Evaluation Of Mechanical Properties Research Articles

Mechanical properties evaluation of metacarpophalangeal joint prosthesis with new titanium-nickel memory alloy: a cadaver study

ObjectiveNi-Ti memory alloys are unusual materials for hard-tissue replacement because of their unique superelasticity, good biocompatibility, high strength, low specific gravity, low magnetism, wear resistance, corrosion resistance and fatigue resistance. The current study aims to evaluate its mechanical properties and provide biomechanical basis for the clinical application of the prosthesis.MethodsTen adult metacarpophalangeal joint specimens were randomly divided into a prosthesis group (n = 5, underwent metacarpophalangeal joint prosthesis) and a control group (n = 5, underwent sham operation). Firstly, the axial compression strength was tested with BOSE material testing machine to evaluate its biomechanical strength. Secondly, these specimens were tested for strain changes using BOSE material testing machine and GOM non-contact optical strain measurement system to evaluate the stress changes. Thirdly, fatigue test was performed between groups. Lastly, the mechanical wear of the metacarpophalangeal joint prosthesis was tested with ETK5510 material testing machine to study its mechanical properties.ResultsAxial compression stiffness in the prosthesis group was greater than that in the control group in terms of 30 ° and 60 ° flexion positions (P < 0.05). There was no statistically significant difference between two groups with regards to axial compression stiffness and stress change test (P > 0.05). In the fatigue wear test, the mean mass loss in the prosthesis group’s prosthesis was 17.2 mg and 17.619 mm3, respectively. The mean volume wear rate was 0.12%. There was no statistically significant difference in the maximum pull-out force of the metacarpal, phalangeal, and polymer polyethylene pads between the prosthesis group and the control group specimens.ConclusionsNi-Ti memory alloy metacarpophalangeal joint prosthesis conforms to the biomechanical characteristics of metacarpophalangeal joints without implants, and the fatigue strength can fully meet the needs of metacarpophalangeal joint activities after joint replacement.

Optimization and fuzzy model for evaluation of mechanical and tribological properties of Al-CNT-Si3N4 based nano and hybrid composites

Silicon Nitride (Si3N4) has an extraordinary combination of high hardness, strength, toughness, and advanced properties like excellent wear and corrosion resistant, thermal shock resistance. Also, Carbon Nano Tube (CNT) has grasped interest among the researchers owing to its superior mechanical and thermal properties. Hence, the present study intents to fabricate Al matrix reinforced with Si3N4 nano particulate and Al matrix reinforced with CNT and Si3N4 particulate called hybrid composite via gravity casting route. The fabricated composites were tested for compression test, hardness and tribological test. The L9 orthogonal array was selected to conduct the tribological test in dry sliding conditions. Furthermore, SEM, an optical microscope, and image analysis tools were used to characterize the created composites. To determine the ideal operating conditions of the tribology test, analysis of variance was performed. The correlation between the input parameters and the wear rate, COF, was established using regression models. In order to predict the rate of wear with greater than 95% accuracy, a fuzzy model was developed based on the experimental data.

Applications of Machine Learning to Predict the Flexural Bearing Capacity of Hollow Core Slabs After Fire Exposure

Conventional evaluation of the overall mechanical properties and ultimate flexural capacity of prestressed hollow core slabs after a fire exposure depends heavily on the inversion of fire scene temperature. To avoid this drawback, this paper presents a new methodology which combines a generalized regression neural network (GRNN) with conventional non-destructive testing technology. Thereby, a neural network model for predicting the material performance parameters after fire exposure is obtained based on conventional testing indices. A hollow core slab bridge is used as an example, and the applicability of the trained network model is confirmed using numerical simulation and a field failure test. Results show that the overall relative error of GRNN in predicting the key performance parameters of the bridge after fire exposure is less than 10%. Further, because of the good thermal inertia of the concrete, the relative error in predicting the material performance parameters of steel after a fire is less than 5%. Moreover, the ultimate flexural capacity of the prestressed hollow core slab after a fire can be accurately evaluated by feeding the material performance parameters predicted by GRNN neural network into the finite element (FE) model.

