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Orthodontic archwire rotation around its long axis, known as third-order torque, is utilised to correct tooth rotational misalignments moving the tooth root closer to or away from the cheek through engagement with an orthodontic bracket. Studying the behaviour of archwire and brackets during an applied rotation can aid in better understanding and appreciating the mechanics of third-order torque, potentially allowing for more effective orthodontic treatment protocols. Mechanically characterising archwire behaviour during third-order torque application is a complex task due to their physical scale and geometries. An advanced measurement technique was needed to address these constraints. A three-dimensional (3D) non-contact optical method using a digital image correlation (DIC) system was developed. An orthodontic torque simulator (OTS) was used to apply and measure third-order torque with 0.483 × 0.635 mm (0.019″ x 0.025″) rectangular archwires in tandem with a 3D DIC system, whereby surface deformations and strains could be computed using correlation algorithms. The 3D DIC system was implemented to enable third-order torque experimentation with the OTS while imaging the archwire and bracket surfaces. The 3D DIC system's ability to measure 3D archwire deformations and strains was verified using a finite element model, where comparisons between 3D DIC measurements and calculated results from the model were made to ensure the measurement capabilities of 3D DIC in the context of third-order torque. The 3D DIC system was then used to compare archwire behaviour between stainless steel (SS) and titanium molybdenum alloy (TMA) archwires to study potential clinical differences in archwire behaviour, in which the archwires were rotated with a custom SS rigid dowel (RD) as well as commercial Damon Q orthodontic brackets. The quantification of third-order torque and archwire deformations and strains led to the conclusion that SS archwires led to larger torque magnitudes compared to TMA archwires. The RD resulted in larger archwire strains compared to Damon Q brackets. The 3D DIC system provides a non-contact measurement technique that can further be used with third-order torque experimentation with the OTS. Image 1 • Isolated orthodontic archwire response to torsion is studied. • Finite element analysis is used to verify optical measurements. • Three-dimensional digital image correlation strain measurement method is validated. • Stainless steel and titanium molybdenum alloy archwire responses are compared. • Three-dimensional orthodontic archwire and bracket strain measurements are obtained. [ABSTRACT FROM AUTHOR]

Cascading rotor and stator in axial flux permanent magnet (AFPM) machine is a beneficial concept to increase the power density without increasing the diameter of the machine. Multi-stage AFPM can provide higher torque capability in applications requiring high power density. In this regard single-stator double- rotor (SSDR) and double-stator single-rotor (DSSR) are efficient machines compared to single -stage AFPM. Since SSDR and DSSR are also considered modular units to make multi-stage AFPM, like single-stage AFPM, this paper makes a comparison with analysis between SSDR and DSSR AFPM machines. Based on 3-D finite element analysis (FEA), the air-gap magnetic flux, voltage, current, torque, torque ripple, power and power density, efficiency are comparatively investigated to evaluate their performance. Results show that fully coreless topology only be achieved in SSDR AFPM machine with a higher power density. Finally, a prototype multi-stage coreless generator has been developed using a single stator double rotor (SSDR) configuration to justify the fully coreless concept. This prototype coreless generator eliminates eddy current losses and reduces weight, making it a suitable option for certain portable applications. [ABSTRACT FROM AUTHOR]

Research background: With the rapid development of civil engineering, the traditional low rise building model can no longer meet the needs of urbanization, and high-rise building structure has become the future development direction. In recent years, earthquake disasters occur frequently in China, which has caused huge losses to high-rise buildings. Therefore, we must strengthen the relevant research of high-rise building structures, which can make the high-rise building structural columns meet the requirements of safety performance. Therefore, the health detection and seismic performance evaluation of high-rise buildings will be of great significance. Research method: Through static elastic-plastic evaluation, we can calculate the dissipated strain energy of the structural column, which will further obtain the damage index of the structural column and obtain relevant data. Through this calculation method, we can complete the seismic performance evaluation of high-rise buildings, which is a calculation mode different from the traditional finite element software analysis. Through static elastic-plastic analysis, the seismic performance evaluation of high-rise buildings will have higher accuracy, which will build a damage index. Therefore, this paper uses a variety of research methods, mainly literature survey and empirical analysis. Through literature analysis, this paper can fully and correctly understand the methods of health detection and seismic performance evaluation of high-rise building structures at home and abroad, which will further clarify the current research level at home and abroad. Through empirical research, this paper analyzes specific examples, which can obtain more accurate results. Conclusion: In this paper, the seismic performance of high-rise buildings is comprehensively evaluated according to the damage index value of building structural columns. The simulation results show that more ideal seismic evaluation results can be obtained. [ABSTRACT FROM AUTHOR]

INCONEL® machining poses great challenges in predicting its behaviour, and exhaustive experimental evaluation of its machinability is expensive and unsustainable. Design of Experiments (DOE) can be performed without destroying components via Finite Element Analysis (FEA). However, it is paramount to establish if numerical modelling and the constitutive models can cope with an accurate predictability of INCONEL® machining. Hence, a broad review of FEA strategies will be given to systematically summarise and analyse the progress taken on INCONEL® machining predictability through FEA from 2013 to 2023 and present the most recent researchers' digital solutions, prospects, and limitations. Thanks to articles and books, this paper was conceived. The main keywords used in searching information were: "INCONEL® 718", "INCONEL® 625", "FEA", "Traditional Machining Modelling", "Johnson-Cook criteria", "ABAQUS™", "ANSYS®" and "DEFORM®". Combining these keywords was crucial to filter the current information about the evolution of INCONEL® alloy machining predictability through FEA. INCONEL® alloys FEA machining can nowadays effectively provide good quality and accurate results regarding the counterpart experiments. [ABSTRACT FROM AUTHOR]

Magnesium alloy is one of the lightest metal structural materials. The weight is further reduced through the hollow structure. However, the hollow structure is easily damaged during processing. In order to maintain the hollow structure and to transfer the stresses during the high temperature deformation, the sand mandrel is proposed. In this paper, the hollow AZ31 magnesium alloy three-channel joint is studied by hot extrusion forming. Sand as one of solid granule medium is used to fill the hollow magnesium alloy. The extrusion temperatures are 230 °C and 300 °C, respectively. The process parameters (die angle, temperature, bottom thickness, sidewall thickness, edge-to-middle ratio in bottom, bottom shape) of the hollow magnesium alloy are analyzed based on the results of experiments and the finite element method. The results are shown that the formability of the hollow magnesium alloy will be much better when the ratio of sidewall thickness to the bottom thickness is 1:1.5. Also when edge-to-middle ratio in bottom is about 1:1.5, a better forming product can be received. The best bottom shape in these experiments will be convex based on the forming results. The grain will be refined obviously after the extrusion. Also the microstructures will be shown as streamlines. And these lines will be well agreement with the mold in the corner. [ABSTRACT FROM AUTHOR]

