machining results obtained in both case studies reveal far reduced variation of cutting force, and thus, the improved geometric accuracy of the machined workpiece contour.
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 02-2017
Publisher: Inderscience Publishers
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 17-02-2017
Publisher: MDPI AG
Date: 28-03-2019
DOI: 10.3390/JMMP3020029
Abstract: This paper investigates the underlying interplay between the key process parameters of magnetic abrasive finishing (MAF) in improving surface quality. The five process parameters considered were the working gap, rotational speed, feed rate, abrasive amount, and abrasive mesh when MAFed independently with two abrasive particles—SiC and Al2O3. A series of experiments were conducted with an in-house built MAF tool. Based on the main effect results, a model predicting roughness reduction was developed. Results show that surface quality improvement and the underlying dominant process parameters seem unique to the abrasive type used. When MAFed with SiC, the abrasive quantity and rotational speed influence the most. On the other hand, when MAFed with Al2O3, the trend is different to SiC, i.e., the abrasive mesh size and the working gap are dominant. The prediction model was well validated by independent experiments, indicating its accuracy in estimating and optimizing the process outcome. MAF is a simple process with a complex interplay between parameters. This is very crucial when abrasive type, size, and amount to be used are concerned, which warrants a deeper investigation in terms of underlying dynamics, interactions, and the deformation of abrasive, magnetic, and workpiece materials.
Publisher: Elsevier BV
Date: 2013
Publisher: MDPI AG
Date: 25-08-2022
DOI: 10.3390/MA15175879
Abstract: This study investigated the perforation resistance behaviour of metal–plastic laminates (MPLs) when they are indented by different nose shapes. Aluminium (Al) and HDPE (high-density polyethylene) layers were bonded with a suitable adhesive in an alternative manner to prepare bilayer and trilayer MPL configurations. Quasi-static perforation experiments were performed with hemispherical, conical and blunt indenters. The effects of nose shape, layer configuration and adhesive on the force–deformation profile, perforation resistance capacity and failure mechanisms were evaluated. The results indicate that for a monolithic layer, the blunt indenter showed the highest perforation energy capacity. The conical and blunt indenters facing Al backed by HDPE gave higher perforation energy. The hemispherical indenter facing HDPE backed by Al was found to be more effective in perforation resistance. Trilayer Al–HDPE–Al showed higher perforation resistance than HDPE–Al–HDPE. Circumferential cracking, radial symmetric cracking and shear plugging were the main failure modes for Al under hemispherical, conical and blunt indenters, respectively. The adhesive contributed to an increase in the perforation energy and peak force to failure in laminates. The adhesive was shown to detach from the Al surface after Al fracturing through crack propagation, and this effect was more pronounced when the indenter faced HDPE at the front of the laminate.
Publisher: SAGE Publications
Date: 14-06-2022
DOI: 10.1177/09544089221106264
Abstract: The measurement of cutting force is one of the key factors in determining the tool condition and improving machine reliability. Therefore, the cutting force measurement becomes crucial to improve the machining process. The cutting force can be measured with piezoelectric as well as piezoresistive transducers. The force measuring transducers with later ones are cost-effective and can be easily installed in any small/medium-scale enterprise. For this approach, the selection of sensing elements is essential. The various mechanical ring elements were used for sensing the deformation. The low-cost device can be affordable in small-scale industries. Along with cutting force, it is suggested to measure the vibration signals to analyze the machining dynamics of the process. The salient features and erse force measuring transducers were discussed in this article. This paper aims to briefly review the existing design and performance of dynamometers used in modern manufacturing.
Publisher: Springer Science and Business Media LLC
Date: 10-10-2016
Publisher: Springer Science and Business Media LLC
Date: 18-02-2017
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 09-2017
Publisher: IGI Global
Date: 2019
DOI: 10.4018/978-1-5225-5445-5.CH015
Abstract: In this chapter, low elastic modulus porous Mg-Zn-Mn-(Si, HA) alloy was fabricated by mechanical alloying and spark plasma sintering technique. The microstructure, topography, elemental, and chemical composition of the as-sintered bio-composite were characterized by optical microscope, FE-SEM, EDS, and XRD technique. The mechanical properties such as hardness and elastic modulus were determined by nanoindentation technique. The as-sintered bio-composites show low ductility due to the presence of Si, Ca, and Zn elements. The presence of Mg matrix was observed as primary grain and the presence of coarse Mg2Si, Zn, and CaMg as a secondary grain boundary. EDS spectrum and XRD pattern confirms the formation of intermetallic biocompatible phases in the sintered compact, which is beneficial to form apatite and improved the bioactivity of the alloy for osseointegration. The lowest elastic modulus of 28 GPa was measured. Moreover, the as-sintered bio-composites has high corrosion resistance and corrosion rate of the Mg was decreased by the addition of HA and Si element.