Atomistic structural transformation of Fe-Cr-Ni single crystal alloy under uniaxial deformation using molecular dynamics simulation

The evaluation of mechanical properties, microstructure, and phase transformation of Fe-Cr-Ni alloy under different strain rates, at temperature 300 K has been done in this investigation, using molecular dynamics simulation. These properties are of utmost importance, for the design and development of different grades of metals and alloys. In this study, a nano-size face center cubic (FCC) single crystal of Fe-Cr-Ni alloy has been selected to examine stress–strain response under various strain rates at room temperature through molecular dynamic simulation. In this simulation study, It was found that, the evolution of an alternate multilayer stack of a rectangular block of face center cubic (FCC) atoms, hexagonal close pack (HCP) rectangular block atoms and strain induced martensitic phase transformation occurred during uniaxial loading at a strain rate of 1011 s−1 at ambient temperature. It was also observed that the intersection of stacking faults is a source of dislocation. This study based on MD simulation provides an in-depth concept of the mechanical properties during mechanical and thermal processing. It also helps improve the mechanical properties of various grades of steel and other engineering materials.

Speckle-Tracking Strain Analysis for Mapping Spatiotemporal Contractility of Induced Pluripotent Stem Cell (iPSC)-Derived Cardiomyocytes.

Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hiPSC-CMs) hold tremendous potential for cardiovascular disease modeling, drug screening, personalized medicine, and pathophysiology studies. The availability of a robust protocol and functional assay for studying phenotypic behavior of hiPSC-CMs is essential for establishing an in vitro disease model. Many heart diseases manifest due to changes in the mechanical strain of cardiac tissue. Therefore, non-invasive evaluation of the contractility properties of hiPSC-CMs remains crucial to gain an insight into the pathogenesis of cardiac diseases. Speckle tracking-based strain analysis is an efficient non-invasive method that uses video microscopy and image analysis of beating hiPSC-CMs for quantitative evaluation of mechanical contractility properties. This article presents step-by-step protocols for extracting quantitative contractility properties of an hiPSC-CM system obtained from five members of a family, of whom three were affected by DiGeorge syndrome, using speckle tracking-based strain analysis. The hiPSCs from the family members were differentiated and purified into hiPSC-CMs using metabolic selection. Time-lapse images of hiPSC-CMs were acquired using high-spatial-resolution and high-time-resolution phase-contrast video microscopy. Speckled images were characterized by evaluating the cross-correlation coefficient, speckle size, speckle contrast, and speckle quality of the images. The optimum parameters of the speckle tracking algorithm were determined by performing sensitivity analysis concerning computation time, effective mapping area, average contraction velocity, and strain. Furthermore, the hiPSC-CM response to adrenaline was evaluated to validate the sensitivity of the strain analysis algorithm. Then, we applied speckle tracking-based strain analysis to characterize the dynamic behavior of patient-specific hiPSC-CMs from the family members affected/unaffected by DiGeorge syndrome. Here, we report an efficient and manipulation-free method to analyze the contraction displacement vector and velocity field, contraction-relaxation strain rate, and contractile cycles. Implementation of this method allows for quantitative analysis of the contractile phenotype characteristics of hiPSC-CMs to distinguish possible cardiac manifestation of DiGeorge syndrome. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Differentiation of iPSCs into iPSC-derived cardiomyocytes (iPSC-CMs) and metabolic selection of differentiated iPSC-CMs Support Protocol 1: Culture, maintenance, and expansion of human iPSCs Support Protocol 2: Immunohistochemistry of iPSC-CMs Basic Protocol 2: Time-lapse speckle imaging of iPSC-CMs and speckle quality characterization Support Protocol 3: Enhancement of local contrast of videos by applying contrast limited adaptive histogram equalization (CLAHE) to all frames Support Protocol 4: Evaluation of average speckle size Support Protocol 5: Evaluation of average speckle contrast Support Protocol 6: Determination of relative peak height, Pc(x), of consecutive images acquired from video microscopy of iPSC-CMs Basic Protocol 3: Speckle tracking-based analysis of beating iPSC-CMs Support Protocol 7: Validation of sensitivity of the speckle tracking analysis for mapping the contractility of iPSC-CMs Basic Protocol 4: Data extraction, visualization, and mapping of contractile cycles of iPSC-CMs.

Comparative Evaluation of Mechanical Properties and Bond Strength of Glass Ionomer Cement reinforced with three different concentrations of Silver Nanoparticles as against Conventional Glass Ionomer Cement in Primary Teeth.