Bronchoscopy has a crucial role in the current treatment of lung diseases, and it is typical of interventional medical instruments led by manual intervention. The scientific study of bronchoscopy is now of primary importance in eliminating problems associated with manual intervention by scientific means. However, for its intervention environment, the trachea is often treated statically, without considering the effect of tracheal deformation on bronchoscopic intervention during respiratory motion. Therefore its findings can deviate from practical application. Thus, studying kinetic problems in respiratory motion is of great importance. This paper developed a mathematical model of mechanical properties of respiratory motion to express respiratory force from the perspective of dynamics of respiratory motion. The dynamical model was solved using MATLAB. Then, a finite element model of respiratory motion was built using Mimics, and the results of respiratory force solution were used as the load of model for dynamics simulation in ABAQUS. Then, a human–computer interaction platform was designed in MATLAB APP Designer to realize parametric calculation and fitting of respiratory force, and a personalized human respiratory motion dynamics simulation was completed in conjunction with ABAQUS. Finally, experimental validation of the interactive platform was performed using pulmonary function test data from three patients. Validation analysis by respiration striving solution, kinetic simulation and experiment found that Dynamical model and simulation results can be better adapted to the individualized study of human respiratory motion dynamics. [ABSTRACT FROM AUTHOR]

A new proposal has been applied using Bridge Information Modeling associated to Terrestrial Laser Scanning TLS and photogrammetry to obtain the digital model of an existing bridge. For the laser scanning process. Thus, it was also possible to identify the pathologies and damages in the concrete of the bridge. Furthermore, it was shown how geo-information with remote sensing using the station Trimble SX 10 can be applied in area of bridge projects with less time and lower cost, in relationship to a conventional survey Asbuilt with manual survey in field. One of the innovations of this paper was to obtain the digital model of the bridge by integration of TLS and photogrammetry to obtain the 3D digital model. The new methodology consisted of acquisition of the bridge scenes through points previously implanted, making the polygonal contour of the entire bridge. Furthermore, the execution of the field survey from georeferenced points to capture the scenes during the sweep with TLS facilitated the refinement and, consequently, it was possible to obtain the digital model with the concrete damage. It was also possible to perform a complex nonlinear analysis with Finite Element with the digital model of the bridge. Therefore, it was applied a reverse analysis of the strength of the structure using the Concrete Damage Plasticity Model using ABAQUS software. Two numerical analyses were performed on the bridge; one considering only the static behavior of the bridge and another considering the dynamic behavior. In the static analysis, the behavior of the dapped-end beam of the bridge, was investigated. On the other hand, in the dynamic evaluation, the natural frequency and damping ratio for bridges with Dapped-end beams was obtained in ABAQUS through Rayleigh damping and compared with the technical literature, which presented satisfactory results. [ABSTRACT FROM AUTHOR]

Finite element (FE) analysis has emerged as the primary tool to investigate complex problems that are difficult to test clinically on living tissues, yielding valuable but not necessarily applicable information on orthodontic treatment modalities. Many studies are being published but the findings are difficult to interpret, lack in relevance, or cannot be critically appraised. In this paper, the FE modeling design and impact on the quality and outcome of research are discussed, with focus on how to narrow the gap between theory and clinical application. [ABSTRACT FROM AUTHOR]

[Display omitted] The mechanics of vascular tissue, particularly its fracture properties, are crucial in the onset and progression of vascular diseases. Vascular tissue properties are complex, and the identification of fracture mechanical properties relies on robust and efficient numerical tools. In this study, we propose a parameter identification pipeline to extract tissue properties from force-displacement and digital image correlation (DIC) data. The data has been acquired by symconCT testing porcine aorta wall specimens. Vascular tissue is modelled as a non-linear viscoelastic isotropic solid, and an isotropic cohesive zone model describes tissue fracture. The model closely replicated the experimental observations and identified the fracture energies of 1.57 ± 0.82 kJ m − 2 and 0.96 ± 0.34 kJ m − 2 for rupturing the porcine aortic media along the circumferential and axial directions, respectively. The identified strength was always below 350 kPa, a value significantly lower than identified through classical protocols, such as simple tension, and sheds new light on the resilience of the aorta. Further refinements to the model, such as considering rate effects in the fracture process zone and tissue anisotropy, could have improved the simulation results. This paper identified porcine aorta's biomechanical properties using data acquired through a previously developed experimental protocol, the symmetry-constraint compact tension test. An implicit finite element method model mimicked the test, and a two-step approach identified the material's elastic and fracture properties directly from force-displacement curves and digital image correlation-based strain measurements. Our findings show a lower strength of the abdominal aorta as compared to the literature, which may have significant implications for the clinical evaluation of the risk of aortic rupture. [ABSTRACT FROM AUTHOR]

In this paper, variation of temperature and velocity in the x-direction and the angular velocity of the nanofluids flow through triangular and rectangular and chamfer fins are investigated in the existence of a uniform magnetic field. The innovation of this paper is to investigate parameters of Mwcnt and TiO2 nanofluids passing from the different fins and blades on the stretching surface and compare their results together. Also by using FlexPDE and Design software, we were able to show all temperature and angular velocity counters in the form of diagrams and 3D images. The finite Element Method is selected for solving governing equations. The second part of the description relates to the use RSM method in the Design-Expert software. In this paper by using the RSM method, optimized the nanofluid velocity and heat transfer passing from the stretching sheet. Based on the results obtained from the angular velocity graphs and the heat transfer cantors in the Design-Expert software, the best optimization occurred for nanofluid velocity and nanofluid temperature, and angular velocity with u = 1.19 and T = 21.15 and N = 117.28. By comparison between the passing of MWCNT and TiO2 nanofluids flow on the different fins and blades, the results show that the temperature of MWCNT nanofluid around the fins has a greater value than the TiO2 nanofluids. The maximum heat transfer and temperature occurs near the rectangular fins for TiO2, and is 0.14% bigger than triangular and chamfer fins. [ABSTRACT FROM AUTHOR]

This paper presents our researching results regarding numerical calculus by Finite Element Method (FEM) of the Functionally Graded Plates (FGP). Two approching ways were used: the concept of multilayered plate and the concept of equivalent plate. By using of the multilayer plate concept, the continuous variation of the material law is replaced by a step variation; the layers have homogeneous and isotropic properties, with values established according to the methodology presented in this paper. When the equivalent plate concept is used, the FGP is replaced by a completely homogeneous and isotropic plate, but with fictitious properties that lead to a behavior similar to the real plate. The significance of the study consists in the elaboration and presentation of the FGPs calculus models, which can be approached with the existing current means, available to any researcher. The aim of this study is to enrich the knowledge regarding the numerical calculus, with the finite element method, of the FGP, using the current general knowledge and software products. The objectives of our study were to develop models and methodologies for calculus by FEM, available immediately. The results of the numerical simulations were validated by comparison with the adopted analytical solution. The use of the Ansys program, with the general options, available in many professional program by FEM, is still a reliable element in the numerical results and the validation of the results of our study. The methodologies, observations and conclusions are valid for any of these material laws presented in this paper. [ABSTRACT FROM AUTHOR]

The geoelectric fields induced during geomagnetic disturbances (GMD) may affect the normal operation of technological systems at the Earth's surface. The non-uniform Earth conductivity structure, especially large lateral conductivity contrasts, can lead to the enhancement of geoelectric fields near boundaries such as a coastline. In this paper, we give an overview of the applicability of a two-dimensional finite element method (2D-FEM) for studying lateral variations of the Earth's conductivity, which can be considered as one of magnetotelluric sounding forward modelling methods, including both the E and the H polarization cases. Then the spatial distribution of the geoelectric field near a continent-ocean boundary is calculated with different models. This is compared with analytic solutions for simple models to verify the accuracy of the FEM modelling, which is calculated by using the ANSOFT software. More realistic scenarios are then developed to emphasize the advantages of FEM. The factors influencing the coast effect are discussed. Results show that frequency, the shape of seafloor boundaries, and the depth of ocean have a significant impact on the geoelectric fields. Therefore, these factors should attract more attention when assessing risk for man-made conducting systems located within the coastal influence range. [ABSTRACT FROM AUTHOR]

