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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]

This paper presents the process of conducting the structural analysis of AlAinSat-1 CubeSat through a numerical solution using Siemens NX. AlAinSat-1 is a 3U remote-sensing CubeSat carrying two earth observation payloads. The CubeSat is scheduled for launch on SpaceX Falcon 9 rocket. To ensure the success of the mission and its ability to withstand the launch environment, several scenarios should be analyzed. For AlAinSat-1 model the finite element analysis (FEA) method is used, and four types of structural analyses are considered: modal, quasi-static, buckling, and random vibration analyses. The workflow cycle includes idealizing, meshing, assembling, applying connections and boundary conditions, and eventually running the simulation utilizing the Siemens Nastran solver. The simulation results of all analysis types indicate that the model can safely withstand the loads exerted during launch. Also, the numerical results of the Command and Data Handling Subsystem (CDHS) module of AlAinSat-1 are experimentally validated through a vibration test conducted using an LV8 shaker system. The module successfully passed the test based on the test success criteria provided by the launcher. [ABSTRACT FROM AUTHOR]

This paper discusses the selection of an interior permanent magnet synchronous machine and converter for a 100V-200V DC, 100-400 Hz, 150-175 Nm, 30kW-100kW, 1550-4100 rpm electrical vehicle engine alternator. The electrical vehicle engine application requirements are outlined including the engine coupling configuration. Then the characteristics of different machines and their converters are compared through a competitive trade-off study framed by the alternator requirements; direct-drive induction, variable-reluctance, surface permanent magnet synchronous machine, and interior permanent magnet synchronous machine are all considered. The results of the study indicate that the interior permanent magnet synchronous machine is a potentially superior candidate, and so this machine is selected for further investigation. The preliminary findings are described, and the paper concludes with a discussion of current work addressing analytic design. [ABSTRACT FROM AUTHOR]

This paper presents an assessment study of traffic-induced ground vibrations and their effects on masonry-type historic structures in Ayutthaya Historical Park, a UNESCO World Heritage Site in Thailand. The first objective is to propose a practical prediction of the attenuation rate of vibration for risk management of the monuments located along roadsides in the city. The attenuation of vibration waves traveling from traffic sources and the intensity of ground vibrations were determined by in situ vibration measurement. The results from the investigations in the Ayutthaya area were compared with those obtained from other sites having different characteristics of subsoil classified by the average shear wave velocity (Vs). It was found that the attenuation rates at a long distance from the source tend to be dependent on soil property in terms of Vs of subsoils. The attenuation curves derived from the regression analysis are proposed for risk management from the vibration of the heritage site. The second objective is to assess the effects of traffic vibrations on historic structures. The highest amplitude observed in Ayutthaya was within the recommended vibration criteria for historic buildings. In addition, finite element analysis of a 3D stupa model revealed that the stresses resulting from the ground vibration records induced by traffic was lower than the strength of ancient brick and mortar. [ABSTRACT FROM AUTHOR]

Spur gear, helical gear, worm gear, and bevel gear are all important components in industrial applications such as vehicles, pushes, conveyors, elevators, bowl mill, rolling mills, ribbon blender, machine tools, aeroplanes, and windmills. When various types of defects, such as wear, tooth breakage, corrosion, and scratches on bearings, appear in gearboxes, normal machine function may be abruptly terminated. As a result, output and dependability suffer. As a result, several quality tracking and evaluation approaches have been adopted by companies. Finite element analysis (FEA) is one of the approaches. This research paper presents the FEA of a ribbon blender worm gear pair by using Ansys 18.0 to identify the weak gear of the worm gear pair, natural frequency, and deformation. Proe-5 utilized for creation of three-dimensional geometry of threaded worm and toothed worm wheels, as well as other related elements such as shafts and bearings. Steel is used for the worm, shaft, and bearing, whereas bronze is used for the worm wheel. Ansys 18.0 is implemented to carry out worm gear pair model analysis. The results demonstrate that the worm wheel had the most deformation when compared to the worm, and that the natural frequency is greater than the operational frequency of the worm gear pair. The findings of the research study, worm wheel deteriorate early than worm, model analysis plays a significant role in vibration monitoring of worm gear pair, and this work is valuable for further fault analysis of ribbon blender worm gearbox utilizing vibration response. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper investigates a new external fixator system for treating finger contractures. This innovative system is electric and user-friendly, providing precise readings of the angles of diseased finger joints. Accurate measurements of the angles of the diseased finger joints can assist therapists and patients during rehabilitation procedures. The fixator consists of ten parts assembled using polyether-ether-ketone (PEEK) for the plastic components and stainless steel for the metal components. The design model was engineered, drawn, and analyzed using SolidWorks Computer-Aided Design software. The verification process utilizes finite element analysis to demonstrate that the maximum stress was lower than the yield strength of the chosen materials. As a result, the new device design is robust and stable enough to withstand the anticipated loading conditions of human fingers. Subsequently, a prototype was fabricated using advanced additive manufacturing technology, specifically fused deposition modeling (FDM). The proposed fixator is simple to control, reliable, easy to use, and reproducible. It enables device users to exercise their finger joints throughout the day without requiring the assistance of specialists. [ABSTRACT FROM AUTHOR]

