Computer-aided Software Engineering Research Articles

Stress distribution in resin-based CAD-CAM implant-supported crowns.

This study aimed to evaluate the influence of new resin-based CAD-CAM implant-supported materials on posterior crown restoration stress and strain concentrations. A previous 3D implant model was edited to receive a cement-retained posterior crown manufactured with different CAD/CAM materials (Estelite P Block, Estelite Block II or Estelite Layered Block). Each solid model was exported to the computer-aided engineering software and submitted to the finite element analysis of stress and strain. Material properties were assigned to each solid with isotropic and homogeneous behavior according to the manufacturer information. A vertical load of 600N was applied in the occlusal region of the crown, via a simulated food bolus, and stress was calculated in Von Misses (σVM) for the implant, abutment and screw, Maximum (σMAX) Principal Stresses for the crown and microstrain for the bone. All simulated materials showed acceptable stresses levels with a similar stress pattern among the models. At the crown intaglio region and cement layer, however, differences were observed: Estelite P Block showed a lower tensile and shear stresses magnitude when compared to other resin-based materials with lower elastic modulus. The stress effect of different resin-based CAD-CAM implant-supported crowns is predominant in the crown and cement layer, with Estelite P Block showing 7.4% versus 9.3% and 9.2% for Estelite Block II and Estelite Layered Block of crown failure risk.

Проблемы электродинамических усилий в индукционных нагревателях

Problems are considered related to electrodynamic forces in the powerful induction heaters of industrial and medium frequency. The methods are given for calculating the forces acting on the heated blanks, inductive coils, and magnetic cores. One of the methods is based on the calculation of the total ponderomotive force acting on the current-carrying conductors and ferromagnetic bodies. To implement these methods, general-purpose computer-aided engineering software based on the finite element method and suitable for building electrothermal models is required. Building of such models is a rather laborious process, and the calculations take a significant amount of time, which does not allow the required number of calculations to be carried out within a reasonable time. Other methods are based on the calculation of the partial derivative of reactive power by the required coordinate. Thus, the corresponding projection of the force on the given axis is calculated. In combination with the subject-oriented 2DELTA coupled electrothermal software, this approach allows to perform the required number of calculations with a suitable for practice of induction heating design accuracy and with significantly less time. Comparative analysis was carried out related to the safety of some types of industrial induction installations used for heating various metals. The technological processes of induction heating of copper, aluminum and some steel grades are considered. The main parameters influencing the negative impact of electrodynamic forces are shown. In particular, when analyzing the axial component of such a force, it was established that the force of friction of the heated ingots against the guides has a significant negative effect. In the case of heating of ferromagnetic ingots, the direction and magnitude of the electrodynamic force are also influenced by the thermal regime. The methods are proposed for solving the problems of ensuring electromechanical safety in the design and tests of induction installations.

Improve Product Design and Injection Molding for Electrical Outlet Cover Plastic with the Help of CAE Software

CAE (Computer-Aided Engineering) analysis is based on the sequence characteristics of the system, combining model reasoning to conduct analysis, the results have physical significance, is Know-Why but not the Know-How of traditional experience, thus it is possible to systematize and scientificize the injection molding parameter and design types for the order of state and product quality, achieving the goal of scientific injection molding (Scientific Molding). Due to the reliability of CAE results, it is possible to point out potential problems during injection molding and design, propose design modifications and possible solutions to obstacles and possible solutions, can avoid unsafed experience. CAE at the design stage can be performed on a computer for design modification options to conduct evaluation (Evaluate), evaluate (Verify) and optimize (Optimize), reducing time and cost mold testing, actual mold fixing, shortening actual trial and error cycle, shortening product development time and time-to-market, reducing waste, time and cost in stages. CAE can help injection molders predict and capture injection molding parameters for product quality impact, find out the processing direction (Processing Window) and optimize injection molding parameters. CAE can indicate the main factors affecting the quality of injection molding, thereby providing design modification parameters, injection molding parameters and quantitative criteria. In this article applied the CAE method to improve injection molding added the the best product. There are a lot of results: First of all, when making the mold, we will make the inserts to escape the air at the position of the cylinders. And the air outlet at the edge of the product so that the air at the edge can escape well; After improving the gate position, cooling water line, pressure protection, mold temperature, we see that the product has a change in warping, but it is not significant.