Processing waste tires into rubber granules for secondary use can effectively alleviate the problem of environmental pollution. Therefore, this paper prepares foam concrete by replacing cementitious materials with recycled rubber granules to recycle resources. The dry density, water absorption, cubic compression, and prismatic flexure tests are carried out with the foam admixture and rubber substitution rate as the test parameters to study the effects of foam admixture and rubber substitution rate on the performance of foam concrete. Using Monte Carlo method simulation and non-linear fitting, a numerical analysis model was developed to predict recycled rubber foam concrete's mechanical properties. The ABAQUS finite element simulation method was used to explore the changes in the stress–strain relationship and damage development of the recycled rubber foam concrete, combined with microscopic observation, SEM, and XRD tests to reveal the specimens' damage mechanism, microscopic morphology, and physical structure. The experimental results show that the foam admixture has a more significant effect on the specimens' dry density, water absorption, and strength index than the effect of the rubber replacement rate. In addition, the strength prediction model, strength conversion model, and uniaxial compression finite element model of recycled rubber foam concrete were established. [ABSTRACT FROM AUTHOR]

The energy absorption structure of a train is an important part of passive safety protection during train collisions and is the last line of defense to protect both passengers and trains. In the design process of a train energy absorption structure, improved stability and greater energy absorption capacity is required. A cutting anti-climbing energy absorption structure offers good stability and energy absorption in a collision, but it can easily generate considerable heat in the energy absorption process. Therefore, it is important to conduct thermal–solid coupling simulations and crashworthiness optimization for cutting energy absorption structures. To improve the passive safety protection capability of high-speed trains, this paper experimentally and numerically explored the crashworthiness of a cutting-type energy-absorbing structure composed of an anti-creeper device, an energy-absorbing tube, cutting knives and knife-supporting tools. By adopting the Johnson–Cook material model, a finite element model was developed to study its energy absorption characteristics in a coupled heat–solid state. The effects of cutting depth (D), cutting knife front angle (A) and cutting width (W) on energy absorption (EA), cutting platform force (F mean) and peak cutting force (PCF) were analyzed based on the validated simulation model. The results showed that EA , F mean and PCF increase with increasing D and W , while EA , F mean and PCF decrease with increasing A. The GRSM was employed as the optimization algorithm, and a gain matrix–cloud model optimal worst method (G-CBW) multiobjective decision algorithm was proposed to obtain the most satisfactory configurations from the Pareto front solution. The relative errors from the optimal and finite element results of EA , F mean and PCF were 3.5%, 2.1% and 2.2%, respectively. All the crashworthiness indicators were improved considerably. [ABSTRACT FROM AUTHOR]

When landing on the lunar surface, the astronauts need to wear the spacesuit and fly the lunar module in a standing posture. At this time, the astronauts bear the impact from the vertical and horizontal directions at the same time. In order to ensure the safety of the astronauts in bearing the impact load and experiencing the second collision, it is necessary to determine the impact load threshold and vulnerable parts of impact collision that the human body can bear. In this paper, the explicit finite element analysis software LSDYNA is used to simulate and analyze the modified Hybird III dummy model, and the responses of various parts of the human body are obtained. After analysis, the following conclusions are drawn:①Under the combined impact load, the longitudinal load has a great impact on the injury of human lower limbs, and the transverse load has a little impact.②Under the boundary conditions in this paper, it is recommended that the peak value of longitudinal load borne by the human body should not exceed 7g and the peak value of transverse load should not exceed 3G.③Under the action of transverse loads in different directions, the human head, chest and waist are prone to secondary collision with spacesuit, and the neck is the most vulnerable to damage, so it is necessary to fully protect the neck. [ABSTRACT FROM AUTHOR]

The emerging concept of mechanical meta-materials has gained increasing attention in recent years, partly due to advances in additive manufacturing techniques (additive manufacturing, 3D printing) that have allowed the fabrication of materials with arbitrarily complex micro / nanostructures. The designed geometry of these structures gives rise to unprecedented or rare mechanical properties that can used to create advanced elements with new, unprecedented functions. This paper presents the method of prototyping a vibro-isolator made of a material that has the properties of storing and disposing of mechanical vibration energy and that can freely be shaped by modern manufacturing techniques. An example of a vibration isolator of the proprietary concept analyzed, using the concept of stepped and adding elements. The method is based on the use of two main tools. Mechanical properties verified by analyzing the frequency and mode of free vibrations of the prototype using the finite element method. The same CAD model of the vibro-isolator prototype produced by 3D printing. The paper presents one of the production techniques, which is 3D printing in SLS (Selective Laser Sintering) technology, and the SolidWorks and Comsol Multhiphysics software used in the CAD / CAE prototyping method. [ABSTRACT FROM AUTHOR]

This paper introduces a model of sound energy harvesting that operates at a low frequency of less than 200 Hz. This investigation focuses on the produced outcomes when the vibrations of sound energy are converted into electricity. Sound vibrations are received from outside sources and pass through a piezoelectric barrier (wall) equipped with 4*3 array of energy harvesting elements of lead zirconate titanate (PZT-5H) cantilever plates which are constructed to harvest noise in the form of sound from passing trains and vehicles on roads. This paper covers how sound vibrations change into electrical energy at two sound pressure levels (85 dB and 100 dB for environmental noise of road vehicles and railways, respectively). Furthermore, the effects of changing the pressure level on the generated voltage for the intended model have been studied as well as the effects of increasing the piezoelectric plate number on the voltage generated for the 85 dB pressure level. The simulation is conducted numerically using the Finite Element Method FEM (COMSOL). An analytical model of a literature paper is used and simulated using MATLAB to be compared with the FEM results and found to be completely converged. Afterward, to figure out the relationship between voltage and sound pressure level, an equation is derived analytically. According to simulation results, 15 V and 18.2 V are produced for an incoming acoustic pressure level of 85 dB and 100 dB, respectively. Two models are compared, an array of beams with similar dimensions and a single beam with a volume that equals the dimensions of all array beams; it is observed that the array of beams produced 33.9 % more voltage than a single beam with the same volume. The comparison of the proposed model results with experimental literature results is conducted and exhibited an excellent convergence. [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical investigations of the seismic performance of a novel self-centering (SC) hollow-core (HC) fiber-reinforced polymer (FRP)-concrete-steel (SC-HC-FCS) bridge column. This new structure is fabricated by mounting external energy dissipators (ED) and applying unbonded post-tensioned (PT) basalt FRP (BFRP) tendon to the conventional HC-FCS column that consists of an outer FRP tube and an inner steel tube, with the space between filled with concrete. The SC-HC-FCS column combines the advantages of accelerated bridge construction and self-centering. The effects of the initial prestress force values and the configuration of the energy-dissipated aluminum bar on the column performance are studied. Based on the experimental and numerical results, it is found that the proposed SC-HC-FCS column shows adequate self-centering and energy dissipation capacities. However, it is required to properly select the configuration and material properties of the aluminum bar as energy dissipators to further refine the seismic resistance of the SC-HC-FCS column. [ABSTRACT FROM AUTHOR]