High-fidelity simulation tools have significant potential to support composite aircraft sustainment, though further study is required on incorporating the complex impact damage field. In this paper, compressive residual strength assessment is investigated using the high-fidelity computational tool BSAMTM. The experimental impact damage was mapped and modelled at a high-fidelity level, which included ply-by-ply definition of the geometry of the impact indentation, fibre fracture in the plies and delamination in ply interfaces. It was shown that applying a small lateral displacement or 'pseudo-impact' step was highly effective in generating matrix cracks in the impact region, which provided a suitably realistic representation of the interconnected damage map through-the-thickness. It was found that inclusion of all damage modes in the post-image damage map at a high-fidelity definition was essential due to the strong degree of interaction between damage modes. The results support improved sustainment of defence platforms, through enhanced predictive capability and understanding. [ABSTRACT FROM AUTHOR]

Metastases increase the risk of fracture when affecting the femur. Consequently, clinicians need to know if the patient's femur can withstand the stress of daily activities. The current tools used in clinics are not sufficiently precise. A new method, the CT-scan-based finite element analysis, gives good predictive results. However, none of the existing models were tested for reproducibility. This is a critical issue to address in order to apply the technique on a large cohort around the world to help evaluate bone metastatic fracture risk in patients. The aim of this study is then to evaluate 1) the reproducibility 2) the transposition of the reproduced model to another dataset and 3) the global sensitivity of one of the most promising models of the literature (original model). The model was reproduced based on the paper describing it and discussion with authors to avoid reproduction errors. The reproducibility was evaluated by comparing the results given in the original model by the original first team (Leuven, Belgium) and the reproduced model made by another team (Lyon, France) on the same dataset of CT-scans of ex vivo femurs. The transposition of the model was evaluated by comparing the results of the reproduced model on two different datasets. The global sensitivity analysis was done by using the Morris method and evaluates the influence of the density calibration coefficient, the segmentation, the orientations and the length of the femur. The original and reproduced models are highly correlated (r2 = 0.95), even though the reproduced model gives systematically higher failure loads. When using the reproduced model on another dataset, predictions are less accurate (r2 with the experimental failure load decreases, errors increase). The global sensitivity analysis showed high influence of the density calibration coefficient (mean variation of failure load of 84 %) and non-negligible influence of the segmentation, orientation and length of the femur (mean variation of failure load between 7 and 10 %). This study showed that, although being validated, the reproduced model underperformed when using another dataset. The difference in performance depending on the dataset is commonly the cause of overfitting when creating the model. However, the dataset used in the original paper (Sas et al., 2020a) and the Leuven's dataset gave similar performance, which indicates a lesser probability for the overfitting cause. Also, the model is highly sensitive to density parameters and automation of measurement may minimize the uncertainty on failure load. An uncertainty propagation analysis would give the actual precision of such model and improve our understanding of its behavior and is part of future work. [Display omitted] • Reproducibility of the femur failure load model is validated. • Transposition of the femur model shows different performances on two datasets. • Sensitivity of the model with respect to density-based parameters is high. • Sensitivity with respect to segmentation, orientation and femur length is not negligible. [ABSTRACT FROM AUTHOR]

The paper presents the study and analysis with finite elements of the hook of a hoist, as well as the load capacity of the hook varying the cross-sections. The selected sections were constant over time and then the sizes of two different sections were changed. The hoist hook is modelled using SOLIDWORKS software. Von Mises stress analyses were performed. To validate the stress distribution model for its correctness, he used the theory of curved beams. The obtained results were compared with those determined by analytical calculation and it was found that the deviations are at least 5%. The finite element analysis method can be used for different material types and different loadings. [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]

Nuclear power plants have a very large catalog of regularly manipulated manual valves. To achieve the desired performance and operating margins, skilled technical staff use these valves to control, start, stop, regulate, and throttle the flow of various fluids through plant systems. Wireless valve position indication (VPI) sensor system technology would enable online monitoring of manual valve positions. Using additive manufacturing techniques, the wireless VPI sensor system is retrofitted onto existing manual valves using a sensor mounting unit (SMU). The structural stability of the retrofitted SMU is important for reliably measuring valve position with the wireless VPI sensor system. This paper presents the design, numerical modeling, and experimental validation of SMUs for rising stem gate and rising handle globe valves. Three types of materials, i.e., ULTEM 9085, chopped carbon fiber reinforced nylon, and continuous carbon fiber reinforced nylon, were used to three-dimensionally print the SMUs. The free vibration responses of these SMUs are presented in this paper. The results show how the choice of design, material, and other printer parameters impact SMU vibration responses, especially for the first and second eigenfrequencies. Next, performance of the SMUs is evaluated through both numerical and experimental vibration analysis, and then, the consistency of outcomes using each analysis type is presented. In terms of the stiffness-to-weight ratio and eigenfrequencies, the research shows the SMU printed with 5% continuous carbon fiber reinforced nylon fared significantly better than those printed from the other two materials. [ABSTRACT FROM AUTHOR]

