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Based on the established system of concrete-filled fiber-reinforced polymer (FRP) tube (CFFT) in civil engineering and construction industry, this research presents a novel fabrication method for freeform FRP formwork through an additive process of winding FRP fabric with industrial robots. Different from the filament winding or fused deposition modeling process in additive manufacture, large-scale formwork is fabricated with layered winding of FRP fabric and simultaneously applying fast cure epoxy resin in the proposed methods. It increases the fabrication speed and material efficiency compared with the typical fabrication process of FRP formworks, and achieved the geometry flexibility from the numerically controlled additive process. The fabrication methods are developed through a series of preliminary tests, exploring the appropriate fabrication parameters, such as the overlapping height of each layer, winding speed, and epoxy resin type. Two additional prototypes addressing geometrical flexibility are also fabricated. Based on the feasibility studies, the article discussed the potential application of this system on a double-skin tubular arch (DSTA) bridge and a tree-like topological optimized column as the future outlook of this method. As developed based on the established construction systems such as CFFTs and DSTAs, not only the proposed system is compatible with current structure and construction system, but it also benefits from combining an off-shelf material with a flexible and accurate programmable robotic process. This research contributes to the scope of additive manufacturing system by targeting the fabrication of nonuniform optimized large-scale structures.

Purpose The purpose of this paper is to evaluate the model of a rear pressure bulkhead with different design optimizations to meet the pressurized cabin requirements of an aircraft. Design/methodology/approach This paper presents the results of the static analysis of a dome-shaped rear pressure bulkhead model designed in Catia-v5. Numerical analysis of model meshed in hyper-mesh and solved using Opti-Struct for iterative design optimizations. Findings All the iterative models are analyzed at 9 Psi. Rear pressure bulkhead designed with L-section stringer shows better results than the model optimized with T-section stringer for the same thickness. The model optimized with L-shaped stinger also reduces the weight of the bulkhead without affecting the structural integrity. Practical implications It has been concluded in this paper that the selection of specific shapes of the stringers shows a significant influence on weight reduction. Originality/value This paper provides a topical, technical insight into the design and development of a rear pressure bulkhead. It also outlines the future development of dome-shaped rear pressure bulkhead.

COVID-19 is a global pandemic caused by the novel coronavirus. Although the surfaces pose a low risk of transmission, it is beneficial to use a handheld key-like device to avoid touching the surfaces, especially in public places. The present article reveals a novel design for a multifunctional handheld device, termed the COVID key. The proposed COVID key exhibits ten distinct features, viz. doorknob opener, pushing, pulling, forceps action, sharp edge, key chain, smartphone stand, and a linear and angular scale frequently used in daily life. Theoretical and computational analyses are carried out to check the validity of the design under different loading conditions resembling everyday use. Topological optimization is carried out to achieve the best stiffness-to-weight ratio. The final design is 3D printed in two different materials, ABS (acrylonitrile–butadiene–styrene) and PLA (poly-lactic-acid), using fused deposition based additive manufacturing. Testing and validation of the design are carried out with everyday actions. The COVID keys are distributed among a group of ten unbiased users. The user satisfaction score is recorded based on six basic metrics, viz. ease of use, size, strength, appearance, material and ease of carrying. A satisfaction score of 85% is reported, with ABS being the preferred material of choice.

Permanent magnet synchronous motors (PMSM) are widely used in various fields of application of electric drives of industrial enterprises. For each application of the electric drive, it is necessary to accept technical requirements, such as the maximum torque of the electric motor and the fulfillment of the required conditions for the strength characteristics of the rotor and stator.PMSM has a number of advantages over other types of engines. Asynchronous motors have developed resource rational energy efficiency, while synchronous motors are more energy efficient without modifications. PMSM have smaller weight and size parameters, which allows them to be used in a wider field of application, for example, in household appliances, robots and many other drives.TARGET. The aim is to develop a methodology for topological complex optimization of the engine design, based on a genetic algorithm.METHODS. The genetic algorithm is more accurate than traditional analytical methods, the method used in the analysis of AC machines, takes less time than the usual trial and error design procedure based on the finite element method. The main optimization criterion is an increase in torque while maintaining the mass of the most expensive material (permanent magnets). This feature is important for the manufacture of a designed engine in production.RESULTS. A program has been written in Python, which made it possible to carry out a comprehensive topological optimization for the engine under consideration.CONCLUSION. Topological optimization based on the method of modifying the rotor design using a genetic algorithm with the additions necessary for correct operation with synchronous motors is presented.