Improve Product Design and Injection Molding for Controler Plate Plastic with the Help of CAE Software

CAE (Computer-Aided Engineering) analysis is based on the sequence characteristics of the system, combining model reasoning to conduct analysis, the results have physical significance, is Know-Why but not the Know-How of traditional experience, thus it is possible to systematize and scientificize the injection molding parameter and design types for the order of state and product quality, achieving the goal of scientific injection molding (Scientific Molding). Due to the reliability of CAE results, it is possible to point out potential problems during injection molding and design, propose design modifications and possible solutions to obstacles and possible solutions, can avoid unsafed experience. CAE at the design stage can be performed on a computer for design modification options to conduct evaluation (Evaluate), evaluate (Verify) and optimize (Optimize), reducing time and cost mold testing, actual mold fixing, shortening actual trial and error cycle, shortening product development time and time-to-market, reducing waste, time and cost in stages. CAE can help injection molders predict and capture injection molding parameters for product quality impact, find out the processing direction (Processing Window) and optimize injection molding parameters. CAE can indicate the main factors affecting the quality of injection molding, thereby providing design modification parameters, injection molding parameters and quantitative criteria. In this article applied the CAE method to improve injection molding added the the best product. There are a lot of results: First of all, when making the mold, we will make the inserts to escape the air at the position of the cylinders. And the air outlet at the edge of the product so that the air at the edge can escape well; After improving the gate position, cooling water line, pressure protection, mold temperature, we see that the product has a change in warping, but it is not significant.

The ability of mouthguards to protect veneered teeth: A 3D finite element analysis.

Professional and amateur athletes might have veneer restorations. The aim of this study was to investigate the protective effect of mouthguards on veneered anterior restorations. A nonlinear dynamic analysis was performed to simulate conditions during an impact with or without a custom-made mouthguard. Using a computer-aided design (CAD) software, a slice of a human maxilla was designed containing an upper right central incisor. The model was composed of mucosa, cortical bone, trabecular bone, periodontal ligament, dentin, enamel, and pulp tissue. The enamel was prepared (feather design), restored with an indirect veneer (1.0 mm thickness), and duplicated to simulate both conditions with or without a mouthguard (4 mm thickness). Both models were subdivided into finite elements using the computer-aided engineering (CAE) software. Frictionless contacts were used, and an impact was simulated in which a rigid sphere hit the model at 1m s-1 . Fixation was defined at the base of the bone. The elastic modulus of the veneer was assessed by using five different restorative materials (resin composite, hybrid ceramic, zirconia-reinforced lithium silicate, lithium disilicate, and zirconia). Von Mises stress, minimal principal stress, and maximum principal stress (in MPa) were obtained and plotted for visual comparison. Von-Mises results showed higher stress concentrations in the veneer's cervical labial region for models without a mouthguard. Observing the quantitative results for each model, the highest compressive (709 MPa) and tensile (58 MPa) stresses occurred in the situation without a mouthguard with a zirconia veneer, while the lowest occurred in resin composite veneer with a mouthguard (8 and 5MPa). The mouthguard was able to reduce the stresses in the tooth structure and it also reduced the risk of fracture in all conditions. Mouthguards were beneficial in reducing the effects of dental trauma regardless of the restorative material used to manufacture the indirect veneer, since they act by dampening the generated stresses during the trauma event. Equal impact stresses on a mouthguard will lead to higher stresses in veneered teeth with more rigid restorative materials leading to a less protective effect.