A porous structure is widely used in additive manufacturing of orthopedic implants to reduce the stiffness mismatch between the implant and the bone. The development and improvement of porous structures for orthopedic implants is still a major challenge. It is essential to study mechanical properties of different porous structures and their relation to the deformation mechanism. In this paper, the relation between the deformation mechanism and the mechanical properties of Ti6Al4V triply periodic minimal surface (TPMS) structures, such as stretching-dominated IWP and bending-dominated gyroid structures, are investigated using the finite element analysis for uniform and density gradient scaffolds. The method for designing network-based and sheet-based TPMS structures is presented. The numerical results show that failure in the stretching-dominated structure (IWP) starts with buckling of the vertical struts, whereas failure in the bending-dominated structure (gyroid) occurs with the formation of the 45° shear band. The gyroid structure shows a higher shear modulus than the IWP structure. The numerical results exhibit good agreement with the previous experimental data for uniform and density gradient structures. Finally, the effect of the void defect on the elastic and shear moduli is evaluated. The results indicate that the elastic modulus of the bending-dominated structure shows a greater reduction in the presence of void defects than that of the stretching-dominated structure, and the shear modulus of the stretching-dominated structure is more sensitive to void defects than that of the bending-dominated structure. [ABSTRACT FROM AUTHOR]

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a new con guration of semi-supported steel plate shear wall to increase its efficiency. For this purpose, the infill steel plate is proposed to be trapezoidal instead of rectangular. In order to find the most efficient inclination angle of lateral sides, a numerical parametric study was conducted. Five different values of inclination angle including 60°C, 75°C, 90°C, 105°C, and 120°C were considered. Furthermore, two thicknesses of 1.75 and 2.00 mm were considered for steel plate. The area of steel plate was the same for all the models. The models were analyzed using finite element software ABAQUS.Both geometric and material nonlinearities were considered. In order to validate the finite element modeling, the available experimental results were used. According to the results of comparing the wall with the rectangular plate, the inclination angle of 60°C increased the ultimate lateral strength and stiffness of the 1.75 mm-thick wall by 46% and 66%, respectively. Furthermore, a simple approximate model was presented to calculate the load-deformation response of the proposed wall using SAP 2000 program. Despite the simplicity of the method, the results were in good agreement with the results of ABAQUS. [ABSTRACT FROM AUTHOR]

This paper presents the design, analysis and comparative study of three different configurations of Switched Reluctance Motor (SRM) suitable for In-wheel application in Electric Vehicles. C-core stator with dual rotor SRM, C-core stator with disk-type segmented rotor SRM and Dual gap inner segmented rotor SRM are designed and compared for the same stator/rotor pole, supply current, current density and outer diameter. The significant performance indices of an electric motor for an in-wheel application, such as torque ripple, torque per unit active weight and torque per unit active volume, are considered for analysis. 3D Finite Element Analysis (FEA) of the machines is performed using the software MagNet 7.5 due to the axial field distribution of the configurations. The best among the three configurations is fabricated and experimental results are presented. [ABSTRACT FROM AUTHOR]

Unlike traditional manipulators with high rigidity and limited degrees of freedom, pneumatic manipulators have significant superiorities such as flexibility, lightweight and cleanliness, and therefore, have been one of the most popular research directions in robotics. However, most existing pneumatic manipulators have disadvantages such as low rigidity and simple functionality. In order to make up for the shortcomings of existing pneumatic manipulators, this paper proposes a new pneumatic flexible manipulator inspired by the concept of origami, which realizes the combination and balance of flexibility and rigidity. Finite element analysis is conducted to study influences of the number of airbags, the angle of main beam, and the width of main beam on the performance of the flexible manipulator. The simulation results are utilized to optimize the structure of the flexible manipulator. A pneumatic control system is designed to realize the automatic control of the pneumatic flexible manipulator. At the same time, a prototype is 3D printed, the experimental platform for pneumatic deformation is built, and the verification experiments of the single-jaw manipulator and the three-jaw manipulator are completed. [ABSTRACT FROM AUTHOR]

