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This project's objective was to create a circular economy in the composites sector by examining the possibility of using wind turbine blade composite materials to construct noise-absorbing barriers for roads. The possibility of constructing road noise barrier panels from components obtained from turbine blades was conceptually examined, and the geometry and construction of wind turbine blades were evaluated for their suitability as filler components for panels. The tensile strength parameters of two types of composites made from windmill blades—a solid composite and a sandwich type—were established based on material tests. The strength of the composite elements cut from a windmill propeller was analyzed, and a three-dimensional numerical model was created using the finite element method. The strength values of the composite used to construct the noise barriers were compared with the stresses resulting from loads operating on the road noise barriers, as determined in compliance with current standards. It was discovered that acoustic screens composed of composite materials derived from wind turbine blades may withstand loads associated with wind pressure and vehicle traffic with sufficient resistance. In order to evaluate the environmental benefits resulting from the use of composite material made from wind turbine blades to make noise barriers, this study presents the values of the embodied energy and embodied carbon for several types of road noise barriers using life cycle assessment. [ABSTRACT FROM AUTHOR]

In the present study, the stability and failure phenomena of thin-walled constructions subjected to axial compression, featuring a central cut-out, and constructed from composite materials were explored. These constructions were fabricated from a carbon–epoxy composite using the autoclave method. The research encompassed experimental assessments on actual specimens alongside numerical analyses employing the finite element approach within the ABAQUS® software. The investigation spanned the entire load spectrum up to the point of structural failure, incorporating both practical trials and simulation analysis. During the practical assessments, the study monitored the post-buckling response and captured acoustic emissions to thoroughly evaluate the composite's failure mechanisms. Additionally, the ARAMIS system's non-invasive three-dimensional scanning was employed to assess deformations. Theoretical simulations utilized a step-by-step failure analysis, initiating with failure onset as per Hashin's theory and proceeding to failure progression based on an energy criterion. The simulation outcomes, particularly concerning the critical and post-critical phases, were juxtaposed with empirical data to identify the composite's vulnerability zones. The comparison underscored a significant concordance between the simulation predictions and the empirical findings. [ABSTRACT FROM AUTHOR]

Remarkable characteristics like simple structure, high starting torque, simple maintenance, good efficiency at all speeds and cost-effectiveness have made switched reluctance machines (SRMs) suitable candidates for electric cars, electric bicycles and variable speed applications (VSAs) such as wind turbines. In this paper, a three-phase Outer-Rotor SRM (ORSRM) with 6 stator poles and 10 rotor poles (6/10) for VSA has been investigated. Unlike conventional SRM structures such as 6/4 and 12/8, an SRM model with higher number of rotor poles can reduce torque ripple much more effective than conventional SRMs. First, the SRM design is done accurately, then, by changing some parameters, the sensitivity analysis is performed on torque ripple and average torque. Finally, the optimisation process on the geometry and structural dimensions of the SRM like rotor pole arc, stator pole arc, rotor yoke thickness, rotor pole height, rotor diameter and the number of turns per phase are executed to minimise the torque ripple and maximise the average torque via genetic algorithm (GA). The initial design, optimisation and performance of the proposed model are validated via a 2-D finite element method (FEM) technique by ANSYS-Maxwell. [ABSTRACT FROM AUTHOR]

This article focuses on the computational analysis of sandwich composite materials based on polypropylene, polyester, glass, and cotton fibers. In the automotive components prepared from these fiber materials, the various components are used in different proportions. Through the manufacturing process, isotropic materials become somewhat anisotropic. Part of this article is aimed at obtaining input values of material characteristics for calculations using finite element analysis (FEM) and the comparison of experimental results with FEM-based material models created using the Digimat 2023.1 software. This article analyzes the modeling of two-phase as well as multiphase composite materials. This work focuses on calculations using FEM according to the test defined in the PR375 standard for loading the finished product in the luggage compartment of a car. The defined methodology enables the application of the FEM-based calculation directly to the product design in the initial phase of research. The construction and production of expensive prototypes and the subsequent production of automotive parts is replaced by computer-based simulation. This procedure makes it possible to simulate several optimization cycles over a relatively shorter time. From the results of computational simulations, it is clear that materials based on PP/PET/glass fibers show a much higher modulus of elasticity than materials created using cotton, i.e., materials of the PP/PET/cotton type. In order to achieve a high strength and stiffness, it is, therefore, appropriate to use glass fibers in the composite materials used for such applications. [ABSTRACT FROM AUTHOR]

Determining the properties of composite materials (knowing the properties of the component phases) is a primary objective in the design phase. Numerous methods have been developed to determine the elastic constants of a composite material. All these methods are laborious and require significant computing time. It is possible to make experimental measurements, but these too are expensive and time-consuming. In order to have a quick estimate of the value of the engineering constants of a new composite material (in our study a polymeric matrix reinforced with carbon fibers), this paper proposes a quick method for determining the homogenized material constants, using the finite element method (FEM). For this, the eigenfrequencies of a beam specimen manufactured by the studied composite material will be computed using FEM. The model will consider both phases of the composite, with the geometry and real size. The mechanical properties of the constituent's material phases are known. With the help of this model, the torsional, longitudinal and transverse vibrations of the beam are studied. Based on the eigenvalues obtained by this calculation, it now is possible to quickly estimate the values of homogenized material constants required in the design. An example for a fiber-reinforced polymer composite material is provided in the paper. [ABSTRACT FROM AUTHOR]

Structural health monitoring (SHM) has attracted significant attention over the past two decades due to its ability to provide real-time insight into the condition of structures. Despite the development of several SHM systems for long-span bridges, which play a crucial role in the assessment of these structures, studies focusing on short- or middle-span bridges remain scarce. This research paper presents an efficient and practical bridge monitoring and warning system established on a middle-span bridge, a key crossroad bridge located in Shenzhen. The monitoring system consists of sensors and measuring points that collect a substantial amount of data, enabling the close monitoring of various operational indicators to facilitate the early detection of threshold exceedances. Based on this system, the subtle condition of the bridge can be evaluated, and the operational condition of the bridge can be studied through the comparative analysis of the collected data. Over four months of monitoring, data including the strain and creep of the main beam, the strain and settlement of piers and the crack width of the bridge body are observed. Furthermore, the real-time operational status of the bridge is analyzed and evaluated through the combination of the collected data and the structural finite element model. [ABSTRACT FROM AUTHOR]