Introduction: Restorative dental materials are defined as substances that are used to repair, replace, or enhance a patient's teeth. Various materials used in paediatric dentistry are zinc oxide eugenol, glass ionomer cement, resin composite, calcium hydroxide, silver amalgam, giomers etc. GIC is a biocompatible material having a low thermal expansion coefficient and fluoride release property. There are still a few drawbacks of GIC due of their poor mechanical properties therefore addition of Silver Nanoparticles demonstrated improved mechanical and bactericidal capabilities. There hasn't been much study on the quality of the bond contact between silver nanoparticles and dentin, as well as the color's durability. Aim: To evaluate and compare the mechanical properties and bond strength of Glass ionomer cement reinforced with three different concentrations of silver nanoparticle as against conventional glass ionomer cement in primary Teeth. Materials and Method: Silver nanoparticles will be prepared using three chemicals namely, silver nitrate, sodium citrate and tannic acid. Traditional GIC (GC Fuji II, GC Corporation, Tokyo, Japan) will be purchased. Three different concentrations of silver nanoparticles will be prepared i.e., 0.2, 0.4, and 0.6%. The GIC specimens will then be divided into 4 groups: GIC without silver nanoparticles (AgNPs),0.2%,0.4% and 0.6% AgNPs. Mechanical properties will be checked such as compressive, tensile, and bond strength using Universal Testing Machine. Expected Results: GIC reinforced with silver nano particles is expected to have better mechanical strength, less microleakage and wear resistance, greater fracture resistance and adhesive bond strength. Conclusion: GIC reinforced with silver nano particles will be expected to have better mechanical and physical properties than conventional Type II GICs and is expected to be a promising material for restoration in primary teeth.

Evaluation of mechanical property of banana HDPE composite through experiment and artificial neural network (ANN)

In this study, two post-curing techniques using microwave and oven were utilized to examine the mechanical characteristics and behavior of composites reinforced with banana fibers with its matrix made of high-density polyethylene polymer. The research involved experimental work through tensile tests and predictive modelling using the artificial neural network (ANN). The first part of the research involved the collection of datasets which were gathered from the tensile tests based on the ASTM D638 using dog bone specimens of various fiber percentages to compare the mechanical properties such as the specific energy and maximum load after post-curing using an oven and microwave at various powers and time. The trend and behavior of the composite due to the fiber percentages and the effects of post curing methods were analyzed. The second part of the research involved the ANN approach to predict the maximum gage length based on the data collected from the experiments using inputs such as the fiber content, maximum load, and displacement. Further optimization was done on the ANN model by fine-tuning variables such as the learning function, transfer function, and number of neurons to predict the stress and strain values. The accuracy of the results was calculated using statistical evaluation equations. The optimized settings were utilized to generate the predicted results and the deviation from the experimental results were evaluated.

Shear punch testing for evaluation of mechanical properties of post heat-treated Inconel 718 nickel-based superalloy fabricated by additive manufacturing

Shear punch testing, as a cost-efficient miniature testing technique for investigating the mechanical properties under shear loading conditions, was utilized for the first time to elucidate the effect of post heat-treatment on the mechanical properties of additively manufactured Inconel 718 superalloy. Homogenization heat treatment was performed for the dissolution of undesirable Laves phase; while the aging treatment was performed on both as-built and homogenized superalloys for age hardening by precipitation of strengthening phases such as γ˝ phase. Better aging response and consequently superior shear properties were obtained by aging from the as-built condition, which were ascribed to the high dislocation density and more homogeneously dispersed precipitates in the microstructure. Moreover, by comparing the shear yield stress (SYS) with the tensile yield stress (TYS) and ultimate shear strength (USS) with ultimate tensile strength (UTS), the relationships of TYS = 1.71 × SYS and UTS = 1.72 × USS were obtained, which reveal that the experimental data points follow the von Mises criterion. Accordingly, these simple and useful formulae are consistent with the general expectations from the plasticity theory, and hence, it is possible to estimate the tensile or shear properties by performing one of these tests.