Clamping fixtures are located in the accuracy path of the manufacturing system. Therefore, their dynamic behavior has a direct impact on the accuracy, quality and cost effectiveness of the machined workpieces. However, due to the assembled structures, the nonlinear dynamic contact behavior is significantly related to the stiffness and damping properties of the complete system. In order to precisely describe the nonlinear phenomena, e.g. microslip effects, the simulation requires more realistic friction models than the Coulomb contact law, which is widely used in FE software. This paper focuses on modeling the workpiece-fixture contact behavior based on experimental measurements. The normal contact was modeled using the constitutive model of Greenwood and Williamson. In tangential direction, the Iwan model was applied for the hysteresis loops with macroslip. Another model based on the Mindlin's approach fitted the loops without macroslip. Furthermore, a concept of optimizing the fixture layout by means of machine learning is presented. The intelligent combination of machine learning and finite element analysis in the design phase offers a great potential for improving the machining quality. [ABSTRACT FROM AUTHOR]

Joints are the key factors that determine the construction difficulty and structural safety of prefabricated steel structures. However, the existing prefabricated joints of square steel tube and H-shaped steel beam frame have few reference forms, and there are still a series of problems in practical engineering applications, such as construction difficulties and poor applicability. Therefore, a new type of column-column-beam joint with variable beam height and its construction scheme are designed in this paper. The joint is bolted rather than welded in the process of field prefabricated. It can solve the problem of vertical and horizontal connection of steel frame structure through one joint at the same time, thus effectively saving construction cost and ensuring construction quality. In addition, the detailed modeling and comprehensive mechanical properties analysis of the joint scheme are carried out in this paper. The ultimate bearing capacity, stiffness characteristics, failure modes and hysteretic behavior of joint schemes under low cyclic loading are also evaluated. [ABSTRACT FROM AUTHOR]

The design of foundations for buildings subjected to unload–reload cycles generate the need to understand the reloading effects in piles. Commonly, such foundations are found in unsaturated soils, which also requires considering the effects of matric suction. This paper investigates the effects of soil suction and reloading on the behaviour of piles from an experimental and numerical approach. A bored pile built on a tropical soil profile was subjected to a sequence of load tests, performed at different climate seasons. An average 85% decrease in soil suction was measured from the pile load test in the dry season to the test in the rainy one, which contributed to a reduction in the pile's ultimate axial load capacity and stiffness of around 50%. The unload–reload cycles caused an increase on the pile's ultimate load capacity between 7% and 9% and on the pile stiffness between 13% and 24%. [ABSTRACT FROM AUTHOR]

To achieve ever-increasing productivity requirements in serial production, while ensuring product quality and machining process stability, special workpiece specific fixtures are required. Designing such a device can be a very complex and demanding process, requiring a high level of experience and insight from the designer. The purpose of this work is to show the potential possibilities of applying modern software tools to the fixture design process in order to provide reliable part positioning and clamping, while lowering the experience level required on the designer's part. The example analysed in the paper shows how applying modern software can enable detailed fixture evaluation and process optimisation in the early stages of fixture design, significantly reducing the risks associated with the classical design process and provide a deeper insight into the behaviour of the fixturing system. [ABSTRACT FROM AUTHOR]

Transformers are one of the most important elements of electrical power systems. In several conditions, the same transformer is connected to many different networks with different voltage levels and the replacement of the transformer is one of the most difficult tasks for the power suppliers. Tap winding transformer can be used to overcome the problems of the variable primary or secondary voltages. However, tap winding positions and type significantly affect the overall leakage impedance and it is one of the major concerns for the tap winding transformer designers. In this paper, the tap winding transformer distance was optimized with additional tap winding on the high voltage winding side. To optimize and calculate the leakage impedance in the tap winding transformers with three different voltage levels, finite element analysis was used. The prototype tap winding transformer was manufactured with the help of the finite element method. The difference between the short-circuit experimental test and the finite element method result was less than 1%. The experimental results show that optimal calculation of the leakage impedance in the tap winding transformer can be achieved with help of the finite element analysis. [ABSTRACT FROM AUTHOR]

In the first two years of the Mechanical Engineering curriculum at The Citadel, students take a computer applications course related to programming and a separate course related to CAD modeling. Typical student feedback is very positive in the CAD course due to the hands-on nature and real world applications evident in the coursework, but students often struggle to appreciate the useful applications of programming, which leads to lower engagement in the course. In this paper, the authors present an independent study project that focuses on modifying an STL file in MATLAB to optimize its shape in response to applied forces, in an effort to bridge the gap between these software applications. Through this exercise, the student gained an understanding of data types, programming structures, algorithm development, and other coding best practices through a tangible, real-world application. The present paper will discuss the problem approach, a discussion of the applicable ABET outcomes to this project, as well as recommendations for adapting this independent study project into a course module. [ABSTRACT FROM AUTHOR]