This study used experimental measurements and the finite-element method (FEM) simulations to inves- tigate transient underwater radiated noise induced by the impulse excitation of water surrounding a water- tight steel-structured circular cylindrical shell submerged in the 176 x 8 x 4 m towing tank. The excitation was caused by dropping an iron block onto a structural bracket in the shell to generate structural vibration. The experimental results were found to be consistent with the FEM results, with the difference between the ex- perimental and simulated sound pressure levels being less than 3 dB. Moreover, it was determined that the structural vibration also generated airborne noise in the cylindrical shell, but this contributed much less than the impulse excitation to the induction of underwater radiated noise. Finally, analysis of the sound field of the underwater noise radiation showed that it was influenced by the wall thickness of the watertight steel cylindrical shell and that of the reinforced bracket seat structure. In particular, the structural reinforcement position proved to be the diffusion breakpoint of the underwater sound radiation. This demonstrates that compared with the studied structure, a thicker and more complex reinforced structure will transmit less or incomplete sound radiation into water. [ABSTRACT FROM AUTHOR]

Repairing structures damaged by fatigue through the use of composite patch bonding is an efficient and economical process to preserve structures and increase their lifespan. Much work is currently being carried out to improve this technique. In this work, a 3D nonlinear numerical simulation by finite element analysis was carried out to study the behavior of the crack front and determine the evolution of the stress intensity factor and the change of stresses with respect to distance from the crack point. for an aluminum alloy plate containing a central crack, repaired asymmetrically with a composite patch. The repair of these plates must be more precise and reinforced around the crack point, therefore the stresses are high and the stress integrity factor SIF is more important according to the results of this study. [ABSTRACT FROM AUTHOR]

Due to a number of advantages, such as a high ratio of power transmitted to the weight of the system, the possibility of easy control and the freedom to arrange system elements on the machine, hydrostatic drive is one of the most popular methods of machine drive. The executive elements in such a system are hydraulic cylinders that convert the energy of the pressure of the liquid into the mechanical energy of the reciprocating motion. One of the disadvantages of conventional actuators is their weight, so research is being done to make them as light as possible. The directions of this research include the use of modern engineering materials such as composites and plastics. The paper presents the process of designing, FEM analysis and experimental validation of the base and gland of a composite hydraulic cylinder. The considered elements are made of PET plastic. During the analysis, material nonlinearity was taken into account, and the analysis itself was carried out in two steps. The first was the preloading of the tie-rods, and the second was the loading of the cylinder with internal pressure. The numerical calculations were experimentally validated by prototype tests with the use of strain gauges. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to compare the fracture behavior of interfaces obtained using fourth-generation and universal dental adhesives. The study relies on optic and SEM to evaluate the dentin–adhesive–restoration material interface of the samples and also on FEA simulation of fracture behavior. Specimen fabrication relied on 20 extracted teeth, in which class I cavities were created according to a protocol established based on the rules of minimally invasive therapy. For the direct adhesive technique, the adhesives used were: three-step All Bond, three-batch A and one-step Clearfil Universal Bond Quick-batch B. The restoration was performed with the same composite for both adhesives: Gradia direct posterior. The simulation used a 3D reconstructed molar on which geometric operations were performed to obtain an assembly that replicated a physical specimen. Material properties were applied to each component based on the information found in the literature. A simplified model for crack propagation was constructed, and using the fracture mechanics tool in Ansys 2019, the stress intensity factors that act at the crack tip of the adhesive interface were obtained. Mechanical simulation and microscopic investigation showed us how the interface of the dentine–adhesive–filling material performed in cases of both dental adhesives and for a certain loading condition. Important differences were identified among the adhesives, the fourth generation being superior to the fourth generation especially due to the separate steps in which the tooth surface was prepared for adhesion. [ABSTRACT FROM AUTHOR]

For the first time, a modified two-dimensional Fourier series approach is proposed for new thermal buckling analysis of rectangular thin plates under various edge conditions. The solution form of plate deflection is considered to be in terms of a double Fourier Sine series (Navier-form solution) whose derivatives are determined via utilizing the Stoke's transform technic. The present study exhibits the following significant merits: (a) the method adopted allows one to consider any possible combination of boundary conditions with no necessity to be satisfied in the Fourier series; (b) the given solution procedure is simple and straightforward since the complicated boundary value problem (BVP) of partial differential equation (PDE) can be changed into solving sets of linear algebra equations, which heavily decreases the complicated mathematical manipulations of plate thermal buckling problem; (c) all the results acquired converge rapidly because of using the sum function of series. Greeting agreements between the present analytical solutions with the numerical results provided by FEM testifies the accuracy of the approach proposed. The present results are believed to be severe as new benchmarks for validating other methods and providing better design for plate structures. The influences of the aspect ratio and boundary condition on the thermal buckling behaviors of plates are also investigated and discussed. Furthermore, it is capable to extend the present solution procedure to deal with problems of plates under more complex edge conditions by ways of utilizing other Fourier series. [ABSTRACT FROM AUTHOR]

The influence of mould level instability during continuous casting on the unevenness of the initial solidified shell in hypo-peritectic steels has been investigated. Water model experiments and in-plant casting experiments revealed that mould level instability, which increases with increasing casting speed, is related to longitudinal cracking resulting from the unevenness of the solidification shell. A numerical model which considers the effect of mould level instability was developed and used to simulate the formation of the unevenness of the solidification shell and solidified shell deflections. The calculation results show that an increase in the non-uniform infiltration of mould flux increases the unevenness of the solidified shell. On the other hand, the unevenness of the solidified shell decreases due to mild cooling. Overall, the results of the plant tests and calculations show that non-uniform infiltration of mould flux dramatically affects air gap formation and the unevenness of the solidified shell. [ABSTRACT FROM AUTHOR]