Fractured formations lead to insufficient contact or loss of contact between the drill bit and rocks, which subsequently causes notable fluctuation in weight-on-bit due to flexible drill strings. This paper presents a robust integrated control design to suppress weight-on-bit fluctuation. First, a finite element drill-string longitudinal model is employed as the basis of control design, which has been verified using actual run data. The integrated controller contains a proportional–integral (PI) controller and a dynamic output feedback controller, dealing with the system's first-order and high-order dynamics. The dynamic output feedback controller only needs to focus on the system's high-order dynamics since the controller synthesis is based on the pre-designed PI controller. The controller decreases the flexible mode amplitude from disturbance to the output channel through H-infinity loop shaping, making the closed-loop system less flexible. The numerical results demonstrate that the developed approach can effectively suppress weight-on-bit fluctuation due to drill-string flexibility when drilling in fractured formations. • Suppress weight-on-bit (WOB) fluctuation caused by flexible drill strings and fractured formations in the drilling process. • A finite element drill-string model and a modified bit–rock interaction model in fractured formations are presented. • A robust integrated controller based on a two-step design procedure is presented. • Separate control design for the system's first-order and flexible modes. [ABSTRACT FROM AUTHOR]

This paper presents a hybrid Smoothed Particle Hydrodynamics (SPH) – Finite Element Method (FEM) solver for metal cutting simulations on Graphics Processing Units (GPU). For the first time in chip formation simulation, the heat transfer between an SPH model of the workpiece, and a transient FEM temperature model for the cutting tool, is established. For validation, the performance of the modeled thermal contact between two numerical domains is compared with a commercial FEM software. The sensitivity of the implemented SPH-FEM contact parameters is investigated for the first time and further insights into the thermal modeling of cutting simulations are generated. Overall, the newly developed hybrid model saves the computational time on the cutting tool side in the pure SPH method and enables more efficient high-fidelity cutting simulations. By clearly defining the thermal contact at the tool-chip interface, the simulated tool surface temperature agrees well with the experimental measurements in the literature. [ABSTRACT FROM AUTHOR]

Tip timing signal analysis has been applied to the online condition monitoring of high-speed blades. However, traditional tip timing analysis methods are not suitable for low-speed flue gas turbines. Therefore, this paper proposes a novel blade tip timing signal analysis method based on an investigation of the dynamic response characteristics of low-speed blades. First, the finite element modal theory is introduced to analyze the characteristics of blade damage. Second, an equivalent cantilever beam analysis model of flue gas turbine blades is established under complex environment and working conditions. In order to monitor the variation of local stiffness, a damage identification method based on the variation of the free end deflection of the equivalent cantilever beam is proposed. Finally, a rotating blade tip timing monitoring testing rig is established to verify the feasibility of the proposed method. The results show that the cracks originating at about 80% of the blade height have the greatest influence on blade stiffness, followed by blade root. The calculated blade damage parameters are 4.8464 mm and 3.7588 mm, and the crack influencing factors are 4.7476 and 3.6822, respectively, indicating that the change trend is consistent with the blade damage rules. • A novel blade tip timing signal analysis method for low-speed blades. • Build an equivalent cantilever beam model of flue gas turbine blades. • Finite element modeling of a FGT blade to study the damage characteristics. [ABSTRACT FROM AUTHOR]

• Prefabricated enclosure wall panel using date palm midribs stud frame without wood. • Panel consists of 2 compact latticed faces over latticed studs frame with braces. • Composite I-beam action achieved by orthogonal faces lattices for dual stiffness. • Full-scale panel built by craftsman shows high sturdiness, strength and workability. • Finite Element Method analysis safe at allowable axial and transverse loads of SIP. Despite the environmental and economic benefits of prefabrication, its applications in Egypt remain limited due to the lack of trained builders and manufacturers. However, prefabrication is actively adopted in traditional date palm midribs handicrafts industries such as furniture and light partitions. This paper launches novel versatile utilization to revive market of date palm midribs industry. Innovated date palm midribs-based prefabricated enclosure wall panel, ModPalma, is a stud frame panel made entirely from midribs without supporting timber frame. Conceptualization of ModPalma was conducted through reflecting design fundamentals of lignocellulose-based commercial wall panels on traditional prefabrication techniques employed by common craftsmen. Constructional efficiency was assessed by building a full-size panel and Finite Element Method structural analysis of the executed details. The completed free-standing panel, built by craftsman with usual tools, indicated the high sturdiness, durability, workability and coherence of the design. The digital structural analysis showed that design was safe under loads exceeding allowable axial and transverse loads of standard Structural Insulated panels. Further research is to address enhancing the panel's structural and thermal performances, as well as investigating economic feasibility and marketing strategies needed to reintroduce ModPalma as cost-efficient and clever alternative to conventional wall panels. [ABSTRACT FROM AUTHOR]

• A lightweight vertical lathe with an innovative steel–polymer concrete frame is presented. • A design methodology based on relative tool-workpiece frequency response functions is proposed. • A finite element modeling methodology of a machine tool with a steel–polymer concrete frame is proposed. The paper presents the process of designing a lightweight vertical lathe with a steel–polymer frame. The purpose of using such a frame was to increase the stability of machining. As part of the study presented in this paper, polymer concrete was developed to provide a significant increase in the damping of steel structures (increase in the modal damping ratio for a steel beam by 239% and 81% reduction in the amplitude of the receptance function for the dominant resonance). Finite element models of lathes with steel–polymer concrete frame were built in three variants differing in polymer concrete filling distribution. Vulnerability of the machine tool variants to regenerative chatter instability was evaluated using frequency response functions calculated at tool-workpiece contact point. On the basis of the solution guaranteeing the highest stability of machining, a prototype lathe was built, subjecting model to experimental verification. The prototype lathe was characterized by up to 83% (on average 55%) reduction of relative tool-workpiece frequency response functions amplitudes, compared to steel variant. [ABSTRACT FROM AUTHOR]