This paper discusses a new method of simulating the fuel assembly duct-bowing reactivity coefficient for EBR-II run 138B. Quantification of the fuel assembly duct-bowing reactivity effect in liquid metal–cooled fast reactors has been a persistent problem since they were first designed and operated. Simulation of the duct-bowing reactivity effect is difficult because the level of detail required to simulate the effect has exceeded most modeling capabilities. The new method outlined in this paper utilizes the finite element analysis code ANSYS to analyze the thermal and structural components. The displacement of the fuel assembly duct due to thermal expansion and mechanical interaction was calculated by ANSYS using recorded EBR-II run 138B temperature and power boundary value data. The displacement values were incorporated into to a Monte Carlo model of EBR-II run 138B and keff was calculated. Multiple Monte Carlo calculations were performed with duct displacement values corresponding to different reactor temperatures. Using the calculated keff values associated with the different duct displacement results allowed calculation of the duct-bowing reactivity coefficient. The duct-bowing reactivity coefficient was calculated to be −14.5 × 10−4 $/°C/ ± 4.4%. [ABSTRACT FROM AUTHOR]

This paper takes a loess landslide in the south of Huxian County, Xi 'an City, Shanxi Province, China as the research object. The landslide is located at the northern foot of the Qinling Mountains. In the past few years, villagers have excavated a large amount of loess at the foot of the slope for road construction, which has greatly reduced the stability of the slope and posed a serious threat to the lives of residents near the landslide. The author made a systematic study of the landslide, carried out detailed engineering geological survey and mapping of the landslide, and carried out artificial rainfall test and pore water pressure test at the foot of the landslide. Based on the survey and rainfall test data, the stability of loess slope is calculated by using finite element numerical method, the mechanism model of slope deformation is established, and the formation process of slope deformation is analyzed. The experiment and numerical analysis show that the pore water pressure in slope is affected by rainfall intensity, rainfall time and soil thickness under artificial rainfall condition. Under the daily rainfall of 274mm and rainfall of more than 4 days, the maximum influence depth of pore pressure is 2.2m. During rainfall, the pore water pressure gauge shows obvious hysteresis, the hysteresis at 0.4m is 10h, and the hysteresis in the soil layer below is prolonged. According to the results of finite element stability calculation, the horizontal displacement ranges from the maximum value of 0.19m in the initial state to 4.7m at the end of 15 days of rainfall, indicating that the slope has slipped locally. The calculated time of slope failure is also estimated, which is basically consistent with the actual time of landslide. [ABSTRACT FROM AUTHOR]

Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tire recycling and reuse in North America and worldwide have increased considerably, with the aim of reducing the harmful effects of scrap tires on the environment. Accordingly, the use of tire derived aggregates (TDA) in civil engineering applications is on the rise at an unprecedented rate. In comparison to conventional backfill aggregates, TDA is an inexpensive, lightweight material that costs about 25% of the cost of conventional backfill. Thus, there is an increasing trend of using TDA under shallow foundations as a lightweight backfill alternative. However, limited information exists for the design of shallow foundations built on TDA. Hence, the main objective of this paper is to develop a simplified design procedure for shallow foundations built over a TDA layer. Rigorous finite element models were developed and validated using field tests results. Subsequently regression analyses were used to develop the proposed ultimate bearing capacity equation, taking into account the granular layer thickness, TDA layer thickness, footing width, footing shape, footing depth, and the allowable settlement. [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]

In the hip stem prostheses domain, stress shielding represents a major issue due to its potential implant loosening effect. This phenomenon occurs when the implant is much stiffer than the bone itself. A way to reduce this stiffness difference is to remove material from the implant. In addition, this solution leads to mass reduction of the implant, improving the patient quality of life. To insure the implant will withstand the loading, material must be distributed in a specific way. Bones use the same objectives of lightness and mechanical efficiency while using a minimal amount of material. In addition, these biological structures are well spread and reliable in living beings, especially in mammals and avian species. In this paper, a method bio-inspired by trabecular bone structure is proposed to remove material from parts considering their mechanical stress field. In Nature, trabecular bone is defined as a graded porous material with bone material locally oriented along the local stresses' direction. To mimic this natural behavior, the proposed method generates local porosities bio-inspired in position, shape, size and orientation. To evaluate the proposed method performance, experimental tests were carried out on a hip prosthesis stem. Test results demonstrated that the method can be used to reduce the stiffness of the prosthesis while withstanding the applied constrains. [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]

Current transformers reduce large current values to measurable current values in electrical systems and provide isolation of various measuring instruments and relays from the main electrical system. Voltage current transformers are produced according to the tests defined in national and international standards during the production phase. In order for the relays used for protection in electrical systems to work correctly, medium voltage current transformers must be within the verified operating range. For this reason, it becomes very important for current transformers to work correctly. In case the main current has a harmonic structure, the operating range of the protection type medium voltage current transformers can change significantly. In this paper, it the steady-state thermal performance behaviour in a medium voltage current transformer is studied and analysed. The study was carried out considering four different loads. The numerical results of the temperature distribution were obtained using a 2D finite element software package. The iron losses in the core region were calculated using the maximum flux density that was obtained with a 2D finite element software package. The numerical solutions were compared with measured experimental results that were obtained in tests. Some conclusions are remarked. [ABSTRACT FROM AUTHOR]