The main aim of this study was to perform a complex biomechanical analysis for a custom-designed temporomandibular joint (TMJ) prosthesis in combination with a fibular free flap in a pediatric case. Numerical simulations in seven variants of loads were carried out on 3D models obtained based on CT images of a 15-year-old patient in whom it was necessary to reconstruct the temporal-mandibular joints with the use of a fibula autograft. The implant model was designed based on the patient's geometry. Experimental tests on a manufactured personalized implant were carried out on the MTS Insight testing machine. Two methods of fixing the implant to the bone were analyzed—using three or five bone screws. The greatest stress was located on the top of the head of the prosthesis. The stress on the prosthesis with the five-screw configuration was lower than in the prosthesis with the three-screw configuration. The peak load analysis shows that the samples with the five-screw configuration have a lower deviation (10.88, 0.97, and 32.80%) than the groups with the three-screw configuration (57.89 and 41.10%). However, in the group with the five-screw configuration, the fixation stiffness was relatively lower (a higher value of peak load by displacement of 171.78 and 86.46 N/mm) than in the group with the three-screw configuration (where the peak load by displacement was 52.93, 60.06, and 78.92 N/mm). Based on the experimental and numerical studies performed, it could be stated that the screw configuration is crucial for biomechanical analysis. The results obtained may be an indication for surgeons, especially during planning personalized reconstruction procedures. [ABSTRACT FROM AUTHOR]

Road transport plays an important role in the transport of goods and people and is important for the national economy. Damage usually excludes the means of transport from operation, which causes disruption of supply chains. One such damage is the failure of the suspension system of the vehicle or trailer, which usually occurs when the vehicle is heavily loaded. Such a defective system has been analyzed in this publication. Mathematical apparatus and finite element method (FEM) numerical simulations were used. A dangerous axle cross-section in terms of load was indicated and the maximum stresses in this area were calculated for two types of roads. On highways, the stress at the critical point was 199 MPa, and on uneven roads it increased to 304 MPa, which is comparable to the yield point. It was found that the second form of vibration may cause stresses in the damage area, but the excitation frequency would have to be quite high. The probability of such a load and failure event occurring is low under operating conditions. [ABSTRACT FROM AUTHOR]

In order to design an optimal reinforcement of steel thin-walled beams with composite materials, it is worth analyzing two important, although often overlooked issues, which are the selection of the appropriate thickness of the adhesive layer and the effective anchoring length of the composite tape. This paper, which is part of a wider laboratory study devoted to the strengthening of thin-walled steel profiles, focuses on the second issue. The paper involves a description of laboratory four-point bending tests during which ten thin-walled steel beams made of a rectangular section with dimensions of 120 × 60 × 3 and a length of 3 m were tested. Two beams were taken as reference beams, and the other eight were reinforced using Sika CarboDur S512 carbon fiber composite tape, assuming four different effective anchorage lengths. The impact of the length of the anchoring of the composite tape on the value of the displacements and strains of the tested beams and on the value of the destructive load that caused tape detachment was analyzed. The following phase was numerical analyses carried out in the Abaqus program, which showed high consistency with the results of laboratory tests. In reference to the conducted tests, it was observed that the increase in the anchoring length of the composite tape has a slight impact on the change in the value of strains and displacements in the tested beams. Nevertheless, the increase in the effective anchorage length has a significant impact on the load value at which the composite tapes are detached from the surface of the steel thin-walled beam. [ABSTRACT FROM AUTHOR]

Recent attention has been drawn to breaking reciprocity due to its astounding applications. Metamaterials can be utilized to break the time-reversal symmetry of a system. This paper investigates the theoretical propagation of waves in a space–time modulating medium and presents a novel Fourier series expansion for avoiding flat wave method barriers. The acquired results are validated by comparing them to those reported in the literature and the simulation results in COMSOL commercial software. Additionally, a theoretical function is created to discuss the effect of various parameters on the position and bandwidth of bandgaps. The plane wave expansion (PWE) approach is incapable of predicting the higher-mode bandgaps. In contrast, the proposed technique accurately detects a bandgap, as demonstrated by FEM results. On the other hand, it is demonstrated that the convergence rate of the presented method is significantly higher than that of the PWE method and decreases the computation time appropriately, indicating that this method is more accurate and reliable than the traditional PWE method, particularly in predicting the higher-mode bandgaps. The findings of this study could be utilized for intelligent periodic structures that use piezoelectricity to regulate wave propagation. [ABSTRACT FROM AUTHOR]

Glass fiber-reinforced polymer (GFRP) utility poles are becoming more widespread in European countries. To ensure the integrity and safety of poles, it is necessary to carefully examine their structural features. The purpose of this paper is to present the numerical model of a column made with the engineering simulation software ANSYS and to compare the experimentally determined values of the stresses that lead to column failure close to the inspection hole with the results obtained using the numerical model. The critical buckling and failure loads for GFRP poles, as well as the associated modes of failure, were correctly predicted by the finite element method used in this study. Failure occurred in the middle of the inspection hole's longer edge at a stress level of 220–250 MPa. A comparison of the stress using the ANSYS simulation software that led to the destruction of the column with those measured experimentally using strain gauges revealed a good agreement between their values. [ABSTRACT FROM AUTHOR]

Microfluidic actuators based on thermally-induced actuation are gaining intense attraction due to their usage in disease diagnosis and drug release-related devices. These devices use a thermally-expandable polymer called Expancel that expands once its temperature exceeds a particular threshold value. Achieving such devices that are cost-effective and consume low input power is crucial for attaining efficacy. Therefore, the need for a low-energy consuming actuator necessitates the improved configurations of microheaters that provide the required heat. We report a novel topology of a copper-based microheater called square-wave meander, exhibiting a 44% higher output temperature, showing high actuation efficiency, as compared to the conventionally used meander design. The reason for increased temperature with low input energy is attributed to increased resistance by a jagged structure while maintaining the same surface area, i.e. without changing the effective thickness of the microheater. Numerical modeling demonstrates the comparison of temperature and electric potential contours for reported and conventionally used microheaters. We reveal the merit of the reported design by comparing the volumetric thermal strains for both designs. We experimentally demonstrate the increased expansion of 25% for the reported design at the same applied current of 200 mA and faster operation time. Later, we show the microfluidic actuator device integrated into the microheater and poly-dimethylsiloxane-Expancel, controlling the operation/actuation of a fluid through a microchannel. This work might improve the performance of the advanced microfluidic-based drug release and other fluid-based applications. [ABSTRACT FROM AUTHOR]