Experimental evaluation of mechanical properties and microstructure for recycled aggregate concrete collaboratively modified with nano-silica and mixed fibers

The present study was conducted to meet the demand of the construction schedule for emergency repair and construction in special projects by using the recycled aggregates produced by mechanically crushing the demolished materials on-site. The study aims to modify recycled aggregate concrete (RAC) by incorporating silica nanoparticles (NS) and mixed fibers together to meet the needs of the above special project. Here, the properties of 21 kinds of concrete with different NS contents and mixed proportions of fibers were tested, including their fresh properties, hardening properties and microstructure. Their working properties in the fresh state were studied by measuring slump and unit weight; while the mechanical properties after hardening were mainly evaluated in terms of compressive strength, splitting tensile strength, modulus of elasticity and flexural strength, and here the flexural toughness as well as the residual strength of the specimens were calculated using two methods. In addition, the effects of different NS contents, steel fibers and polyvinyl alcohol (PVA) fibers on crack development and water absorption were investigated in the microstructure. The pores between the cement matrix, interfacial transition zone (ITZ) and fibers and how they are alteredby NS were characterized by SEM and 3D-CT scans. All these results indicate that NS content has a significant effect on both the workability and mechanical properties of RAC, that steel fibers are beneficial to improve the overall mechanical index of RAC, while PVA fibers have a limited enhancement effect, and that NS particles in the microstructure help to fill the pores of 0.001–0.01 mm3 volume in the cement matrix and improve the performance of the ITZ.

Sustainable mechanical properties evaluation for graphene reinforced Epoxy/Kevlar fiber using MD simulations

Uniform filler dispersion and fillers, such as nanomaterials, with distinct but superior qualities compared to the typical matrix component can be used to create high performance composites. The current study used molecular dynamics simulations to investigate the effect of graphene reinforcement on the mechanical properties of Kevlar/Diglycidyl Ether of Bisphenol-A (DGEBA). Diethyl toluene diamine (DETDA) serves as the curing agent for DGEBA, and graphene is randomly reinforced at 1, 1.5, and 2 weight percent in the DGEBA/DETDA epoxy matrix. A layered (epoxy-Kevlar-epoxy, EKE) is constructed by maintaining Kevlar fibre in horizontal position in between the graphene-reinforced DGEBA/DETDA as illustrated in the figure. Energy minimization, geometry optimization, and dynamics are used to further stabilise the constructed structure. The method of constant strain is used to determine mechanical parameters. The MD simulation revealed that mechanical properties increased with increasing graphene content, with 21.42%, 36.47%, and 42.49% for 1, 1.5, and 2 weight percentages of graphene, respectively, when compared to pure EKE. The increasing trends in elastic moduli corroborate the experimental findings. The ultimate strength increases as graphene content increases.

Evaluation of mechanical and water absorption properties of kevlar/carbon/basalt fibers reinforced nano cellulose particulates Bisphenol-F LY556 epoxy composite

Evaluation of mechanical and water absorption properties of kevlar/carbon/basalt fibers reinforced nano cellulose particulates Bisphenol-F LY556 epoxy composite

Investigation and Feasibility of Printing Polyoxymethylene Semi-crystalline Polymer Parts with Fused Filament Fabrication 3D Printer and Evaluation of Mechanical Properties of the Printed Samples

Investigation and Feasibility of Printing Polyoxymethylene Semi-crystalline Polymer Parts with Fused Filament Fabrication 3D Printer and Evaluation of Mechanical Properties of the Printed Samples

Facile and direct synthesis of oligocarbonate diols from carbon dioxide and their application as sustainable feedstock for polyurethane

Oligocarbonate diols (PPCDL) with carbonate content higher than 90% were successfully synthesized by the direct copolymerization of propylene oxide (PO) and carbon dioxide (CO2) using metal-free Lewis acid-base catalysts in the presence of 1,4-butanediol (BDO) as proton exchange agent (PEA). The effects of molar ratio of PO to BDO, temperature, pressure and reaction time on the copolymerization were systematically investigated. The molecular weight of the prepared oligocarbonate diols is in good linear relationship to PO/BDO feeding ratio and can be easily and precisely controlled in the range of 1000–4000 g mol−1. The detailed structures of the oligocarbonate diols were fully investigated by 1H NMR, 13C NMR, MALDI-TOF analysis. The rheological properties of synthesized PPCDL were also studied using a rheometer. Finally, polycarbonate urethanes were designed and successfully prepared using the PPCDLs as soft segment and 4,4′-diphenylmethane diisocyanate (MDI) and BDO as hard segment. The comprehensive evaluation of thermal and mechanical properties of the synthesized poly(carbonate urethane)s (PCUs) demonstrates their complete feasibility in the application of polyurethane industry.