To design a new subperiosteal implant structure for patients suffering from severe Maxillary Atrophy that lowers manufacturing cost, shortens surgical time and reduces patient trauma with regard to current implant structures. A 2-phase finite-element-based topology optimization process was employed with implants made from biocompatible materials via additive manufacturing. Five bite loading cases related to standard chewing, critical chewing force, and worst conditions of fastening were considered along with each specific result to establish the areas that needed to be subjected to fatigue strength optimization. The 2-phase topological optimization tested in this study performed better than the reference implant geometry in terms of both the structural integrity of the implant under tensile-compressive and fatigue strength conditions and the material constraints related to implant manufacturing conditions. It returns a nearly 28% lower volumetric geometry and avoids the need to use two upper fastening screws that are required with complex surgical procedures. The combination of topological optimization methods with the flexibility afforded by additively manufactured biocompatible materials, provides promising results in terms of cost reduction, minimizing the surgical trauma and implant installation impact on edentulous patients.

A two-stage design method is proposed. The first step consists of topological optimization of the product and subsequent determination of its facet geometry. The second step is parametrization of part of the CAD model and parametric optimization by various methods—for example, in terms of the response surface or by a gradient procedure. In some cases, that permits refinement of the results of topological optimization.

This paper is dedicated to investigate the explicit Lagrangian topological optimization for stress-constrained problems with global and local volume constraints. In most of the works in the state of the art, the global volume constraints were chosen as the main constraint of the optimization formulation. However, in many of the industrial applications such as in automotive engineering, some packaging regulations may lead to local volume constraints which should be considered in optimization formulation. In this research, a low-dimensional explicit parametrization approach called moving morphable components is coupled with mathematical programming to solve the aforementioned problem. The large-scale stress constraint is handled with aggregation techniques. The results of this paper are presented in some famous benchmark problems with different local volume constraints. It is demonstrated that local volume constrained can be easily handled with this approach. The present approach can be more effective in solving real engineering problems with packaging constraints in comparison with the traditional methods.

In recent decades, computer technologies and software such as computer-aided design (CAD) have been actively developing. Thanks to this, modern machine-building enterprises increase the reliability and quality of their products while reducing their weight and complexity of manufacturing. In order to meet numerous requirements, leading companies are increasingly using topological optimization tools at various design stages. The use of this method for effective product design is growing rapidly, due to the continuously increasing computing power of computers and software capabilities. Modern software for topological optimization allows to design the shape of the part from scratch, setting only the conditions for fixing and touching surfaces, and also allows to improve existing structures by reducing their weight based on the set restrictions (equal strength with the original part, equal deformation, preservation of natural frequency, etc.). However, the result of topological optimization is often a complex spatial structure. Using the example of the Earring element, a topological optimization of the structure was performed to ensure that the strength requirements were met and that the minimum mass was obtained. As a result of optimization, the design of a reduced weight compared to the prototype is obtained. The results of the verification calculation showed the sufficiency of the values of the strength reserves of the final design of the Earring.

This article proposes a design method to minimize the compliance or maximize the fundamental natural frequency of continuum structures under thin feature and support structure constraints in additi...

In this paper, the numerical simulation approach for designing the landing gear strut for a light aircraft is presented. The problems of extension and compression of the landing gear, as well as its strength during landing, are considered. The application of the topological optimization method for determining the optimal landing gear strut shape is shown.

The results of applying topological optimization methods (ESO and SIMP) are presented in terms of accuracy and performance on an example of a real three-dimensional object (the upper beam of a column press used in rubber vulcanization). Two statements of the topological optimization problem are considered: minimization of material ductility with restriction on volume and minimization of volume with restriction on equivalent stresses. Engineering interpretations of optimized structures are proposed and the results of their comparison with the existing version of the beam are presented.