Either due to trauma, extraction or congenital factors, the absence of teeth has aesthetic, functional, financial and psychological consequences. The aim of the current study is to assess an individualized polymeric 3D printed digitally planned surgical guide designed to achieve precision and predictability in non-standard mini-implant orthodontic cases. Twenty-seven patient records with missing anterior teeth were selected from the database of a private clinic in Timisoara, Romania. Based on the analysis of the cases included in the research, a surgical guide for the insertion of mini-implants as provisional crown support was designed. An FEM simulation was performed using the Abaqus numerical analysis software. Finite element simulation revealed the maximum displacements and stresses that occur in the surgical guide. Mini-implant supported provisional crowns can be a simple and low-cost method to increase patient self-esteem and compliance with the orthodontic treatment. Computer aided mechanical simulation is a useful tool in analyzing different polymeric surgical guide designs before being used in clinical situations in order to avoid failure. [ABSTRACT FROM AUTHOR]

Abstract This research explores the finite integral transform approach for analytical thermal buckling solutions of composite thin plates with all edges rotationally-restrained, which is difficult to handle by other analytical approaches. Performing the transformations defined on the governing thermal buckling equation and the boundaries investigated, which yields the transform coefficient for the deflection. Incorporating the inversion formula to satisfy the remaining boundary restraints yields sets of homogenous linear algebraic equations, which determines the critical temperature and corresponding mode shapes for plates. In addition, we provide new exact solutions for non-Levy-type plates via setting the rotational restrained coefficient. The precision and efficiency of the present solutions were well validated by precise FEM analysis. It is promising to develop the present approach for seeking more analytical solutions for intractable moderately-thick/thick plate problems. RESEARCH HIGHLIGHTS Finite integral transform approach for new exact thermal buckling analysis of fully rotationally-restrained composite rectangular thin plates is developed. New analytic exact thermal buckling solutions of plates under non-classical/non-Levy-type boundaries are obtained. Comprehensive benchmark numerical and graphical results are presented. The method is promising to explore new analytic solutions for intractable problems of plates based on different shear deformation theories. Finite integral transform approach for new exact thermal buckling analysis of fully rotationally-restrained composite rectangular thin plates is developed.New analytic exact thermal buckling solutions of plates under non-classical/non-Levy-type boundaries are obtained.Comprehensive benchmark numerical and graphical results are presented.The method is promising to explore new analytic solutions for intractable problems of plates based on different shear deformation theories. [ABSTRACT FROM AUTHOR]

A single stage high-pressure turbine disk has been designed for a low bypass turbofan engine. The turbine disk operates at extreme operating conditions of temperature and rotational speed with cyclic load due to high throttle excursion. The complex mission profile of these engines demands reliable operation of the turbine throughout the flight envelope maintaining structural integrity. Therefore, qualification of the HP turbine disk is a challenging task. This paper presents the analyses and qualification tests carried out on HP turbine disk to examine the structural integrity as well as the life of the turbine disk. Successful completion of the qualification tests assure the airworthiness of the turbine disk for the aero engine for safe and reliable operation within the flight envelope. [ABSTRACT FROM AUTHOR]

Remarkable characteristics like simple structure, high starting torque, simple maintenance, good efficiency at all speeds and cost-effectiveness have made switched reluctance machines (SRMs) suitable candidates for electric cars, electric bicycles and variable speed applications (VSAs) such as wind turbines. In this paper, a three-phase Outer-Rotor SRM (ORSRM) with 6 stator poles and 10 rotor poles (6/10) for VSA has been investigated. Unlike conventional SRM structures such as 6/4 and 12/8, an SRM model with higher number of rotor poles can reduce torque ripple much more effective than conventional SRMs. First, the SRM design is done accurately, then, by changing some parameters, the sensitivity analysis is performed on torque ripple and average torque. Finally, the optimisation process on the geometry and structural dimensions of the SRM like rotor pole arc, stator pole arc, rotor yoke thickness, rotor pole height, rotor diameter and the number of turns per phase are executed to minimise the torque ripple and maximise the average torque via genetic algorithm (GA). The initial design, optimisation and performance of the proposed model are validated via a 2-D finite element method (FEM) technique by ANSYS-Maxwell. [ABSTRACT FROM AUTHOR]

Incremental sheet forming represents a relatively new process appointed to form sheets of pure metals, alloys, polymers, and composites for the manufacture of components in fields where customized production in a short time and at a low cost is required. Its most common variant, named single-point incremental forming, is a flexible process using very simple tooling; the sheet is clamped along the edges and a hemispherical-headed tool follows a required path, to deform the sheet locally. In so doing, better formability is reached without any dedicated dies and for low-forming forces, which represent some of the attractive features of this process. Nevertheless, and with special reference to thermoplastic sheets, incremental formed parts suffer from peculiar defects like twisting and wrinkling. In this numerical work, analyses were conducted through a commercial finite element code by varying the toolpath strategy of the incremental forming of polycarbonate sheets. The investigation of some features like the forming forces, the deformation states, the energy levels, and the forming time was carried out, to determine the toolpath strategy able to optimize the incremental forming process of polymer sheets. The results of the numerical analyses highlight a reduction of the forming forces when using toolpaths alternating diagonal up and vertical down steps and, presumably, a reduced risk of failures and defects. Furthermore, these toolpath strategies solutions also have a positive impact on the environment in terms of energy and do not significantly increase the manufacturing time. [ABSTRACT FROM AUTHOR]

The present paper presents aspects related to the analysis of the cylindrical gears of the central drum gear of the sled-type forestry cableway. This analysis helps to choose and correctly size the gear in the cableway winch drum. Based on the analysis performed on the gears teeth shapes, the analysis of the gear lubrication, and the analysis of the backlash of the teeth the final shape of the gear drive system will be presented. At the end of the work, the analysis with finite elements of the cylindrical gear is presented in order to obtain the optimal structure. [ABSTRACT FROM AUTHOR]