In this paper, numerical computations using PLAXIS 2D and 3D have been conducted to optimize a row of piles in cohesive-frictional slope stabilization. First, 2D parametric studies were performed to identify both the optimal location and length of the pile as well as the effect of pile head conditions. Next, more rigorous parametric studies taking account of the exact geometry was carried out using 3D analyses. According to the obtained results, the fixed pile head located at the slope middle better improves the stability and reduces the optimal length of the pile. Piles with free head contribute marginally to the increased factor of safety of cohesive-frictional slope. In 3D analyses, it is shown that spacing ratio beyond S/D = 4 (S: pile spacing, D: diameter of the pile) , the soil will flow between piles leading to a total vanish of the arching effect when S/D exceeds 12. Comparing the results, the limitation of 2D analysis for piled cohesive-frictional slope is highlighted. [ABSTRACT FROM AUTHOR]

Mattress plays an important role in the quality of human sleep, warp-knitted spacer fabric (WKSF) is a rather important mattress material, this paper explored the indentation state of WKSFs of 20 mm thickness and 0.12, 0.15, 0.18, and 0.25 mm spacer filaments under the action of curved surface pressure by using spherical compression tests and finite element simulations, with the combination of three-dimensional and non-uniform pressure characteristics exerted on the mattress by the human body when lying down. Tests and simulations analysis would be shown in four aspects: firstly, when the spherical indenter acts on the WKSFs, the compressive stress, Indentation Force Deflection (IFD) and support factor (SF) of the WKSFs increase as the spacer filament fineness increases; secondly, the compression depth of WKSFs should be controlled within 40% when used as mattresses to obtain good compression comfort; thirdly, A warp-knitted spacer fabric with a 0.25 mm spacer filament fineness provides both comfort and pressure resistance and better meets the needs of most people for a spacer fabric for mattresses. [ABSTRACT FROM AUTHOR]

Centrifugal castings are used to manufacture a wide variety of axis-symmetric parts, in which molten metal is introduced into a pre-heated mould rotating at a certain RPM. Major defects in centrifugal castings occur during the solidification process. The rate of defect can be reduced by controlling the temperature distribution and rate of solidification. However, estimating those values through an empirical approach is very difficult as moving particles disturb temperature equilibrium. This paper focuses on the mathematical modelling of the centrifugal casting process to study the effect of pouring temperature and mould pre-heat temperature on the rate of solidification. The Finite Element Method was used to analyse the temperature distribution. The results obtained represent temperature distribution in both the mould and the molten metal regions. The molten metal is introduced into a pre-heated mould at a temperature of 1500°C and the mould was pre-heated at 250°C to minimize thermal shock. It is observed that there was a drop in temperature from 1419.9°C at a distance of 4.5cm to 1074.9°C at a distance of 6.5cm in cast region and 574.4°C at a distance of 6.5cm to 351°C at a distance of 15.5cm in mould region from the centre of the mould after about 30 secs from pouring the molten metal into the mould. When compared with results from FEA, maximum percentage error was 4.79% and the minimum percentage error of 0.62% have been observed. This comparison was done for temperature distribution in cast and mould regions after about 30 secs from the time molten metal was introduced into the mould. This shows that the results obtained from this research agree with the results from the finite difference method. It is observed that an increase/decrease either in pouring temperature or mould pre-heat temperature directly affects the solidification time significantly. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Española de Cirugía Ortopédica y Traumatologia (English Edition) is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Wood Industry / Drvna Industrija is the property of Drvna Industrija and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study conducts numerical and experimental analyses to study the parameters affecting deep drawing of symmetric low-depth products, such as die geometry, punch movement, and cushioning. The methodology proposed in this paper is applied on the deep drawing of a frying pan manufactured out of AL99.9%. The finite element model (FE-model) is developed using LS-Dyna© and an experiment is carried out to validate the FE-model. The numerical and experimental results have shown minor deviation of 3.5% and 0.92% for maximum pressing load and maximum thickness, respectively. The validated FE-model is then employed to study the parameters affecting the maximum pressing load and maximum thinning. It is proved that the cushion stiffness and the initial blank thickness have the major influence, while the punch speed shows an insignificant impact. The results are justified and hence the FE-model proves to be reliable for further analyses. [ABSTRACT FROM AUTHOR]