Publisher: CRC Press
Date: 25-08-2022
Publisher: Informa UK Limited
Date: 05-09-2018
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 04-2018
Publisher: Informa UK Limited
Date: 22-10-2015
Publisher: Springer Science and Business Media LLC
Date: 30-12-2015
DOI: 10.1007/S11517-015-1440-2
Abstract: Wear is the major cause of implant failure, resulting in expensive revision surgeries of total hip arthroplasty. Therefore, understanding of wear mechanism and its progression is crucial to improve the physiological performance of implants. This paper presents a three-dimensional (3D) finite element (FE) wear modeling approach to estimate evolution of wear in hard-on-hard bearing components with the effect of cup abduction angle. Three bearing couples were considered, and they were PCD-on-PCD, Al2O3-on-Al2O3 and Si3N4-on-Si3N4, while the cup abduction angle varied from 35° to 70° with an increment of 5°. By adopting actual physiological hip gait loading and rotational movement for normal walking cycle in FE modeling, the contact pressure and the sliding distance were calculated to predict wear. A femoral head of 32 mm in diameter was considered, while a constant frictional contact at the inference between head and cup was used. During simulation, the geometry of cup surface was updated at a reasonable interval of gait cycles to consider the effect of wear. Wear was simulated for up to 20 million cycles which is an equivalent of 20 years of implant's life in human body. Simulation results showed that compared to other two bearing couples, the predicted linear and volumetric wear in PCD-on-PCD couple exhibited the least wear evolution for all cup angles considered. The increase in abduction angle from 35° to 70° decreases the volumetric wear by 28 % for all three bearing couples, due to the reduction in sliding distance. Steep cup angle, e.g., 70° for Al2O3 and Si3N4 bearing couples, encountered edge contact, which leads to more wear. Further, wear results were discussed and analyzed with respect to in vitro and/or clinical studies available in the literature to justify the efficacy of wear modeling.
Publisher: Informa UK Limited
Date: 12-07-2023
Publisher: Scientific Research Publishing, Inc.
Date: 2016
Publisher: Trans Tech Publications, Ltd.
Date: 06-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.443.736
Abstract: This paper presents a stress analysis of the ceramic femoral heads of hip joint prostheses with different borehole shapes to evaluate their mechanical reliability in terms of stress concentration. Under the ideal loading conditions used for ceramic rupture tests specified by the ISO 7206-5 standard, a finite element (FE) modeling is performed to determine the tensile and hoop stress distributions in the ceramic femoral heads. Two borehole shapes that are currently used in the manufacturing industry for hip joint prostheses, namely the flat bottom and keyhole, were first studied. Two new borehole shapes, dome arc and dome ellipse, were then introduced by the authors in the paper to minimize the stress concentration. It was found that while the currently used borehole shapes lead to high tensile notch stresses at their critical corners causing possible fracture failure of ceramic heads, the authors’ borehole designs can improve the mechanical reliability significantly. In addition, the effects of taper-bore contact length and their interface friction are investigated and discussed.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Springer London
Date: 2007
Publisher: MDPI AG
Date: 06-06-2021
DOI: 10.3390/JFB12020038
Abstract: Wear and wear-induced debris is a significant factor in causing failure in implants. Reducing contact pressure by using a textured surface between the femoral head and acetabular cup is crucial to improving the implant’s life. This study presented the effect of surface texturing as dimples on the wear evolution of total hip arthroplasty. It was implemented by developing finite element analysis from the prediction model without dimples and with bottom profile dimples of flat, drill, and ball types. Simulations were carried out by performing 3D physiological loading of the hip joint under normal walking conditions. A geometry update was initiated based on the patient’s daily routine activities. Our results showed that the addition of dimples reduced contact pressure and wear. The bottom profile dimples of the ball type had the best ability to reduce wear relative to the other types, reducing cumulative linear wear by 24.3% and cumulative volumetric wear by 31% compared to no dimples. The findings demonstrated that surface texturing with appropriate dimple bottom geometry on a bearing surface is able to extend the lifetime of hip implants.
Publisher: Wiley
Date: 26-09-2018
DOI: 10.1002/CNM.3149
Abstract: High stress concentration under edge loading on the cup rim contact due to micro-separation causes accelerated striping wear, fracture, and fatigue in hip implant components. While continuous effort is devoted into improving bearing design and surgical procedure to tackle the problem, the concern still has remained forcing biomedical engineers to seek for new and alternative solutions. The current paper aims to investigate the effect of a new geometry "spline" introduced at the cup's rim corner to minimise stress concentration under edge loading. Three-dimensional finite element modelling of a metal-on-metal hip implant is developed, where contact pressure, von Mises stress, and strain are predicted for three spline geometries, ie, equivalent characteristic arc radius (R = 0.5, 1.0, and 1.5 mm) at four micro-separations (of 1.0, 1.5, 2.0, and 2.5 mm) simulating edge loading on the rim contact via the application of a constant vertical load of 3 kN. The efficacy of the spline is compared with that of circular arc and sharp corner (ie, no arc) geometries. Overall, the spline outperforms both sharp corner and circular arc in reducing contact pressure, stress, and strain. The benefit of the spline over the circular arc is quite promising at larger micro-separation but fairly marginal at smaller arc radius and micro-separation. The findings indicate that, as an alternative to the circular fillet, the spline can be considered a potential geometry to be incorporated at the rim corner of the cup.