Magnetic hyperthermia (MH) is a new generation cancer treatment method in which magnetic energy is converted into heat energy. One of the challenges with this method is the limited control of magnetic nanoparticle (MNP) oscillations. New approaches such as localizing MNP oscillations are being explored to overcome this problem. In this study, single and dual positioning of static magnetic field (SMF) sources and control of magnetic field-free zone (FFR) form were investigated. Finite element method simulation is used to examine the gradient patterns. Gradient patterns were created and mapped with the distance dependent parametric changes with the experiment setup. According to the findings, it is seen that in some cases the FFR can shrink in the center and in some cases its shape can change from surface-like to line-like. The mapping of the gradient pattern produced by single and dual positioning of permanent magnets for targeted MH use was examined for the first time in this study. [ABSTRACT FROM AUTHOR]

The objective of this work is to present the numerical simulation of the air-bending process of DC01 steel. There are plenty of works concerned with assessing the springback phenomenon in the bending process also using anisotropic material models (Hill's model is widely used). However, very few recent publications are concerned about the fatigue life assessment of bent products. As ensuring the proper fatigue resistance of products is vital for increasing safety and widening the service intervals there is certainly a need to perform investigations in this field. In this work, the air bending simulation of anisotropic DC01 steel with the usage of Barlat's plastic anisotropy model was presented. Together with springback analysis and the equivalent plastic strain cumulation during incremental bending. Strain cumulation is believed to be an important factor in predicting fatigue life. It was shown that the strain development rate depends on the bending process parameters, especially from the bending line orientation to the sheet rolling direction. [ABSTRACT FROM AUTHOR]

In a conventional continuously variable transmission (CVT), the belt slides up and down along the slope of the pulley to shift gears. Efficiency is reduced because of slippage from the shifting of the belt. In this study, the centrifugal belt pulley for CVT were investigated. Instead of applying the belt slip method, a rail groove was machined on the side of the pulley, and a push piece pushed the belt up by centrifugal force along the rail groove. The CVT was designed and manufactured using this mechanism. A CVT tester was manufactured to validate the performance of the proposed transmission. The suitability of the CVT was verified through structural analysis. [ABSTRACT FROM AUTHOR]

Masonry has been used throughout the world and in heritage and historical structures. For this study, two-dimensional (2D) nonlinear finite-element models based on a micromodeling approach were constructed in order to model deformation characteristics of historical stone masonry shear walls subject to combined axial compression and lateral loading. For calibration and validation of the numerical models, previous experimental tests results were considered. To assess critical parameter effects on the behavior of the walls, sensitivity analysis on the calibrated model was conducted. To obtain the overall energy absorption capability of the walls, the loading protocol, and load-displacement hysteresis curves, cyclic analysis of the calibrated model for the dry-stack mortarless sawn stone masonry walls was performed. Numerical analysis results were then compared with experimental test results with general agreement found. [ABSTRACT FROM AUTHOR]

The purpose of this research is to develop effective methods for the thermal calculation of an electromagnetic mill. The article deals with the structural features of the liquid cooling system of such a device, with direct channel cooling of the induction coils. By analysing the recent research in this area, I have revealed that in order to achieve this goal it is expedient to use the finite element method (FEM). I have also suggested the input data for the boundary values to calculate a three-dimensional thermal field of an electromagnetic mill with an internal diameter of the working chamber of 200 mm. I have also graphically shown the results of calculating this problem using FEM analysis. Based on the analysis of the temperature field and gradient, I have also synthesized and substantiated the structure of the thermal equivalent circuit, which approximates the active part of the mill with a complex of five bodies with internal heat release and enables an approximate estimation of its thermal state at the initial stages of design to be held. I have suggested the formulae to calculate the parameters of this equivalent circuit and the principle to form a system of equations for the further determination of unknown temperatures. In addition, I have performed a comparative analysis of the methods for calculating the thermal state. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of the performance of a 22 MnB5 tube after local heat treatment according to a patterning shape under dynamic crash test conditions to propose the patterning shape with the best energy absorption efficiency. Numerical simulations support experimental results to validate the deformation mode during dynamic crash test as well as the strain distribution of the specimen. The helical patterning not only demonstrates the highest axial loading force and energy absorbance in both static and dynamic crash tests, but also can be easily fabricated in a short time. The helical pattern can optimize different pitch sizes according to the thickness and diameter of the cylindrical tube, and it has the highest energy absorption rate with 83.0% in dynamic conditions. [ABSTRACT FROM AUTHOR]

The main objective of this investigation is to reveal the effects of nanoparticle aggregation aligned to thermal radiation with the prescribed heat flux. The Cattaneo–Christov heat flux (non-Fourier) and mass flux (non-Fick's) approaches in the optimized Buongiorno's model have been used to analyze the nanofluid magneto-transport mechanisms over the surface impacted by the gyrotactic behavior of microbe dispersion. The partial differentials are transformed into the set of nonlinear differential equations through boundary layer estimations and similarity substitutions, then computed by applying a variational finite element strategy. Researchers are looking into tiny nanoparticles because they have amazing properties, such as excellent thermal conduction, which are needed in advanced nanotechnology, heat exchangers, materials engineering, and technologies. The significance of this extensive study is to enhance the heat transition. Various aspects of the aggregation parameters on nanofluid velocity and temperature patterns are investigated and visually illustrated concerning the involved physical parameters. The effect of nanoparticle aggregation on the boundary is descending by the including parameters causes an increment in heat transfer rate. A significant correlation has been observed between the sets of results, which represents the accuracy of the finite element method used herein. The computations have been done by reducing the size of the mesh so that the numerical analysis can be used to ascertain convergence in the results. [ABSTRACT FROM AUTHOR]

Chipless tree cutting is increasingly becoming more popular because of its low weight and greater throughput due to the small dimensions of the entire cutting head. This paper is focused on the design of the crank plate of the cutting mechanism of a chipless cutting head. It was necessary to calculate the magnitude of the force required to cut the tree in the direction perpendicular to the growth of the tree fibers. In addition, the tree and cutting mechanism parameters were specified. Due to the size of the cutting force, it was possible to further deduce the amount of the discharge force from the linear motor that directly acts on the opening of the crank plate. After finite element method analysis, it was found that the crank plate was undersized and it was necessary to increase its thickness from 15 mm to 30 mm, which eliminated the problem of plastic deformation. [ABSTRACT FROM AUTHOR]