When partial and/or non-retentive preparation, such as those for occlusal veneers, is indicated, a proper and stable adhesion is essential. Therefore, the aim of this in vitro study was to evaluate the effect of loss of adhesion in different regions of the bonding interface on the fatigue behavior of simplified lithium disilicate restorations. For this, lithium disilicate (IPS e.max CAD) discs (1 mm thick and Ø = 10 mm) were fabricated, polished with #400-, #600-, #1200-grit silicon carbide (SiC) papers, and crystallized. As substrate, fiber-reinforced resin epoxy discs (2.5 mm thick and Ø = 10 mm) were fabricated and polished with #600-grit SiC paper. The ceramic bonding surface was treated with 5% hydrofluoric acid and a silane-containing primer (Monobond N), while the substrate was etched with 10% hydrofluoric acid followed by the application of the bonding system primers (Primer A + B). A lacquer (nail polish) was used to simulate the loss of adhesion in specific areas according to the study design to compose the testing groups: bonded (control; did not received nail polish application); – non-bonded (loss of adhesion in the whole specimen area); – margin (loss of adhesion in the ceramic margin); – center (loss of adhesion in the ceramic central area). The adhesive area of partially bonded groups was 50% of the adhesive surface. Then, the discs (n = 12) were bonded to the respective substrate using a resin cement (Multilink N), light-cured, water-stored for 90 days, and subjected to thermocycling (25,000 cycles, 5° to 55 °C) before testing. A cyclic fatigue test was run (20 Hz, initial load of 200 N for 5000 cycles, 50 N step size for 10,000 cycles each until specimen failure), and the fatigue failure load and number of cycles for failure were recorded. As complementary analysis, finite element analysis (FEA) and scanning electron microscopy analysis were performed. Kaplan-Meier log-rank (Mantel-Cox) was conducted for survival analysis. The results showed that as the loss of adhesion reaches the central area, the worse is the fatigue behavior and the higher is the stress peak concentration in the ceramic bonding surface. The bonded specimens presented better fatigue behavior and stress distribution compared to the others. In conclusion in a non-retentive preparation situation, proper adhesion is a must for the restoration fatigue behavior even after aging; while the loss of adhesion reaches central areas the mechanical functioning is compromised. • The fully bonded scenario promotes better fatigue behavior and stress distribution. • The loss of adhesion in restoration's central areas compromises the mechanical performance. • Stress peaks are higher in adhesion-loss scenarios, regardless of the debonded region. [ABSTRACT FROM AUTHOR]

A finite element formulation is developed in this paper to analyze impact-induced waves in a rod collide with a striking mass. The formulation is established based on St. Venant's contact theory. Effects of mass ratios and boundary conditions, whether fixed, free, or elastic, are investigated. Both uniform rods and composite rods are considered. A shortcoming in traditional finite element models is to consider the rod and the struck mass as separate identities that gives inaccurate results for the discontinuity at the arrival of the impact wave. Instead, the proposed model considers the rod and the struck mass as one system that gives extremely accurate corresponding results. Wave propagation, transmission, and reflection from the constraint end and at the discontinuous interface are thoroughly analyzed. Succession collision that may occur between the struck mass and the rod is also investigated. Whenever it is possible, the finite element results are compared with analytical solutions. The analytical solutions are obtained with either the direct mode superposition method (DMSM) or wave theory. The proposed model can be used to model many systems that are subjected to longitudinal impact loadings and for crack detection. The model has the potential to be extended to perform simulation and analysis for many practical applications, like nanostructures under impact loads. [ABSTRACT FROM AUTHOR]

Structural Integrity and its response to the subjected cutting forces during machining, plays a vital role in the performance and the life of the machine tool. The machine tool must meet the demands of the stiffness and easy maintenance; in absence of this the desired machining accuracy during cutting operation is not achieved. While at the same time the machine structure cannot be made heavy which increases the manufacturing cost. The use of stiffener plates is a solution to this problem. However, the selection of the appropriate locations of stiffener plates based on only designer's design knowledge and experience may not lead to desired results. Hence, Structural analysis in conjunction with the structural optimization methods are employed for getting optimized structures. In this paper, experimental results obtained from the cutting force measuring machine which was manufactured for the experiment were used to analyse and optimize the structure of machine tool. The analysis and optimization were done with the help of Finite element methods technique (Optistruct solver) and modelling being done in Hypermesh. The optimized structure with stiffeners, led to the decrease in the maximum displacement thus increasing the stiffness of the machine structure while avoiding resonance. [ABSTRACT FROM AUTHOR]

Additive Manufacturing (AM) offers great potentialities in the medical sector, particularly when part customization is sought after. Maxillofacial surgery has to deal with complex bone fractures and facial reconstructions, hence the need of metallic prostheses to help in the process of bone growth and fracture healing. Commercial prostheses, even if available in different sizes, might not fit the patient's anatomy, and thus should be adapted directly in the operating room. This paper provides an insight on how AM approach, by designing and producing customized prosthesis from computer tomography scan data, can lead to predictable and reliable results reducing the stress on both surgeons and patients. [ABSTRACT FROM AUTHOR]

Finite element method (FEM) is widely used in machining processes as it can efficiently respond to the thermomechanical deformation and removal processes of materials. In this paper, FEM simulation analysis for laser-assisted machining (LAM) of Ti6Al4V alloy is carried out using two different modeling approaches: the sequentially coupled simulation (SCS) and the predefined fields coupled simulation (PFCS). The results of temperature, cutting force and chip morphology are obtained by these different approaches and verified by experiments. By analyzing the errors of the two approaches, the results show that the cutting force and chip morphology errors of the SCS method are 16.14% and 11.11%, respectively, while the errors of the PFCS method are 7.58% and 16.67%. However, neither of these approaches can fully simulate the complete LAM process. Therefore, a fully coupled simulation (FCS) approach needs to be developed to overcome the shortcomings of the above two methods. [ABSTRACT FROM AUTHOR]

This paper aims to carry out comprehensively the static bending, free vibration, and buckling analyses of two-layer FGM plates with shear connectors resting on elastic foundations, where two-layer FGM plates resting on Winker's-Pasternak elastic foundations taking into account relative sliding movements are analyzed by using the combination of Navier's solution and finite element method based on nth -order shear deformation plate theory. The plate is made up of two layers of FG materials joined by metal shear connectors. Lagrange and Hermitian shape functions are used to establish stiffness matrices, mass matrices, geometric stiffness matrices, and element force vectors. The suggested method and mechanical model are accurate when compared to the computed data from this research and reputable literature. The computed data accurately describes the mechanical response of the structure. Then a series of parameter investigations are conducted to capture the effects of the structure's geometrical and material features on the mechanical behavior of two-layer FG plates. The numerical results of this study may be utilized as a basis for future research, applications, and design of similar structures in mechanical and civil engineering practice. This is also a critical foundation for studying the dynamic behavior of structures with shear connectors. [ABSTRACT FROM AUTHOR]

The use of multidirectional composite-metal stacks employing glass fibre reinforced plastics (GFRP), is gaining traction in many industrial applications. However, finishing operations in these materials (e.g. drilling), often present problems such as delamination and burrs, which are mainly due to mechanical loads. This paper presents a hybrid approach to predicting drilling cutting forces based on mechanistic drilling models coupled with a 2D Finite Element Analysis (FEA). A comprehensive mechanical characterization of the GFRP that was used, to validate the new material constitutive model of the composite was carried out, and an accurate prediction of cutting forces was obtained. [ABSTRACT FROM AUTHOR]

Double-sided incremental forming (DSIF) is a die-less sheet metal forming process capable of fabricating complex parts. The flexibility of DSIF can be used for in-situ mechanical properties alteration, e.g., by controlling deformation-induced martensite transformation of austenitic stainless steels. In this paper, SS304L is deformed using DSIF at three different cooling conditions and two different tool paths to affect the martensite transformation. Additionally, finite element analyses were used to understand the effect of tool paths on springback and plastic strain. Implementing a reforming tool path at the lowest achievable temperature resulted in a martensite volume fraction as high as 95%. [ABSTRACT FROM AUTHOR]