Consistent Design of Relational Databases using EERCASE

This article introduces EERCASE, a Computer Aided Software Engineering tool that is based on the best practices of the Model Driven Development paradigm to provide a consistent environment for relational database design. EERCASE follows the graphical notation of the Enhanced Entity–Relationship model according to Elmasri and Navathe, implements the EERMM metamodel to avoid syntactically invalid constructs, shows and describes static semantic errors, and generates data definition code that takes into account advanced structural validations. The theoretical and technical framework used for the implementation of EERCASE is discussed, with emphasis on the restrictive and informative validations performed by it. In addition, considering feedbacks on modeling errors and code generation, EERCASE is also presented as a computational environment that favors active learning.

Multiobjective optimization framework for designing a vehicle suspension system. A comparison of optimization algorithms

Recent advances in robotics and digital technologies in the automotive industry, allow the integration of vehicle systems with their virtual twins, thus facilitating their modelling and optimization. As a result, the systems design time and manufacturing costs are substantially reduced, while their performance, safety and fatigue life are expanded.This work presents a multiobjective optimization framework for developing an optimal design of a front double wishbone vehicle suspension system based on a four-bar mechanism. This is carried out by coupling several computer-aided design tools (CAD) and computer-aided engineering (CAE) software. The 3D CAD model of the lower control arm of the suspension system is made using SolidWorks®, the Finite Element Analysis (FEA) of the suspension assembly is modelled using ANSYS® Workbench, while the multibody kinetic and dynamic of the designed suspension system is analysed using MSC ADAMS®. They are embedded in a multidisciplinary optimization design framework (modeFrontier®) with the aim of determining the optimal hardpoint locations of a lower control arm by minimizing the chassis pitch accelerations to improve the passengers’ comfort, reducing the volume and mass of the suspension system to increase the vehicle stability and manoeuvrability, while decreasing the maximum stresses to extend the system fatigue life and enhancing safety.The methodology has been successfully applied to several driving scenarios entailing different vehicle dynamics manoeuvres with the aim to find the Pareto optimal front, and to analyse the suspension assembly performance together with the vehicle dynamic behaviour. Results show that the use of such approach may significantly improve the design of the suspension system. Furthermore, a comparison of different optimization strategies and algorithms is performed.

Influence of CAD/CAM Abutment Heights on the Biomechanical Behavior of Zirconia Single Crowns

The biomechanical behavior of the universal link (titanium base) prosthetic abutment with different heights in implant-supported restorations was evaluated. Forty regular implants (4 × 10 mm) in titanium were used, divided into two groups according to the abutment height (n = 20): 4.5 × 4 mm (short) and 4.5 × 5.5 mm (long). Using CAD/CAM technology, zirconia crowns were milled and cemented onto the prosthetic abutments. Half of the specimens were submitted to the initial maximum fracture load test in a universal testing machine. The long abutments presented fracture load (41.1 ± 6.96 kgf) statistically similar to the short abutments (49.5 ± 7.68 kgf). The other half of the specimens were submitted to mechanical cycling (2,000,000 cycles, 2 Hz with a stainless-steel antagonist with a diameter of 1.6 mm), following ISO 14801:2007. Subsequently, the survival of the specimens was evaluated using the survival analysis function, Kaplan–Meier and Mentel–Cox (log- rank) (p < 0.05). The finite element analysis was performed in similar conditions to those used for the in vitro test through computer-aided engineering software (version 19.2, ANSYS Inc., Houston, TX, USA). The biomechanical behavior of both models was similar regardless of the evaluated structure of the set. It was concluded that both short and long abutment presents promising fatigue behavior and stress distribution for use in long-term implant-supported restorations.

Three-Dimensional Analysis of Vomer Volume and Deviation in Patients With Unilateral Cleft Lip and Alveolus.