Since the last century, concrete has been used to protect structures against intentional or accidental detonation of explosives. Recently, as concerns about terrorist activities and accidents in plants using explosives increase worldwide, the study of the behaviour of this type of material and any civil or military structure under the influence of explosions has increased. Among the lethal effects of explosive devices, which cause greater loads in structural elements is the airblast effect. For this reason, this paper presents a series of airblast finite element (FEM) simulations developed in Abaqus/Explicit®. To validate the computational method, such simulations are geometrically and structurally kept similar to full-scale tests conducted in a blast test area of the Science and Technology Aerospace Department (Brazilian Air Force). Both simulations and tests consisted of seven reinforced concrete slabs with compressive strengths of about 40 to 60 MPa, variable steel reinforcement areas, slab dimensions measuring 1x1 m, and subjected to 2.7 kg of non-confined plastic bonded explosive. The results demonstrated that FEM simulations can predict the rupture of the tested slabs and how the effect occurs, showing a valid method to investigating the response of RC slabs when compared to expensive field tests. Differences in displacements were observed between the results of FEM simulations and blast field tests, mainly caused by the sensitivity of the case studied, limits of computational capacity, and intrinsic variations in the materials and sensors used in the field tests. However, these differences showed an order of magnitude compatible with the safety coefficients used with RC, demonstrating that the method can be used for the design of RC slabs under the effect of airblast. [ABSTRACT FROM AUTHOR]

This paper presents results of numerical investigation of the specifics of elastoplastic deformation and damage accumulation in representative volume elements (RVEs) of open-cell and closed-cell porous metal materials under tensile and compressive loads. The Johnson–Cook model was used to describe the elastoplastic behavior and fracture of the aluminum matrix material. Fracture propagation in RVEs of porous media needs to be modeled with explicit consideration for morphological parameters of the internal structure. This feature can be used to form structures with tailored mechanical response using recent advances in additive manufacturing technologies. These technologies, also referred to as 3D printing, provide a free choice of topology by using predetermined digital models that can be optimized before being implemented as real objects. This leads to a task of estimation of the effect of controlled topology on the mechanical behavior of the designed porous structures. The obtained results demonstrate the effect of variation of morphological properties on the elastoplastic behavior and fracture of bicontinuous metal structures under tensile and compressive loads. [ABSTRACT FROM AUTHOR]

Mesh smoothing is an essential technique for the improvement of mesh quality in finite element analysis, due to the fact that mesh quality has a large impact on the convergence of the computational scheme and the accuracy of the numerical results. A novel mesh smoothing method based on regular-position-guided operations is presented in this paper. The method introduced here contains two main stages: The first stage computes the regular position of each vertex based on the shape of the element and conducts regular-position-oriented-based element transformations independently; the second stage determines the finial position of each vertex according to its surrounding elements with an assembly strategy. This method is not limited to planar triangular mesh, but applicable to surface polygonal mesh. Numerical experiments on various mesh models demonstrate the effectiveness and potential of this method. [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]

Structural Health Monitoring (SHM) implementations on infrastructures, including bridges, are currently experiencing a surge in popularity as the favoured solution for preserving structural health. Additionally, the availability of a diverse array of SHM systems is a direct response to the increasing range of structures, the necessity to target specific damage mechanisms, the various monitoring objectives, the utilization of different sensor technologies, and the practical aspects of implementation. Hence, the research domain is challenged with the excessive state of subareas and integrations of techniques used which induced the need to organize the known knowledge about SHM practicalities, focusing on steel superstructure bridges and bridges with steel as main component. In order to gain a comprehensive understanding of this field and provide researchers with a clear perspective on SHM, it is essential to familiarize ourselves with the techniques that have been employed. To that aim, a thorough search was undertaken to locate publications dealing with terms such as "structural health monitoring," "vibration-based SHM," and "steel bridge/bridges". Scopus databases were checked for articles on vibration-based structural health monitoring for steel bridges and PRISMA procedure was conducted to apply systematic review process. The result highlights the profile of the publication trends under the topic throughout the year and the research phenomenon based on country of origin. Then, the result also reviews the studied steel bridge type to explore the propensity of vibration-based practicality based on structural configuration. Then, the heart of this paper, which is the third part reviews the methods that has been investigated by past researcher in the work of bridge vibration characterisation for SHM. The future of vibration-based methods is potentially tremendous as structure characterisation solution as it provides the state-of-the-art data-driven measures towards damage detection. However, the raise of SHM robustness has simultaneously raised the room for advancement towards achieving precise quantification and interpretation from vibration-based techniques. The room for advancements raised in this study has proven our one step forward to provide future studies of ways it can expand the vibration-based frontiers. [ABSTRACT FROM AUTHOR]

In this paper, the sensitivity of a plastic-damage-based structural damage index on mesh density is studied. Multiple finite element meshes with increasing density are used to investigate their effect on the damage index values calculated from nonlinear finite element simulations for a reinforced concrete column subjected to cyclic loading. With the simulation results, this paper suggests a correction method for the objective damage index based on nonlinear regression of volumetric tensile damage ratio data. The modified damage index values are presented in the quasi-static cyclic simulation to show the efficacy of the suggested correction method. [ABSTRACT FROM AUTHOR]