This paper introduces a multi-objective design mechanism to minimize both the initial and running costs of industrial robot arms. The goal of the design problem is to decide the type of material and physical dimensions of the robot arm to withstand high loads at vulnerable locations using stress analysis. Additionally, it selects the material architecture for the robot links based on a vibration analysis to avoid robot failure at or close to the resonance frequency. Hence, a set of design equations based on stress analysis are developed using analytical approaches while the findings are supported by finite element simulations in ANSYS. These decide the type of material, cross-section area, factor of safety (FoS), and maximum deflection of the robot links in terms of the mass-loads. Moreover, the vibration analysis is conducted to enhance the dynamic characteristics of the robot arm. Therefore, the excitation frequency is modified by changing the mass and the robot segment-material to evade working at the natural frequency. Modal analysis is conducted using ANSYS to identify the fundamental frequencies and their modal shapes. Then, a material selection mechanism based on finite element analysis is considered to allow a safe frequency operation range for the robot arm. A customized robot arm structure that combines Magnesium and Aluminum alloy with highly improved FoS and minimizes the initial and operating costs is proposed. In addition to the body structure of the robot arm, the influence of the reducers and motors on the stiffness and vibration of the robot arm is presented. Finally, the motion of the robot arm is optimized using a Genetic Algorithm subject to a set of boundary conditions imposed by the desired mission. The effect of rotation angle value in the power consumption is presented. The coefficients of a developed angular displacement function are optimized to ensure minimum power consumption during the robot missions. [ABSTRACT FROM AUTHOR]

Stick-slip vibration is a common phenomenon met in oil gas drilling, especially in the complex trajectory wells such as highly-deviated wells, it will cause the earlier failure of BHA (bottom hole assembly) and lower drilling efficiency. In this present paper, a finite element model of highly-deviated well, which consists of a drill string system, a borehole, a PDC bit (Polycrystalline Diamond Compact bit) and a rock model, is carried out to investigate the stick–slip vibration behaviors of drill bit and BHA. Besides, the torsional impact drilling method is proposed in the context to control the stick–slip vibration of BHA. The research results show that, the phenomenon of stick–slip vibration of BHA gradually weaken and disappear with the distance from the drill bit increases, and the stick–slip vibration mainly occurs at the BHA which near drill bit. The high frequency torsional impact drilling method can reduce the resistance torque of the bit by 34.71%, and increase the drilling depth by about 58.28%. It can effectively improve the drilling efficiency of the bit, making the rotation of drill bit becomes relatively more stable, and reducing or even eliminating the stick–slip vibration. These results lead to an enhanced understanding of stick–slip vibration behaviors of drill bit and BHA in highly-deviated wells, and provide the basis for improving the drilling efficiency. [ABSTRACT FROM AUTHOR]

The paper addresses the effects of high-order space harmonics on the steady-state performance of five-phase induction machines operating under unbalance. We show that the airgap harmonic fields with orders higher than three, although usually disregarded, can produce a significant increase in the torque pulsation and in the Joule losses. We propose a model based on symmetric components which is used to demonstrate that the field produced by each rotor harmonic current is related to two stator sequence currents. Further, the proposed model allows determining additional losses and harmonic torques produced by airgap harmonic fields with orders higher than three, which up to now have not been addressed elsewhere. As a case study, we applied the model to two five-phase induction machines with different designs and assessed the influence of high space harmonics under operation at steady state with one open phase in the stator. The model has been validated by comparing analytical results with results obtained through finite element analysis. Finally, the model validation was also based on experimental results obtained from tests with two prototypes under many different conditions. • We introduce a new model of five-phase induction machines including space harmonics. • The model describes the steady-state behavior of machines operating under fault. • The model allows estimating joule losses and torque pulsation due to space harmonics. • The validation of the model is based on fem analysis and experimental results. [ABSTRACT FROM AUTHOR]

Ionisation process has been known to occur in soil, when earth electrodes are subjected under high impulse conditions. In this paper, experimental results on impulse response of various earth electrodes, namely a conventional copper rod electrode, and three steel rods which had been in a form of solid, hollow and hollow with stamping of star shaped, is presented. Impulse tests were performed for a range of voltage magnitudes up to 300 kV. Computation of electric field is carried out with Finite Element Method (FEM) to obtain its profile, and determine the electric field values produced for each rod electrodes and peak currents. Experimental results show that little difference in its impulse resistance with increasing current magnitudes in these electrodes, which could be due to the critical electric value, E c of the soil, and electric field of the rod electrode, which balances up its ionisation levels. [ABSTRACT FROM AUTHOR]

This paper presents a towards support-free design method for 3D printing (3DP) of thin-walled composite based on stratified manufacturability reinforcement (SMR). The thickness classification is carried out on manifold structure to describe probability distribution via probabilistic statistical approaches. The fundamentals of composite materials for functional requirements are introduced for hereafter transient thermal structure coupling calculation. Afterwards, to accomplish 3DP electromechanical servo motion, a mechanical equipment, namely dexterous robot with multi-axis degrees of freedom (DOFs) platform is schematically implemented. Thereout, the towards support-free design model is established likewise at different stratifications, by increasing the DOFs and reachable posture space, for the sake of support diminution. The lightweight ribbed specimens are taken as numerical examples to minimize the support quantitatively of each stratified layer, by investigating the effect of density and accessible workspace on external support amount. The temperature, deformation of both noncomposite and composite during 3DP are compared so as to confirm the manufacturability using Finite element analysis (FEA). The physical experiment is conducted with emphasis on infrared temperature distribution, tensile strength and non-contact optical profilometer where the external support can be evaluated quantitatively by electronic weighing balance. The test results proved that the proposed SMR method can improve the overall manufacturability, by virtue of towards support-free design, owing to considering both composite material properties and machine multi-axis dexterity, even under stringent multiple constraints of high strength and high precision. [ABSTRACT FROM AUTHOR]

Although the laser cladding technology is widely used in various fields, the laser cladding layer is prone to pores, inclusions and microcracks, severely limiting the popularization and application of this technology. High-frequency mechanical vibration can effectively reduce the micro defects in the cladding layer and strengthen the solidification structure of the cladding layer. In this paper, a laser cladding system for a disc laser assisted by ultrasonic vibration is built, and the dynamic response of ultrasonic vibration of the cladding experiment platform is tested. A finite element model of the dynamic response of the cladding experiment platform under ultrasonic vibration was established, and the difference of the vibration of the experimental platform substrate at different positions under the ultrasonic vibration was calculated. The internal amplitude of the substrate is differentiated in a hemispherical shape with the vibration source as the center and is distributed under the influence of ultrasonic vibration. On this basis, the phase field method was used to establish the ultrasonic-assisted disc laser cladding solidification model to obtain the dendrite growth state during the solidification process. The calculation reveals the change law of single crystal and polycrystalline solidification growth under the influence of ultrasonic amplitude at different substrate positions. Calculations show that ultrasonic vibration can effectively increase the growth rate of dendrites and promote the formation of secondary dendrite arms. The polycrystalline solidification growth model is closer to reality. The competitive growth of dendrites suppresses the growth of primary dendrites to a certain extent and affects the selective growth of dendrites. The results show that the larger the ultrasonic amplitude, the more rapid the formation of secondary dendrite arms. [ABSTRACT FROM AUTHOR]