Since almost all patients with an alveolar cleft have a deviated and thickened vomer bone, the purpose of this study was to investigate the relationship between the vomer shape and the size of the alveolar cleft in patients with unilateral cleft lip and alveolus (CLA). A total of 40 adult patients with unilateral CLA were enrolled, and 40 normal adults without CLA were enrolled as controls. All patients underwent preoperative computed tomography scans and analysis by computer-aided engineering software to obtain the vomer volume (VV), deviated septal angle (DSA), and alveolar cleft volume (ACV). An independent-sample t test or nonparametric test was used to compare the VV and DSA between the unilateral CLA and control groups. The correlation between ACV, VV, and DSA in the unilateral CLA group was assessed using Pearson correlation analysis or Spearman correlation analysis. Vomer volume was significantly higher in patients with CLA (1595.35±48.45mm3) than in the control group (1043.2±164.976mm3) (P<0.001), as was DSA (13.099±7.0 versus 3.4398±1.74 degrees) (P<0.001). In the CLA group, VV and DSA were significantly associated with ACV (VV and ACV: r=0.886, P<0.001; DSA and ACV: r=0.543, P<0.001), and VV was significantly correlated with DSA (VV and DSA: r=0.582, P<0.001). In conclusion, the vomer is thicker and more convex in patients with unilateral CLA than in people without, and the vomer angle and degree of volume deviation correlate with alveolar cleft severity.

Multi-objective Bayesian hull form optimisation for high-speed craft

Simulation-based design plays an important role in many engineering fields enabled by advancements in computing resources, numerical algorithms and computer aided engineering software. In naval architecture, it opens new opportunities for improving hull form designs by reducing calm water resistance and hence minimising required propulsive energy. In this paper, we propose a low dimensional shape morphing tool suitable for designing novel and realistic hull forms for high-speed craft. We provide an efficient simulation-based design framework for optimising hull forms across multiple operating conditions by taking advantage of a multi-objective Bayesian optimisation method. We demonstrate the proposed framework for optimising the hull form of a conceptual high-speed catamaran at two speeds, corresponding to Froude numbers of Fr=0.35 and Fr=0.65. The results highlight the benefit of multi-objective optimisation for high-speed craft along with a nonlinear CFD (computational fluid dynamics) solver to evaluate design solutions. We show the proposed framework can design highly efficient hull forms along the multi-objective Pareto front that have a reduced total resistance when compared to a generic baseline hull by 31%–43% and 5.7%–8.2% at low and high Froude numbers, respectively.

Simulation and Experimental Verification of Dynamic Characteristics on Gas Foil Thrust Bearings Based on Multi-Physics Three-Dimensional Computer Aided Engineering Methods

This paper presents a method to simulate the dynamic operating characteristics of a gas foil thrust bearing based on linear elastic support and constant ambient temperature to mimic the transient structure–fluid interactions. In the physical model, the top and bump foils are simply represented by an infinite number of Hookean springs attached to a solid wall with a small amount of deformation, whereas the gas film in the bearing is under quasi-steady lubrication flow conditions with hydrodynamic pressure distributed on the little-deformed top foil. A three-dimensional multi-physics model in a cylindrical coordinate system is established via a commercial computer-aided engineering software package to predict the nominal dynamic characteristics of the gas foil thrust bearing. To verify the multi-physics model, an experimental bench was built in-house to measure the thrust force on the support of the bearing. With the pertinent bearing parameters being entered into the package, the simulations agree well with the experimental thrust forces. As a further step, a simulation model of a clamped-rotor gas foil thrust bearing design was thoroughly investigated under nominal operating conditions, resulting in predictions of underdamped oscillations in rotor motions. The phenomenon could be described using a linear mass–spring–damper model that is dependent on the gas film thickness. The stiffness and damping coefficients could serve as a base reference for rotor dynamics analysis. This concludes the potential development of a digital twin for gas foil thrust bearing systems.