The effects of the difference of the heat flux between the wide face and narrow face of the mould, the mould taper, casting speed and cooling rate on unevenness of hypo-peritectic steel at the off-corner in the mould, which leads to longitudinal cracking, bleeding and breakout during continuous casting, were evaluated by a finite element model (FEM) simulation and a plant test with a commercial continuous caster. The simulation results show that an increase in the difference in the heat flux between the wide and narrow face increases the off-corner unevenness of solidification because the solidified shell on the low heat flux side is pulled toward the high heat flux side. The analysis results were in good agreement with the plant test results. These results revealed the importance of optimizing the heat flux ratio between the wide face and narrow face mould even under a high casting speed condition. [ABSTRACT FROM AUTHOR]

Although isometric contractions in human muscles have been analyzed several times, there are no FEA models that allow us to use the same modeled joint (the elbow under our case) in different conditions. Most elbow joints use 3D elements for meshing. Representing the muscles in the joint is quite useful when the study is focused on the muscle itself, knowing stress distribution on muscle, and checking damage in muscle in a detailed manner (tendon–muscle insertion, for example). However, this technique is not useful for studying muscle behavior at different positions of the joint. This study, based on the mechanical model of the elbow joint, proposes a methodology for modelling muscles that will be studied in different positions by meshing them with 1D elements. Furthermore, the methodology allows us to calculate biceps and triceps efforts under load for different angles of elbow joint aperture. The simulation results have been mathematically modelled to obtain general formulations for these efforts, depending on the load and the aperture angle. [ABSTRACT FROM AUTHOR]

This article describes a simple cogging torque minimization procedure for interior permanent magnet synchronous machines (IPMSMs), consisting of a progressive modification of the rotor lamination geometry. This procedure can be generalized for the main topologies of PMSM, independently of the number of stator slots or the location of the permanent magnets. For this purpose, a basic IPMSM structure is analyzed by means of the FEM (finite element method) approach, and then, several other IPMSM geometries, obtained by adequately modifying the rotor lamination geometry of the basic IPMSM model without changing its stator configuration, are proposed and discussed. The trends of the cogging torque generated by each model are computed and compared. From this comparison, it is demonstrated that, by simply acting on the shape of the rotor lamination and by choosing the optimized pattern, the cogging torque components can be theoretically canceled. [ABSTRACT FROM AUTHOR]

A thermoplastic matrix composite flat panel stiffened by induction welded stringers, according to a typical aerospace configuration was tested. A Poly‐Ether‐Ether‐Ketone (PEEK) matrix reinforced by carbon fibers was adopted. The aim of this study was to investigate the shear buckling, a load condition that is very common for the aerospace structures, of the panel obtained using a non‐conventional approach for its fabrication, that is, induction welding. A finite element (FE) model capable to describe the buckling and the postbuckling behavior of the stiffened panel was also developed and compared with experimental results. Testing was performed using fixtures suitably designed to transmit a pure shear to the panel, and strain gauges were mounted on the external surfaces to measure the deformations. [ABSTRACT FROM AUTHOR]

As part of the activities performed by the DEMO Central Team (DCT) to study alternative configurations of the Water-Cooled Lead Lithium (WCLL) Breeding Blanket (BB), to overcome the open issues that emerged at the end of the Pre-Conceptual Design phase, a new concept, the WCLL BB "double bundle" (db), was developed. This concept adopts an array of db tubes poloidally distributed inside the breeding zone, mimicking the arrangement inside heat exchangers. These are coaxial pipes the gap between which is filled with PbBi (or alternatively with gas and fins), which avoids direct contact between PbLi and water in case of in-box LOCA events. Similarly, the First Wall channel cooling water is separated from the PbLi. The use of PbBi as an inert fluid makes the Segment Box (SB) sizing less stringent: in the case of an in-box LOCA due to a break of the water cooling circuit inside the BB SB, the pressurized volume is only the PbBi one, instead of the whole SB volume as in the reference WCLL design configuration. Consequently, the total amount of steel inside the BB can be reduced, with benefits in terms of increased tritium breeding ratio. Within this framework, University of Palermo, in support of the DCT and under the EUROfusion action, preliminarily analysed the steady-state thermal, thermo-hydraulic and normal and off-normal thermo-mechanical performances of this concept, following a theoretical-numerical approach based on finite volume and finite element methods, and adopting the ANSYS CFX and ANSYS Mechanical codes. The analyses carried out allowed a preliminary optimization of the design, improving the thermal and thermo-mechanical performances of the WCLL-db BB, in compliance with the design requirements, while reducing the total steel amount. Models, assumptions and main results are herewith reported and critically discussed. [ABSTRACT FROM AUTHOR]

This paper presents a detailed analysis of current unbalance in a conventional switched reluctance motor (SRM) even under healthy operating condition at steady state. It is pinpointed that the phenomenon is quite expected and originates from inherent unbalance in the flux path variables. The phase currents of the motor are found asymmetric with different peak values during the normal operation, which is apparently paradoxical. Interestingly, it is also noted that the difference between the peak phase current values is varying with the load. FEM based analysis has been performed with two different terminal connection of the phase windings to the power electronic converter. The simulation results have established the effect of terminal connections of the phase winding to the power electronic converter in motor current profile. These effects are duly explained using magnetic circuit concepts and thereafter justified through detailed analytical derivations. mmf drop calculations convincingly established that the phase current unbalance arises from inherent flux path asymmetries during phase switching. The results from mathematical analysis and simulations are corroborated by accurate experimental results. [ABSTRACT FROM AUTHOR]

Steel joints made out of circular hollow section profiles are used for many fields of applications, such as wide-span or representative halls for airports. By connecting two inclined pipes to a vertical third pipe, a ramified vertical column is created, where the node is the weakest point in the structure due to the geometrical heterogeneity. The current standards and Design Codes have limitations regarding the geometrical properties of hollow sections joints. However, the kind of steel joint presented in this paper is excluded in the current standards. This paper is about numerical FEA case studies of two-dimensional, circular hollow-section joints to figure out the resistance of atypical steel joints. In the first step, a small-scale model is generated to analyze the influence of the inclination. In the second step, the geometries of the different pipes are extended. The influence of the inclination angle and the stability of the joint are analyzed. It was discovered that the inclination angle between the three pipes has a large influence on the stresses and deflections at the node. By increasing the inclination angle, the maximum applied force can be increased. The extended members change the behavior and the stress distribution. [ABSTRACT FROM AUTHOR]