This paper takes the electric vehicle with HV battery traction which has achieved the "five-star" result of CNCAP as the research object, and uses HyperMesh and LS-DYNA to establish a lateral impact finite element model for simulation to verify the performance of this vehicle in C-IASI. In order to improve the performance of the side structure, the structure is optimized by upgrading the materials of key components, optimizing the key force transmission path and filling the cavity in the key deformation area with polymer structural stiffeners. According to the optimization scheme, the finite element model is established and calculated. The results show that the optimization scheme can effectively solve the problem of excessive intrusion and intrusion speed of the inner plate of the B-pillar in side impact, and improve the deformation mode of the B-pillar at the same time, improve the side impact safety performance of the vehicle, meet the requirements of "GOOD", and provide a reference for the solution of similar problems of subsequent related vehicles. [ABSTRACT FROM AUTHOR]

The additive manufacturing of continuous carbon fibre reinforced composite allows the fabrication of stiff and light components. The mechanical properties of such materials can be comparable to Aluminium alloys' properties. However, it remains difficult for designers to identify the optimal fibre routing solutions to achieve the optimal performance for a component since there are set of printing parameters on fibre routing, such as fibre deposition angles in layer, number of concentric fibres and fibre layering sequence. In addition, there is a lack of numerical simulation tools for composite printing to support the decision making on fibre routing configuration. As a preliminary step, this paper presents an experimental investigation on the impacts of routing strategies on the component's mechanical properties so as to identify the key factors that will be used for the development of a simulation-driven optimization tool for fibre routing in composite printing. [ABSTRACT FROM AUTHOR]

Breast cancer is one of the most common women's cancers, so an available diagnostic modality, particularly non-invasive, is important. Infrared thermography (IRT) is a supporting diagnostic modality. Until now, many finite element methods (FEM) numerical models have been constructed to evaluate IRT's diagnostic value and to relate breast skin temperature characteristics with breast structural disorder presence, particularly to distinguish between cancerous types and normal structures. However, most of the models were not based on any clinical data, except for several papers based on clinical magnetic resonance imaging (MRI) data, wherein a three-dimensional (3D) breast model was studied. In our paper, we propose a very simplified numerical two-dimensional FEM model constructed based on clinical ultrasound data of breasts, which is much cheaper and available in real-time as opposed to MRI data. We show that our numerical simulations enabled us to distinguish between types of healthy breasts in agreement with the clinical classification and with thermographic results. The numerical breast models predicted the possibility of differentiation of cancerous breasts from healthy breasts by significantly different skin temperature variation ranges. The thermal variations of cancerous breasts were in the range of 0.5 °C–3.0 °C depending on the distance of the tumor from the skin surface, its size, and the cancer type. The proposed model, due to its simplicity and the fact that it was constructed based on clinical ultrasonographic data, can compete with the more sophisticated 3D models based on MRI. [ABSTRACT FROM AUTHOR]

In the present paper, the combination of mixed interpolation of tensorial components technique of triangular elements (MITC3) based upon the first-order shear deformation theory (FSDT) is developed to research the free and forced vibration of the unsymmetrical functionally graded porous (UFGP) folded sandwich plates. The MITC3 element still uses the triangular mesh and avoids the shear-locking phenomena that occur when using the classical triangular elements. Based on the basic formula of the MITC3 element for analyzing plates, the twisted angle (φ z) is added to the node displacement vector to solve for folded plates. Material properties of folded sandwich plates are unsymmetric with an FGP core layer, a metal bottom layer, and a ceramic top layer. The motion equations for UFGP folded sandwich plates are derived from Hamilton's principle. Some examples are conducted to verify the accuracy and reliability of the present method. Then, the new numerical results on the free and forced vibrations of UFGP folded sandwich plates are provided. [ABSTRACT FROM AUTHOR]

In ecology, Species Distribution Models (SDMs) are a statistical tool whose use has expanded considerably over the last two decades. As their use has grown, so has the complexity of the data analysed and the structures of the models used. This has led to the development of various tools to facilitate the incorporation and use of these new data and statistical methodologies, mostly embodied in new R packages and Shiny applications that allow different types of SDMs to be solved. However, the Integrated Nested Laplace Approximation (INLA) approach, which has become increasingly popular in the field of ecological sciences, has not yet been integrated into an application that can synthesise the complexity of its code into a user-friendly interface for continuous spatial modelling. To overcome this shortcoming, we present in this paper a novel application, called BAYSPINS (BAYesian SPatial INla for SDMs), which allows the use of INLA for those who are not very experienced, or for those who are experienced and prefer a tool that allows them to carry out an initial analysis quickly, avoiding the process of writing code. BAYSPINS allows both geostatistical and preferential modelling, as well as a mixture of the two. It integrates the complex and hard coded SPDE-FEM (Stochastic Partial Differential Equation, along with the Finite Elements Method) approach to perform continuous spatial analysis with a visual interface. It also allows the use of default settings that automate the process or the customisation of a large number of elements that drive the modelling process. In this way, quick initial evaluations or more rigorous studies of the data provided by the user can be carried out, depending on the user's skill and understanding of the fundamentals underpinning the application. [ABSTRACT FROM AUTHOR]

The Finite Element (FE) methods for biomechanical analysis involving implant design and subject parameters for musculoskeletal applications are extensively reported in literature. Such an approach is manually intensive and computationally expensive with longer simulations times. Although Artificial Intelligence (AI) based approaches are implemented to a limited extent in biomechanics, such approaches to predict bone strain in acetabulum of a hip joint, are hardly explored. In this context, the primary objective of this paper is to evaluate machine learning (ML) models in tandem with high-fidelity FEA data for the accelerated prediction of the biomechanical response in the acetabulum of the human hip joint, during the walking gait. The parameters used in the FEA study included the subject weight, number and distribution of fins on the periphery of the acetabular shell, bone condition and phases of the gait cycle. The biomechanical response has also been evaluated using three different acetabular liners, including pre-clinically validated HDPE-20% HA-20% Al 2 O 3 , highly-crosslinked ultrahigh molecular weight polyethylene (HC-UHMWPE) and ZrO 2 -toughened Al 2 O 3 (ZTA). Such parametric variation in FEA analysis, involving 26 variables and a full factorial design resulted in 10,752 datasets for spatially varying bone strains. The bone condition, as opposed to subject weight, was found to play a statistically significant role in determining the strain response in the periprosthetic bone of the acetabulum. While utilising hyperparameter tuning, K-fold cross validation and statistical learning approaches, a number of ML models were trained on the FEA dataset, and the Random Forest model performed the best with a coefficient of determination (R2) value of 0.99/0.97 and Root Mean Square Error (RMSE) of 0.02/0.01 on the training/test dataset. Taken together, this study establishes the potential of ML approach as a fast surrogate of FEA for implant biomechanics analysis, in less than a minute. [Display omitted] [ABSTRACT FROM AUTHOR]