La abstracción de agregación en la modelación conceptual de bases de datos. Consideraciones sobre su uso en la docencia

Conceptual data models have been developed to capture the meaning of data using abstraction mechanisms such as association, generalization/specialization, categorization, and aggregation. The use of the aggregation construct in the various Entity-Relationship model notations has been limited because many of the existing notations do not support it. The same is currently the case with CASE tools (Computer Aided Software Engineering) for database design. The objective of this article is to highlight the semantic potential of aggregation and show how its use contributes to the semantic richness of conceptual schemes. This result can be applied in the teaching of conceptual modeling issues in subjects related to databases.

A Common First-Year Undergraduate Engineering Course in Manufacturing based on Industrial Robots and Flipped Classroom

The pedagogy of a first-year engineering course in manufacturing is presented. This course entitled Manufacturing and Society involves collaboration with social science, is based on industrial robots as the central theme to attract students’ interests and utilizes the flipped classroom approach for delivery. We hypothesize that, in one semester, recent high school graduates will be able to gain knowledge in manufacturing by learning the computer-aided engineering (CAD) software, applying CAD to design a penholder, fabricating the penholder using additive manufacturing and computer-aided manufacturing (CAM) software, programming the robot to create a toolpath for the pen, drawing using the pen on the penholder guided by a robot, and elaborating on impacts of robotic painting on society from a social science perspective. This course is designed to give students, regardless of their intended major in engineering, broad knowledge in manufacturing via 10 engineering, 3 social science, and 10 technical communication lectures; 8 labs; and 4 projects. The social science lectures and discussions focus on how knowledge about society can be used to inform design and manufacturing decisions, social science research methods for understanding how engineers and technology can impact people’s lives, and changing trends in work, the workplace, and the future workforce as it relates to manufacturing. This course aimed to give undergraduate first-year engineering students a positive view of advanced manufacturing and its impact on society. Student evaluations and comments were positive and affirmed the learning objective of teaching manufacturing to the first-year engineering students. The flipped classroom approach was demonstrated to be ideal during the COVID-19 pandemic with limited capacity for in-person lectures and labs. The use of flipped classrooms allowed students to learn at their own pace, review and reinforce knowledge, have a closer interaction with instructors, and reduce the number of technical errors using simulation tools. This course with the support of flipped classroom pedagogy can be successfully implemented in the post-pandemic era, devoting the time of the class to answer questions, expand upon the class content and have a closer in-person interaction with students.

An analytical sensitivity theory-based optimization method for composite structures with large-scale variables

This research focusses on large-scale variable optimization techniques for commercial composite wing structures. To achieve a more complete set of results, the layer thickness for composite layers with the same material and ply direction, are set as a design variable in this study. An analytical approach was utilized to deal with the sensitivity analysis so as to study the relationship between displacement, stress and strain constraints. In order to improve the applicability and user-friendliness, the procedure of sensitivity analysis has been programmed within Fortran and integrated into a Computer-Aided Engineering (CAE) software named HAJIF. To compare the consistency and efficiency, the analytical sensitivity calculation method, along with the finite difference method and a semi-analytical method, were employed to optimise a composite aircraft wing structure. The analytical method was found to have the best consistency and efficiency amongst the three optimization methods. With the aid of HAJIF, the wing was optimized with a weight loss ratio of 8.9%. The total optimization time was is 56 times quicker than the finite difference method and semi-analytical method.

Constructing a Software Tool to Optimize Performance by Coupling Detection

Coupling relations reflect the interdependencies of software modules and can be used to assess a program's quality— Lower the coupling value will be, the higher the quality of the software will be. Coupling measures are crucial for determining the quality of object-oriented software, from design up to maintenance. Inside software engineering, quality attributes are realized non-functional requirements utilized to assess whether the software is of good quality or not, One of the quality attributes is Performance, which means the system can respond to various actions in a given time or how fast does it respond or execute. To calculate the total amount of time a program will require to run until completion use Time Complexity. In this paper a Computer Aided Software Engineering Tool has been constructed which is called CDPI (Coupling Detection to Performance Improvement). It parse a software source code to extract information about its structure, components, and relationships that connect its parts. That leads to improving the software readability, understandability and for detects coupling among classes of Java software.The CDPI tool detects coupling in software source code and Show it in table to the software engineer, To start the process of decoupling by the software engineer for the candidate coupling. The CDPI tool was tested by inputting software written in OOP by Java language. The CDPI Tool were evaluated by calculating the Time Complexity before and after decoupling. Results, source code after the decoupling is executed faster than before decoupling to produce the required output, which is an indication of Optimize Runtime Performance of the program.