The equipment to realize the rotary forging technology is called the rotary forging machine. Compared with the common forging equipment, machine frame will bear a large torsion force in the working process, and the load in the forming process will eventually act on the rotary forging machine frame, and cause it to deform, thus affecting the rolling situation of the workpiece. Therefore, good frame performance is the premise to achieve stable rotary forging. The good performance of the frame is closely related to the structural design and structural optimization. However, at present, there are few researches on the overall optimization design of the rotary forging machine, and the lightweight technology has become the current trend. In the early manufacturing of low tonnage rotary forging machine, the lightweight design is not paid enough attention to, even if it meets the use performance, but the machine is bulky, which seriously reduces the utilization rate of materials and increases the manufacturing costs. In this paper, based on the existing rotary forging machine, the topological optimization of the main body of the rotary forging machine is carried out, and then the sensitivity analysis of the thickness of each component of the machine frame to the performance of the frame is studied, which provides the basis for the follow-up size optimization. Finally, the experimental verification is carried out, and it is found that the work pieces of the rotary forging are relatively good, which shows that the optimization scheme is reasonable and can be reduced on the premise of satisfying the performance weight, saving manufacturing cost.

Object and purpose of research. The paper studies ship structures. The purpose of this work is to develop recommendations for algorithmization and use of ANSYS tools for topological and parametric optimization of ship structures. Materials and methods. Modern methods of topological and parametric optimization of structures were used. Main results. An algorithm for optimal design of ship structures has been developed. Based on the comprehensive use of topological and parametric optimization methods and modern software products, its practical application is illustrated by examples of optimal grillage design as part of the hatch cover in dry cargo vessel and the joint of aluminum panels as part of the hull of high-speed vessel. Conclusion. The developed algorithm was designed to find optimal design solutions in designing marine equipment. It allows to significantly reduce the weight of the designed structure and increase its resource compared to the closest analogues. The algorithm is a generalization of the experience of topological optimization, which finds the most rational structural and power scheme under the action of specified loads. The use of shape optimization at the final stage of the developed algorithm leads to an increase in the resource of the designed structure.

The software for the topological optimization of parts with different constraints of the objective function, as well as for the generation and use of different types of lattice structures for filling the parts, is developed within the project Development of the Atlas of Standard Forms for Topological Optimization of Structures Formed by Selective Laser Melting and Their Production Verification (agreement with the Ministry of Education and Science, project no. 2016-14-579-0009-492) carried out by the National University of Science and Technology MISiS, State Scientific Center of the Russian Federation AO NPO CNIITMASH, the All-Russian Scientific Research Institute of Experimental Physics, the Ministry of Education and Science of the Russian Federation, and OAO Nauka i innovatsii (State Atomic Energy Corporation Rosatom). The article describes the methods and algorithms of topological optimization of structures with the displacement and stress constraints of the objective function developed for the basic version of the software.

Image-based Vehicle ReID methods have suffered from limited information caused by viewpoints, illumination, and occlusion as they usually use a single image as input. Graph convolutional methods (GCN) can alleviate the aforementioned problem by aggregating neighbor samples' information to enhance the feature representation. However, it's uneconomical and computational for the inference processes of GCN-based methods since they need to iterate over all samples for searching the neighbor nodes. In this paper, we propose the first Pseudo-GCN Vehicle ReID method (PGVR) which enables a CNN-based module to performs competitively to GCN-based methods and has a faster and lightweight inference process. To enable the Pseudo-GCN mechanism, a two-branch network and a graph-based knowledge distillation are proposed. The two-branch network consists of a CNN-based student branch and a GCN-based teacher branch. The GCN-based teacher branch adopts a ReID-based GCN to learn the topological optimization ability under the supervision of ReID tasks during training time. Moreover, the graph-based knowledge distillation explicitly transfers the topological optimization ability from the teacher branch to the student branch which acknowledges all nodes. We evaluate our proposed method PGVR on three mainstream Vehicle ReID benchmarks and demonstrate that PGVR achieves state-of-the-art performance.