Magnesium/Ceria nanocomposites (Mg/xCeO 2 NCs (x = 0.5 %, 1 % and 1.5 %)) prepared by using powder metallurgy and microwave sintering method are assessed for their corrosion rate for a period of 28 days. As per the immersion tests results, the addition of ceria nanoparticles to pure Mg, brought about a noteworthy improvement to corrosion resistance. A corrosion rate of approximately 0.84 mm/year for Mg/0.5CeO 2 and 0.99 mm/year for Mg/1.0CeO 2 nanocomposites were observed. Another aspect of the study involves employing the simulation method i.e. finite element analysis (FEA) to compare the stress distribution in magnesium-ceria nanocomposite based screws and circular bars especially for Mg/0.5CeO 2 and Mg/1.0CeO 2. Further, the simulation also gives a perception of the impact of masticatory forces, the biting force and shear stress exerted on the Mg/0.5CeO 2 and Mg/1.0CeO 2 based screws. The simulations results show that the screws showed an acceptable level of stresses for a biting force up to 300 N. The circular bar as well kept its stresses at acceptable levels for the same load of 300N. The shear stress results indicated that a biting force up to 602 N can be safely absorbed by Mg/0.5CeO 2 screw. The comprehensive approach allows for a better understanding of the corrosion behavior, stress distribution, and mechanical properties of the Mg/CeO 2 nanocomposites, enabling the development of effective temporary implants for craniofacial trauma fixation that can withstand normal physiological forces during mastication. The study reported in this paper aims to target Mg/xCeO 2 NCs for temporary implants for craniofacial trauma fixation. [Display omitted] • Lightweight Mg/REOs nanocomposites (1.74–1.80 g/cc) are synthesized. • Corrosion resistance is enhanced when REOs nanoparticles are added to pure Mg. • This material when implemented as a 2 mm screw, can withstand biting force of 602N. • Mg/REOs screw and plate implants are viable choice for dental prosthesis. [ABSTRACT FROM AUTHOR]

The main cause of failure in bonded ceramic restorations is material fracture due to excessive stress concentration at the base of the prosthesis. The design of restorative functionally graded materials (FGM) could represent a major advance in dissipating mechanical stresses during occlusal contacts. The aim of this paper is to carry out a complete factorial design of finite element analyses to optimize a multilayer FGM introduced at the bottom of an overlay prosthesis. The number and thickness of layers vary within a spectrum compatible with ceramic shaping processes whereas Young's moduli variations are set in the range of dental tissues. For a 1.5-mm thick prosthesis, the optimal FGM configuration appears to be a 5 layers of 0.2 mm thickness with a linear distribution of Young's modulus from 30 to 70 GPa. This configuration was implemented in a 3D model of a restored tooth with realistic geometry to validate the proof-of-concept. [ABSTRACT FROM AUTHOR]

Based on the unique monoclinic characteristics of the plastic deformation of the tetra-missing rib honeycomb, the symmetrical design of the whole and subunits of the tetra-missing rib honeycomb was carried out in this paper, and two new types of tetra-missing rib honeycomb with symmetrical structural characteristics were obtained. First, quasi-static compression was performed on three structures, including a conventional tetra-missing rib honeycomb, and the experimental results showed that both symmetrical designs could effectively improve the plastic deformation of the conventional tetra-missing rib honeycomb. At the same time, round holes were introduced into the three honeycomb structures, and the mechanical properties and deformation modes of the three structures under quasi-static loads were explored. The results of two sets of experiments were compared, and it was found that the introduction of round holes could improve the structural stiffness of the honeycomb. Second, Abaqus/Explicit was used to construct a finite element numerical model in the later stage, and the accuracy of the model was verified. The number of honeycomb cells was determined for the three honeycomb structures, and finally, the dynamic Poisson's ratio of the honeycomb structure in plastic deformation was determined, and the negative Poisson's ratio (NPR) effect of the three honeycombs was compared. [ABSTRACT FROM AUTHOR]

The paper concerns the numerical design of novel three-dimensional titanium scaffolds with complex open-porous structures and desired mechanical properties for the Powder Bed Fusion using Laser Beam (PBF-LB). The 60 structures with a broad range of porosity (38–78%), strut diameters (0.70–1.15 mm), and coefficients of pore volume variation, CV(V p), 0.35–5.35, were designed using the Laguerre-Voronoi tessellations (LVT). Their Young's moduli and Poisson's ratios were calculated using Finite Element Model (FEM) simulations. The experimental verification was performed on the representative designs additively manufactured (AM) from commercially pure titanium (CP Ti) which, after chemical polishing, were subjected to uniaxial compression tests. Scanning Electron Microscopy (SEM) observations and microtomography (μ-CT) confirmed the removal of the support structures and unmelted powder particles. PBF-LB structures after chemical polishing were in close agreement with the CAD models' dimensions having 4–12% more volume. The computational and experimental results show that elastic properties were predicted in very close agreement for the low CV(V p), and with even 30–40% discrepancies for CV(V p) higher than 4.0, mainly due to PBF-LB scaffold architecture drawbacks rather than CAD inaccuracy. Our research demonstrates the possibility of designing the open-porous scaffolds with pore volume diversity and tuning their elastic properties for biomedical applications. [Display omitted] • Open‑porous biomedical scaffolds, varied in pore size distributions, were designed via Laguerre‑Voronoi Tessellations. • Elastic properties (Young's moduli and Poisson's ratios) were simulated using Finite Element Method (FEM). • Selected structures were fabricated from titanium using Powder Bed Fusion using Laser Beam (PBF‑LB). • Chemical polishing effect was examined Scanning Electron Microscopy (SEM) observations and microtomography (µ CT). • Simulated elastic properties have been experimentally validated for selected PBF‑LB samples. [ABSTRACT FROM AUTHOR]

The strength of concrete after its casting increases with time up to a certain limit due to continuous hydration reactions in the cement matrix. To measure the rate of strength development and ultimate capacity of concrete, a novel health monitoring method using Reusable smart bolt (RSB) piezoelectric sensor is proposed in the present paper. The smart piezoelectric Lead zirconate titanate (PZT) patch-based Electro-mechanical impedance (EMI) and Wave propagation (WP) techniques are utilised for accessing the health of concrete at 1, 3, 5, 7, 14, 21 & 28 days of concrete hydration. Firstly, the PZT patch-based sensing capabilities are validated with the experimental results from literature by modelling concrete cube for EMI and beam for WP results. Then, a total of 31 finite element models of concrete cubes having different RSB configurations were taken into consideration for sensor design and optimization. In EMI technique, the shifting of conductance signatures and relative resonance frequency are measured, whereas in WP technique, the shift of P-wave velocity peaks between actuator and sensor is estimated for all the models. The sensitivity of outputs is measured by plotting statistical Root mean square deviation (RMSD) index which proven the efficacy of employing RSB sensors for monitoring concrete strength-development during early-hydration ages with good correlations. Overall, the EMI-identified RMSD plotted for conductance shows 327 % more sensitivity than WP-identified relative change of P-wave velocity in monitoring concrete strength development using RSB sensors. [ABSTRACT FROM AUTHOR]

The application of the 3D printing and additive manufacturing in making medical devices have become widespread in the last decades as the opportunity of the technology is rapidly growing. Notably, the Fused Deposition Modeling (FDM) in 3D printing technique has been applied to develop the ankle-foot orthosis (AFO) with different materials and composites. This paper presents a new design and simulation results of a novel orthosis using Carbon Fiber Reinforced Polymer (CFRP). The orthosis for ankle-foot is designed for rehabilitation of the patient from the foot drop disease. The orthosis' shape is modelled to support the backside of the calf. It contributes to the maintenance of the gait cycle. In this paper, two different models of the AFO are compared, namely articulated and non-articulated. The finite-element analysis is done using the ANSYS software, and the results for equivalent Von-Mises stress as well as total deformation are observed and analyzed. Various materials are applied during the numerical analysis, as well as their combinations are tested. [ABSTRACT FROM AUTHOR]