Effect of modulation period and thickness ratio on the growth and mechanical properties of heteroepitaxial c-Ti0.4Al0.6N/h-Cr2N multilayer films

c-TiAlN/h-Cr2N multilayer thin films, with modulation period λ of 10 nm, 20 nm, and 30 nm and different Cr2N/ λ thickness ratios (25 %, 50 % and 75 %), were deposited on c-plane sapphire using reactive DC magnetron sputtering. All multilayers exhibited preferred orientation [Cr2N(0001)/ TiAlN(111)]x, regardless of the modulation period and thickness ratios. X-ray diffraction φ-scans revealed an influence of the Cr2N layer thickness on the overall orientation quality of the multilayer, where the thicker the Cr2N layer the higher orientation quality. Atomically resolved high-angle annular dark-field scanning transmission electron microscopy revealed well defined and homogeneous atom stacking in the Cr2N layers. In contrast, the cubic TiAlN layer was found to be composed of coherent cubic AlN-rich and TiN-rich regions. Additionally, the TiAlN layers were found with a higher density of grain boundaries compared to the Cr2N layers. Mechanical properties evaluation revealed that the film with a 20 nm period and 75 % Cr2N thickness ratio exhibited the highest hardness of 27.11 ± 0.72 GPa and an reduced elastic modulus of 349.1 ± 6.84 GPa. The hardness increased as the thickness of Cr2N increased, until reaching 10 nm, after which it remained at a high level (∼ 25 GPa).

Design and evaluation of physical, mechanical and micro-structural properties of eco-friendly binary-blended mortars using biomass bottom ash or construction and demolition waste powder

In recent decades, waste production from biomass-fuelled power plants, as well as from building and civil engineering works construction and demolition, has increased considerably. The possibility of recovering this waste type as supplementary cementitious material (SCM) in manufacturing cement is a strategic tool for achieving the objective of reducing CO2 emissions by at least 55% (“Fit for 55″ by 2030). In this research work, the feasibility of incorporating 5%, 10%, 15% and 20% biomass bottom ash (BBA) and mixed powder from construction and demolition waste (CDWm) in the design of new eco-friendly binary cements was evaluated. To achieve this, the chemical, physical and mineralogical characterisation of the wastes was carried out; as well as a physical, mechanical and micro-structural characterisation of the pastes and mortars manufactured. The results showed that the new cements with BBA or CDWm meet the regulatory requirements for initial setting time, soundness and resistance. The mortars made with BBA also developed greater compressive strength and presented lower porosity at a later age than the reference mortar and the mortars made with CDWm. Finally, the new binary cements made with 15% and 20% BBA meet the requirements set forth in EN 197-1 for CEM IV/A cements, making them suitable for use in construction.

High-throughput evaluation of mechanical properties of biomedical Ti alloys by digital image correlation and acoustic emission

Acoustic emission and digital image correlation (DIC) were used to determine mechanical properties of six biomedical alloys from a single compression deformation experiment. Layered sample of six Ti-(20–35)Nb-7Zr-0.2O alloys was prepared by spark plasma sintering. All six layers were deformed in compression at once. Advanced use of DIC allowed us to separate the deformation in each layer and determine the flow curve of each alloy. Simultaneous use of acoustic emission provides insight into active plastic deformation mechanisms. Nb content in the studied alloys significantly affects ductility of the material as well as shape of the compression flow curve suggesting different plastic deformation mechanisms in the studied alloys. Presented methods provide high-throughput determination of mechanical properties allowing efficient optimization of alloy composition.