AIRFLOW SIMULATION AT THE UKRAINIAN ANTARCTIC STATION

The location of the Ukrainian Antarctic Akademik Vernadsky station leads to several problems related to the need to ensure the livelihood and safety of people. The infrastructure of Vernadsky station is affected by significant climatic loads during the year, such as wind, rain, snow and low temperatures. The destruction or even significant damage to the infrastructure of the Antarctic station can endanger the lives of people who are on it due to the inability to evacuate. The purpose of the study is to determine the fields of wind load distribution within the Antarctic Vernadsky station. This is necessary in order to identify the infrastructure objects that are most affected by wind loads. SolidWorks computer-aided design software environment allows you to build geometric models of objects of varying complexity. That is why this system was chosen to model the infrastructure of the Ukrainian Antarctic Vernadsky station. Simulation modeling of wind load was performed in the computer-aided engineering software of finite element analysis ANSYS. Geometric models of the infrastructure objects of the Ukrainian Antarctic Vernadsky station were created. Simulation modeling of the station under wind load conditions was performed. It is shown that in the case of wind from the mainland, the elements of the station's infrastructure that receive the main wind load are the main building and the VST-200. It is determined that the presence of a pile foundation affects the velocity vector fields, so this element should not be neglected when performing further research. It is shown that practically all objects of the station's infrastructure lead to significant turbulent vortices. Geometric models of the infrastructure objects of the Ukrainian Antarctic station Academician Vernadsky were created. Simulation modeling of the station under wind load conditions was performed. It is shown that in the case of wind from the mainland, the elements of the station's infrastructure that receive the main wind load are the main building and the RVS-200. It is determined that the presence of a pile foundation affects the velocity vector fields, so this element should not be neglected when performing further research. It is shown that almost all infrastructure objects of the station lead to significant turbulent tails when they flow around.

Stress Distribution Pattern in Zygomatic Implants Supporting Different Superstructure Materials.

The aim of this study was to assess and compare the stress–strain pattern of zygomatic dental implants supporting different superstructures using 3D finite element analysis (FEA). A model of a tridimensional edentulous maxilla with four dental implants was designed using the computer-aided design (CAD) software. Two standard and two zygomatic implants were positioned to support the U-shaped bar superstructure. In the computer-aided engineering (CAE) software, different materials have been simulated for the superstructure: cobalt–chrome (CoCr) alloy, titanium alloy (Ti), zirconia (Zr), carbon-fiber polymers (CF) and polyetheretherketone (PEEK). An axial load of 500 N was applied in the posterior regions near the zygomatic implants. Considering the mechanical response of the bone tissue, all superstructure materials resulted in homogeneous strain and thus could reconstruct the edentulous maxilla. However, with the aim to reduce the stress in the zygomatic implants and prosthetic screws, stiffer materials, such Zr, CoCr and Ti, appeared to be a preferable option.