Publisher: Elsevier BV
Date: 07-2018
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 06-2016
Publisher: Defence Scientific Information and Documentation Centre
Date: 07-2022
Abstract: Edge loading leads to high contact stress at the rim of the contact. This is due to less radial clearance and excessive lateral head displacement which potentially causes implant failure. The ceramic implants have a high possibility of fracture compared with metallic implants because of above-said reasons. The present study focuses on the investigation of contact stress for the combined effect of radial clearance (0.05-0.75 mm) and micro-lateralisation conditions (1-2.5 mm) for Metal-on-Metal (M-o-M) and Ceramic-on-Ceramic (C-o-C) pairs. The contact stresses are analysed for round corners of the acetabulum cup geometry for the above-said combinations with four different arc radii (1- 4mm). Finite element modeling (FEM) of femur head with half of the acetabulum cup is considered for the current study. Contact stress values obtained for 2 mm and 4 mm round corner geometry are quite low when compared with 1 and 3 mm round corners even for larger radial clearances and high lateral head displacements. The study also showed von Mises stress value obtained for M-o-M pair is quite low for 4 mm round corner for larger radial clearance and high lateral head displacements. Similarly, in C-o-C pair the compressive stress values are minimum for 4 mm round corner. Since the stress values were minimum for 4 mm round corner geometry, it clearly indicates that even edge loading occurs and the round corner geometry would be very helpful in reducing the stress for both M-o-M and C-o-C pairs.
Publisher: Japan Society of Mechanical Engineers
Date: 2006
DOI: 10.1299/JSMEC.49.43
Publisher: Springer Science and Business Media LLC
Date: 03-2018
Publisher: Wiley
Date: 12-01-2023
Abstract: Herein, the influence of the grinding–burnishing on surface integrity, mechanical properties, and corrosion performance of Stellite 21 alloys coating deposited by laser cladding is investigated. The as‐clad specimens are first ground followed by further modification by ball burnishing at forces of 424 N and 509 N. Results show that the grinding–burnishing enhances surface finish by lowering R a from 2.6 to 0.73 μm and R z from 13 to 4.9 μm, respectively. Surface porosity is found to decrease from 3.8% to 0.9%. Hardness is increased from 609 HV to 702 HV, with a surface alteration as deep as 250 μm, while wear resistance increases by reducing worn volume from 4.15 to 2.95 mm 3 . Because of high hardness, the grinding–burnishing increases impact resistance by lowering indent depth by 20%. Grains flatten and surface undulations are remarkably reduced due to burnishing. Finally, grinding–burnishing at 509 N improves the corrosion resistance by increasing positive corrosion potential from −0.41 to −0.14 V and lowering corrosion current density from 6.34 × 10 −4 A cm −2 to 2.19 × 10 −5 A cm −2 , as compared to grinding. This synergistic grinding–burnishing can be a plausible post‐treatment route for the laser‐clad alloys.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Inderscience Publishers
Date: 2020
Publisher: Springer Science and Business Media LLC
Date: 24-05-2014
Publisher: Elsevier BV
Date: 04-2009
Publisher: Springer Science and Business Media LLC
Date: 05-04-2020
Publisher: Inderscience Publishers
Date: 2017
Publisher: Informa UK Limited
Date: 20-03-2019
Publisher: Scientific Research Publishing, Inc.
Date: 2016
Publisher: Informa UK Limited
Date: 17-04-2014
Publisher: Springer Science and Business Media LLC
Date: 02-11-2017
DOI: 10.1007/S11517-017-1739-2
Abstract: Hip implants subject to gait loading due to occupational activities are potentially prone to failures such as osteolysis and aseptic loosening, causing painful revision surgeries. Highly risky gait activities such as carrying a load, stairs up or down and ladder up or down may cause excessive loading at the hip joint, resulting in generation of wear and related debris. Estimation of wear under the above gait activities is thus crucial to design and develop a new and improved implant component. With this motivation, this paper presents an assessment of wear generation of PCD-on-PCD (poly crystalline diamond) hip implants using finite element (FE) analysis. Three-dimensional (3D) FE model of hip implant along with peak gait and peak flexion angle for each activity was used to estimate wear of PCD for 10 million cycles. The maximum and minimum initial contact pressures of 206.19 MPa and 151.89 MPa were obtained for carrying load of 40 kg and sitting down or getting up activity. The simulation results obtained from finite element model also revealed that the maximum linear wear of 0.585 μm occurred for the patients frequently involved in sitting down or getting up gait activity and maximum volumetric wear of 0.025 mm
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 09-2020
Publisher: Springer International Publishing
Date: 2019
Publisher: Elsevier BV
Date: 06-2016
Publisher: Elsevier BV
Date: 04-2016
Location: Bangladesh
No related grants have been discovered for Mohammad Uddin.