The inside-out ceramic turbine (ICT) is a promising concept to increase turbine inlet temperatures in microturbines by integrating individual monolithic ceramic. This architecture uses a carbon-polymer composite rim to support the blades mainly in compression. High tangential velocities lead to elevated radial displacement of the rim, and therefore, the rotor hub needs to have sufficient compliance to follow this radial displacement. However, the rotordynamics of a flexible hub is not widely understood. This paper presents the rotordynamic analysis of a highly flexible hub for an ICT architecture. Finite element modeling (FEM) is used to design a simplified turbine prototype that maximizes the hub flexibility to explore the limits of the concept. The rotordynamics behavior of the highly flexible hub is measured by spinning a 171-mm diameter prototype up to 49 krpm. This paper highlights three principal challenges of this particular rotordynamics. First, critical speeds mode shape becomes highly coupled with bearings displacement, shaft bending, and hub deformation. At high-speed, the hub deforms out of phase with the shaft, which can cause high stresses in the hub. Second, the angular position between unbalance masses of the flexible hub and the composite rim changes the unbalance response significantly. Finally, vibration causes high stresses in the hub, due to the relative displacement between the composite rim and the shaft, which could lead to failure of the hub. Nevertheless, the rotordynamics of an ICT configuration is manageable as long as the vibration-induced stress in the hub is kept under its limit. [ABSTRACT FROM AUTHOR]

The paper presents the main theoretical backgrounds and application of FE program ATENA to simulation of severe accident in nuclear structures. The software was developed by Cervenka Consulting, Prague, Czech Republic with the aim to offer a tool for numerical simulation of concrete structures subjected to actions in service, ultimate as well as extreme limit states due to mechanical as well as physical effects. Nonlinear behavior of concrete is modeled by theories of damage and plastic flow [1]. Paper outlines the basic features of the used material model. It demonstrates the model accuracy on results from recent blind prediction competitions [2]. In the last section, it shows examples of simulations of severe accidents scenarios in nuclear power plants structures [4]. [ABSTRACT FROM AUTHOR]

Currently, there is a clear need for reliable procedures for condition assessment and service-life evaluation of existing infrastructures. Advanced 3D Nonlinear Finite Element (3D NLFE) analysis has proven to be capable of describing the behavior of reinforced concrete provided that detailed and appropriate condition assessment data are available. The present study aims to review and compare different procedures for coupling 3D NLFE analysis with condition assessment data to model corrosion induced cracking, and consequently to find a method with better accuracy, less computational cost, and improved robustness. This paper introduces a new method for adding cracked elements directly to the finite element model, called ReFEM. The force-displacement response, ultimate crack pattern, and failure mode from this model are compared with four other methods for a pull out test case on specimens under accelerated corrosion process. Using this method, the force displacement response for the corroded specimens was overestimated by about 70%. However, the trend was promising and the failure mode and crack pattern were correct. Moreover, the analysis continued after the peak point in the force-displacement curve which makes it possible to monitor the behavior of the specimen in the softening regime. [ABSTRACT FROM AUTHOR]

The static and dynamic behaviours of a retaining wall backfilled with tire aggregate are investigated in this paper through conventional designs as well as coupled finite element simulations. First, a literature survey is conducted to compile the key geotechnical engineering properties of tire aggregate. The data show that the properties vary with the shred size and possess properties desirable to be considered as a retaining wall backfill. Geotechnical designs and computer simulations show significant reductions in structural demand in terms of maximum shear force and bending moment, and construction cost in terms of excavation behind the wall, material required for constructing a retaining wall, and the volume of backfill material when tire aggregate is used as the backfill. The results of a parametric study indicate that the economic advantage is significant even with the highest and the lowest values of the key properties and the parameters of input motion. [ABSTRACT FROM AUTHOR]

Live working in distribution work is an important way to ensure normal power supply of power equipment. Live installation tool for robot operation was proposed in this paper in order to reduce the safety accidents occurrence. Through different structures and sensor combinations, it can complete the autonomous operation by cooperating with robot, including lead wire monitoring, line detection and tightening the puncture clamp. Finally, the finite element analysis of gear transmission was carried out, and the results showed that the design of the tool can mees the strength requirements. [ABSTRACT FROM AUTHOR]

Shallow Tunneling Method has been widely applied in the construction of pipe gallery. However, due to the complexity of strata and the particularity of environment, improper construction may cause uneven settlement of urban road, even pavement collapse. In the paper, in reliance on Beijing Xi'anmen Street Heat Supply Pipeline Works and by virtue of drilling and survey, the engineering geological conditions and pavement structure of the target area were ascertained, Finite Element Method was utilized for numerical calculation, so as to determine the surface settlement & deformation laws under different construction situations, including the change law of longitudinal and lateral pavement settlement following the progress of excavation, and also the final pavement settlement and settlement scope, etc. It was found by research that, under the joint action of variable section of pipe gallery and shaft pipeline, the section height of pipe gallery has marked effect on the change of pavement settlement, the settlement speed of pavement monitoring point appears to be "double-peak type". [ABSTRACT FROM AUTHOR]