Experimental, analytical, and numerical investigations on the flexural and fatigue behavior of steel thin-walled X-section beam

Thin-walled hollow shapes are of great interest in many industries with weight constraints, due to their availability, low price, and strength-to-weight ratio. This paper presents the development, calculation, and production of a thin-walled X-section beam design with a unique section geometry. This hollow X-section beam geometry is a beam that has been developed to use shape-connected jaws on the beam and to use less bolts and mounting elements, and to easily change the positions of the parts mounted on the beam. The bending strength of this unique beam section was investigated, and the fatigue damage of the beam was also handled with technological methods. Using both experimental stress measurements and finite element solution, the static and fatigue strength of the beam were calculated with computer-aided engineering software. The FEM solution was performed nonlinearly by defining the linear elastic and plasticity properties of the material. Validation studies were carried out in the laboratory using three-point and four-point bending tests. These traditional experiments were supported by strain gauge technology that measures strain with 0.05% accuracy. The weight and bending strength of the X-section beam were compared with the hollow section square beam. X-section beam (S355J0H) has 13% lower bending strength than 120 × 120 × 8 mm (S355J0H) beam; however, it is 37% lighter. ANSYS-analytical test results of difference are 3.95%, and ANSYS-experimental test results of difference are 0.85%. Experiments showed that a ∼22% increase in strength is found in these corners depending on the production method. The fatigue behavior of the X-section beam was determined with the nCode DesignLife software using validated FEM solutions and fatigue curves of the materials. X-section beam developed for shape–connected assembly systems can be used especially in the formation of chassis with its superior assembly ability and bending strength, increasing functionality, and production speed.

Stress Concentration of Hybrid Occlusal Splint-Mouthguard during a Simulated Maxillofacial Traumatic Impact: 3D-FEA.

Mouthguards (MG) are protective devices that can reduce the risks of facial trauma. However, many athletes do not use them. Additionally, MG wear with coincidental parafunctional activity has not been considered. The aim of this study was to evaluate the stress distribution as a consequence of a direct impact comparing a conventional MG with a novel hybrid appliance (HMG). Using computer-aided design (CAD) software, a human skull was modeled with the teeth inserted into their respective alveolus. The models were divided according to the MG type (conventional or hybrid). The geometries were exported to the computer-aided engineering (CAE) software and the materials were considered isotropic. Fixation was defined at the base of the maxilla. The load was applied using a hockey puck. The total deformation (mm) and the von Mises stress (MPa) results were obtained for the MGs (conventional and hybrid), upper teeth, lower teeth, and maxillary bone. Despite the presence of an MG, it is still possible to observe generated stress in all structures. However, the hybrid design was more efficient than the conventional design in reducing the displacement during the impact and consequently the stress on the upper teeth, lower teeth, and maxillary bone. Higher stress magnitude was more concentrated at the inner portion of the hybrid design than the conventional device. The HMG appliance decreased the stress concentration in the teeth and in the bone, limiting the areas susceptible to injuries to the regions directly impacted by the hockey puck. Although the novel HMG may mitigate injury, some stress will still result, and any possible injury should be evaluated by a dental professional.

Numerical analysis of thermo-fluid problems in 3D domains by means of the RBF-FD meshless method

The use of CAE (Computer Aided Engineering) software, commonly applied to the design and verification of a great variety of manufactured products, is totally reliant on accurate numerical simulations. Classic mesh-based methods, e.g., Finite Element (FEM) and Finite Volume (FVM), are usually employed for such simulations, where the role of the mesh is crucial for both accuracy and time consumption issues. This is especially true for complex 3D domains which are typically encountered in most practical problems. Meshless, or meshfree, methods have been recently introduced in order to replace the usual mesh with much simpler node distributions, thus purifying the data structures of any additional geometric information. Radial Basis Function-Finite Difference (RBF-FD) meshless methods have been shown to be able to easily solve problems of engineering relevance over complex-shaped domains with great accuracy, with particular reference to fluid flow and heat transfer problems. In this paper the RBF-FD method is employed to solve heat transfer problems with incompressible, steady-state laminar flow over 3D complex-shaped domains. The required node distributions are automatically generated by using a meshless node generation algorithm, which has been specifically developed to produce high quality node arrangements over arbitrary 3D geometries. The presented strategy represents therefore a fully-meshless approach for the accurate and automatic simulation of thermo-fluid problems over 3D domains of practical interest.