Evaluation of microstructure, mechanical properties, and corrosion resistance for Ti-doped inconel 625 alloy produced by laser directed energy deposition

Additive manufacturing (AM) technology has opened up new opportunities to efficiently synthesize alloys and produce near-net shape components. In this study, Ti-doped Inconel 625 materials were produced to promote in-situ alloying between pre-alloyed Inconel 625 and elemental Ti powders by laser directed energy deposition, a predominant metal AM technique. The microstructure, mechanical properties, and corrosion resistance were evaluated before and after Ti addition and heat treatment (solutionization followed by aging). It was found that Ti addition alone did not cause significant change in microstructure. However, heat treatment caused migration of segregation species from interdendritic regions to intermetallic precipitates which occupy grain boundaries, and it modestly increased the average grain size for Ti-doped samples. Crystallographic analysis revealed a very strong cubic texture of Ti-doped Inconel 625 which only slightly decreased after heat treatment. Without heat treatment, the addition of Ti was not found to be beneficial to tensile properties of Inconel 625, due to the formation of thin Ti oxide films. However, the combination of Ti addition and heat treatment led to modest increase in hardness and tensile strength compared to the as-built Ti-free case, which is believed to result from the effects of Ti solid solution hardening, precipitation hardening, and dissolution of oxide films. Also, the combined effects can explain the pronounced increase of ductility for Ti-doped Inconel 625 after heat treatment, where the beneficial effect from oxide film dissolution could be dominant. In addition, under the as-built condition, corrosion resistance was found to be slightly higher for Ti-doped materials, but after heat treatment it dropped for Ti-doped materials while almost did not change for Ti-free case.

Evaluation of Structural Stability, Mechanical Properties, and Corrosion Resistance of Magnesia Partially Stabilized Zirconia (Mg-PSZ).

Nano Zirconia (ZrO2) has been used in dental implants due to having excellent mechanical properties and biocompatibility that match the requirements for the purpose. Zirconia undergoes phase transformation during heating: monoclinic (room temperature to 1170 °C), tetragonal (1170 °C to 2370 °C), and cubic (>2370 °C). Most useful mechanical properties can be obtained when zirconia is in a multiphase form or in partially stabilized zirconia (PSZ), which is achieved by adding small amounts of a metal oxide dopant, such as MgO (magnesia). This study aimed to synthesize nano Mg-PSZ from a local resource found in West Kalimantan, Indonesia, and examine its structural stability, biochemical stability, and mechanical properties. Nano Mg-PSZ was prepared from a zircon local to Indonesia, from West Kalimantan Province, MgSO4∙7H2O, and polyethylene glycol (PEG)-6000 was used as a template. The obtained t-ZrO2 after calcination at 800 °C was shown to be stable at room temperature. The highest percentage of the t-ZrO2 phase was obtained at Zr0.95Mg0.05O2 with a variation of 99.5%. The hardness of Mg-PSZ increased from 554 MPa for ZrO2 without MgO doping to 5266 MPa for ZrO2 with a doping of 10% MgO. An in vitro biodegradation test showed that the greater the concentration of MgO in doping the ZrO2, the greater the degradation resistance of Mg-PSZ in simulated body fluid (SBF) solution.

Representative volume element (RVE) based FEA investigation on the plastic flow behaviour of friction-stir processed AA7075/Si3N4composite under constrained deformation conditions

In the present investigation, the Si3N4reinforced (with a weight percentage of 2.5%, 5% and 7.5%) AA7075-based metal matrix composite has been developed by friction-stir processing. Further, a micro-mechanical representative volume element (RVE)-based finite element analysis (FEA) model has been developed for the evaluation of mechanical properties and plastic flow behaviour of developed composite material in uniaxial conditions. Moreover, a macro-mechanical-based static indentation finite element model has been developed for predicting the plastic flow behaviour, Meyer's hardness, constraint factor (CF) and lip height around indentation as a function of average strain under constrained conditions. The results revealed that Meyer's hardness, yield strength, tensile strength and lip height were increased with the increase in Si3N4reinforced weight percentage. Further, the lip height was inversely proportional to the strain hardening exponent. It has been also observed that the CF of all three developed composite material compositions increased with the increase in average strain ( εavg) up to the transition strain ( εtr) only, after that its value was constant with further increase in average strain ( εavg).

Evaluation of mechanical properties of glued elements for model kits

The work is devoted to assessing the quality of fastening the abrasive component to the metal base by gluing on the example of a clutch disc. An assessment of the operability of the patented technique for testing for conditional shear of glued joints is given. The paper proposes a method of using foamed materials to create one‑time or single model kits for the production of missing parts for mechanical engineering.