The paper presents the tridimensional numeric model of an inner slab‐column connection of reinforced concrete, which was previously tested against the punching shear in the lab of the University of Brasília. The numerical analysis has been carried out by the finite element method, using the software ABAQUS. To evaluate the sensitivity of the main factors that influence the responses of the model, a parametric investigation was conducted as per the finite element mesh, mechanical properties of the concrete and plastic parameters of the assumed model for the concrete, named by concrete damaged plasticity model (CDPM). The results of the resistance capacity, displacements, strains, cracking pattern, and failure mode were compared with those obtained experimentally. From this comparison, it was concluded that the numerical model was able to reproduce the punching shear phenomenon with a high level of precision. [ABSTRACT FROM AUTHOR]

Additive technologies using Fused Deposition Modeling (FDM) technology are currently a promising tool for the production of polymeric multicomposites. This paper presents the results of a static 3-point bending test carried out on 3D printed samples of the PLA-TPU composite. The article also discusses initial vibrodiagnostic research and Finite Element Method (FEM) analysis of the 3D-printed composite bushings. The data obtained from FEM analysis served as input data for motion simulation analysis, where the influence of the stiffness of the suspension on the trajectory has been verified. [ABSTRACT FROM AUTHOR]

The authors have been designing a post-installed anchor that fixes itself into concrete material by expanding the anchor tip in an upward direction, and conducted tensile loading tests to confirm its fundamental dynamic characteristics. The test results on three types of test specimens, with anchor morphology as a parameter, indicate that the final failure modes were all anchor bar fractures, and a stable yield strength was confirmed. Additionally, the yield strength characteristics of the proposed anchor in cases where cracks are present on the concrete surface, wherein the anchors are fixed, were experimentally confirmed. [ABSTRACT FROM AUTHOR]

The necessity to improve the energy saving potential of buildings is now a duty. European and national policies are being implemented to address the important decisions being made on this subject. For these reasons, several studies focus on this relevant topic. This paper review not only focusses on it but studies it in-depth. A commercial 3D simulation software was used to design a building sited in Palermo estimating the thermal losses before and after external envelope insulation. In particular, all the thermal bridges (TBs) were analysed with the finite element method (FEM) and mitigated with rock wool insulation. The paper shows the linear thermal transmittance difference and heat flux loss before and after TB mitigation. The results confirm the importance of installing an external insulation layer in the old building envelope. The linear thermal transmittance of TBs and the associated heat flux loss often decrease by more than 50%. [ABSTRACT FROM AUTHOR]

Summary: One of the most challenging objectives of the European research concerning nuclear fusion technology, promoted by the EUROfusion consortium, is to bring stellarator‐type nuclear fusion devices to maturity. To this purpose, studies on a large HELIcal‐axis advanced stellarator (HELIAS), extrapolated from Wendelstein 7‐X and based on a 5‐fold symmetry (HELIAS 5‐B), are currently ongoing. The HELIAS 5‐B stellarator reactor will be endowed with a breeding blanket (BB) system to allow for the self‐sustainability of the nuclear fusion reaction and make it suitable for electricity generation. In this paper, we present the first ever heterogeneous mechanical design and the preliminary structural assessment of a bean‐shaped ring of a HELIAS 5‐B BB sector. The proposed mechanical design, which is based on the helium‐cooled pebble bed (HCPB) BB concept and developed according to the "sandwich" architecture, foresees an actively cooled segment box connected to a back‐supporting structure equipped with manifolds. The internal region (breeding zone) is reinforced by actively cooled steel plates. The proposed heterogeneous design was checked against nominal loads and an in‐box loss of coolant accidental scenario, which is a typical design driver for BBs. The assessment has been performed according to the RCC‐MRx structural design code. Our results are herewith presented and critically discussed, focusing on the potential follow‐up of the HELIAS 5‐B HCPB BB design. [ABSTRACT FROM AUTHOR]

In residential buildings, the connection between the wall and the slab is the most important area for the design to prevent structural failure and heat loss. The research objective is to evaluate the load capacity of connecting shear keys to an existing slab and panel concrete (PC) wall structure, as well as to develop a design for this connection under direct shear and bending. The experimental program included four test specimens, two of which had one shear key and two shear keys for the others for each loading condition. The test results demonstrate that the structural bearing capacity of bending and shear are significantly improved by changes to the dimensions of the slab, the design of the shear key, and the number of ribs, with the ultimate load increased by 54.45% and 56.85%, respectively. In addition, a finite element (FE) model was used to numerically simulate the behavior of all specimens. The crack and load–displacement curves of the numerical simulations were validated against experimental results using the LS-DYNA program, and good agreement was observed, demonstrating the effectiveness of the numerical model for simulating the behavior of the system components. Several critical input parameters, a constitutive model, and a bar–concrete interface are recommended. The experiments and simulations highlight the effectiveness of various technical solutions for boosting the load capacity of the structure. • The new connection for the slab-external wall was designed to improve structural performance in the building. • The load capacity of thermal bridge solutions with one or two shear keys was investigated. • Numerical models were developed to estimate the load capacity and predict crack failure. • LS-DYNA model input parameters were suggested. [ABSTRACT FROM AUTHOR]

The Water-Cooled Lead Lithium (WCLL) and the Helium-Cooled Pebble Bed (HCPB) Breeding Blanket (BB) concepts are the two candidates currently poised to be chosen as the driver blanket for the EU DEMO reactor. Nevertheless, new variants are emerging with the aim of overtaking the potential showstoppers arisen during the WCLL and HCPB BB pre-conceptual design phase. Then, an intense campaign of exploratory studies has been launched in EU to investigate the potential performances of such alternative concepts. Among them, the Water-Cooled Lead-Ceramic Breeder (WLCB) BB concept is one of the most promising. It has been conceived as a trade-off (i.e. an hybrid concept) between WCLL and HCPB BB concepts, trying to take and integrating the best features of both. Since in the reference WCLL geometric layout the Top Cap (TC) region was identified as particularly critical from thermal and mechanical standpoints, so requiring specific design studies, also in the WLCB conceptual design activities a dedicated campaign of analysis has been necessary to preliminarily size the TC region components. Hence, in this paper, the preliminary thermo-mechanical assessment of the TC region of the WLCB BB alternative concept is presented. First, an initial geometric layout has been set-up on the basis of the main features of the reference WCLL BB TC region. Then, thermal analysis under nominal conditions has been performed and the results have shown that modifications were necessary to ensure the compliance with the thermal requirements of the structural material. Finally, once obtained an acceptable geometric layout, mechanical analyses were carried out in order to verify the fulfilment of the RCC-MRx structural design criteria, also considering an off-normal load case. The results showed that this variant is very promising in terms of structural behaviour, whereas further design iterations are necessary to lower the temperature of the breeder zone. • The Water-Cooled Lead-Ceramic Breeder is an innovative Breeding Blanket concept for DEMO. • The Top Cap region is identified as critical from thermo-mechanical standpoints. • Design by analysis procedure looking at the Eurofer maximum allowable temperature. • Verify the fulfilment of the RCC-MRx structural design criteria. [ABSTRACT FROM AUTHOR]

For advanced space missions, meeting the concurrent requirements of increasing payload size while minimizing spacecraft volume can be achieved through the utilization of deployable structures. In a previous study, we conducted a characterization of a thin/walled boom in terms of its interaction between attitude and elastic dynamics when fully deployed. In this current work, we have developed a numerical model to analyze the critical phase of the deployment process. We compared the model's predictions with theoretical expectations and experimental data, and found a strong agreement between them. Additionally, we investigated the effects of bistability on the deployment process by conducting experiments on both a bistable and a monostable boom. Lastly, we performed deployment tests on a free-floating platform, which emulates a small satellite, to quantitatively measure the attitude perturbations caused by the rapid deployment of the boom. [ABSTRACT FROM AUTHOR]

Considering the extensive use of high voltage insulators, the reliable performance of insulators is challenged by various weather conditions such as pollution. According to recent researches under unidirectional wind, polymeric insulators are mostly exposed to non-uniform fan-shaped pollution. In many contamination patterns, the internal surface is covered with higher contamination than the external surface, and the non-uniform contamination shape on the insulator is similar to a ring-shape. In this paper, two conventional types of non-uniform pollution known as fan-shaped and ring-shaped are modeled for a 20 kV polymeric insulator, and a comparison is made in terms of the electric field between the two configurations using different thicknesses and electrical conductivity of the pollution layer. The electric field, during the arc length of the insulator, is studied under clean conditions, uniform contamination, and two types of non-uniform contamination. In addition, the effect of various thicknesses and conductivity of the pollution layer on the electric field distribution of this polymeric insulator is analyzed. The results show that the electric field distribution in non-uniform ring-shaped pollution is much more effective than the fan-shaped type by changing the thickness of the contamination layer. Moreover, ring-shaped pollution has a more uniform field distribution with fewer thicknesses of contamination layer. [ABSTRACT FROM AUTHOR]

• In the ACL repair technique with internal brace group, shear shielding, and notch effect occur at the button-suture-bone fixation point during experimental testing. • The failure load values in the ACL repaired with internal brace are 519 N (±SD 52), and 937 N (±SD 192) in the intact ACL group. • During the cycle load testing, the ACL repaired with the internal brace group is stable, and the ligament is not significantly damaged further. • Stress and displacement values are higher in the ACL repaired with the internal brace group than in the intact ACL group. The internal brace (IB) technique is a promising treatment option for repairing the proximal rupture of the anterior cruciate ligament (ACL). This paper presents a biomechanical evaluation of the IB technique. Sixteen cadaveric sheep knees underwent monotonic tensile tests, cyclic loading, and passive flexion-extension testing. Data were compared in a series of eight control specimens with an intact ACL and eight repaired specimens where the ACL was cut and repaired using the IB. In parallel with the mechanical testing, finite element analysis (FEA) was performed to investigate the influence of IB loading on the femur-ACL-tibia complex (FATC). The 3D geometry of the FATC was reconstructed from CT scans of the sheep. The IB 3D model was integrated with the 3D FATC for FEA to obtain the femur-repaired ACL with IB - tibia complex (FRA-IB-TC) group. For the intact specimens, the mean (±SD) failure load in the tensile testing was 937 N (±192 N), while for the FRA-IB-TC specimens, it was 519 N (±52 N). The FRA-IB-TC remained biomechanically stable during the cyclic loading testing. The FEA demonstrated an increase in ACL stress to 24.59 MPa and displacement values of 0.391 mm. The IB construct exhibited shear and notch effects at the button-suture-bone fixation site. Testing on this sheep model allowed us a parametric analysis of the impact of the IB repair technique. However, the results will need to be confirmed in a human model. In conclusion, although the IB technique has biomechanical drawbacks, the mechanical properties of the technique are satisfactory. [ABSTRACT FROM AUTHOR]

With the development of society, portal frame has been increasingly used in industrial buildings because of light weight, high degree of industrialization, and high economic efficiency. Some existing portal frames need to be reinforced and improved due to the expansion of production and the functional change. As a safe, reliable, and convenient reinforcement method, the external prestressing reinforcement technology is often used to reinforce the portal frame. In this paper, a new type of assembled anchoring joint was designed to connect the steel strand to the steel beam of a portal frame without damaging the original structure. The static loading test was performed by adjusting length of the strut. And the changes of strain and mid-span deflection were investigated. The Midas Gen FEM simulation was used to investigate stress characteristics of the reinforced portal frame, including strain, bending moment, shear force, etc. The experimental results and simulation results were compared to verify effectiveness of the designed joint. The results indicated the new prestressed anchoring joints had the advantages of simple structure, effectiveness, and force transfer path of the joints was clear. Therefore, the new prestressed anchoring joint can be applied to the external prestressing reinforcement of the portal frame. [ABSTRACT FROM AUTHOR]