In this paper, we propose to use a modified SIMP method to solve the problem of topological optimization of structures from multiphase materials, i.e., structures containing components from more than two different materials, which must be distributed in the best way to obtain the best structural characteristics using only one design variable. Most problems of topological optimization are concerned with only one material and void, although in some cases, it is of interest to have a look at the topology of structure with several phases of materials that is at the problems of topological optimization of the structure from multiphase materials. Nevertheless, most of presently known approaches to solve the problems of topological optimization of structures based on the multiphase materials involve introduction of additional design variables, thereby increasing computational costs. The paper, when solving the problem of topological optimization of structures from multiphase materials, uses a modified SIMP method to approximate the properties of materials. In this approach a material density is considered as an independent calculated variable and selected from a continuous range, then separated by discrete values of densities of each material phase. Other properties are considered as continuous functions of density. The proposed method does not involve introduction of additional variables for materials approximation and ensures a stable transition from one phase of material to another and non-dependence of estimated costs on the amount of materials under consideration. To demonstrate the simplicity and efficiency of the proposed solution, the paper gives the examples of solving topological optimization problems for various designs from multiphase materials. Due to its conceptual simplicity, the proposed method can be easily applied to any existing topological optimization problems. The examples described in the paper show that using this solution allows us to obtain reliable structures with improved mechanical characteristics, which can be used to solve real problems in designing and manufacturing of complex structures.

Object and purpose of research. The paper studies hull assemblies of high speed vessels. The work purpose consists in check of effectiveness of existing recommendations on assembles design and in searching for their optimal design using numerical methods of topological and parametric optimization. Materials and methods. A comprehensive approach with using numerical methods of structural topological and parametric optimization is applied. Main results. Based on the comprehensive use of topological and parametric optimization methods and up-to-date software products, new design of assemblies of aluminum panel butt joints operating in various service conditions as a part of high speed ships was developed instead of the one recommended by the Rules of Russian Maritime Register of Shipping. Conclusion. Use of the optimal design algorithm earlier developed by the authors permitted to develop new design of assemblies of aluminum panel butt joints. These assemblies have higher low cycle and high cycle fatigue strength indicators in comparison with the ones used presently in construction of high speed ships.

The article describes the vast experience of the Compressor holding company in creating compressor equipment for various industries. Existing methods for the development and manufacture of turbochargers are demonstrated using an example of a non-standard refrigeration compressor designed to operate on gaseous refrigerant R704. The data on the additive technologies mastered by leading foreign companies in the field of aviation and rocket science are analyzed for the manufacture of parts and assembly units using 3D printing with metal materials. The experience of applying topological optimization methods in aircraft and rocket science is considered. The conclusion is drawn on the applicability of topological optimization methods for creating turbocompressor elements together with 3D printing technology. A method is proposed for creating non-standard low-consumption turbochargers providing a reduction in material consumption and an increase in the strength of parts and assemblies, including the stages of design calculation, preliminary calculation, building a 3D model, phased topological optimization, verification of loads, verification of technology, manufacturing using 3D printing, 3D scanning to confirm compliance of the printed part specified geometric properties, verification of the part for compliance with mechanical properties

This article presents results of complex study based on new methods of designing and manufacturing of metal ship propellers. The original model of propeller was redesigned with help of topological optimization method. Using a static distribution of rated pressure, the parameters of the stress-strain state of the optimized version of the propeller were estimated by comparing its stress state with the initial cast version of the solid unit. The propeller with optimized structure has reliability characteristics close to the original solid version. Based on optimized 3-D model the controlling program for robotic LMD-method of manufacturing was created and propeller was built-up. The weight of optimized propeller is 20% less than original solid one. Control samples for destructive testing also were manufactured. The mechanical properties of samples are not lower than for cast and rolled metal. Based on the same conditions of manufacturing it could be supposed that strength properties of built-up propeller are almost the same to control sample.

We present the first report on automated micro-manipulation of zebrafish embryos using an electrothermally-actuated microgripper. A five-bar linkage compliant microgripper, driven by a V-shaped electrothermal micro-actuator, is designed based on topological optimization. The electrothermally-actuated microgripper is fabricated, tested, and then integrated into a robotic micromanipulation system. The semi-automated manipulation of a single zebrafish embryo, as well as a series of comparison experiments, is carried out. Experimental results demonstrate that the microgripper has reliable capability of picking, moving, holding and releasing the zebrafish embryo. Specifically, it performs fairly well in immobilizing and limiting the excessive deformation of the embryo. Finally, based on teaching, the whole process of zebrafish embryo microinjection is programed and performed automatically, thus demonstrating great strengths and performance of the microgripper in zebrafish embryo micro-manipulation.

International audience; Depending on the requirements, the design of a product may result in very different solutions. Topological optimization is a mathematical tool that can be used to obtain lighter parts without decreasing their stiffness. As the optimized part shapes are often too complex to be manufacturable, additive manufacturing is generally used. Usually, the topological optimization is performed on a single part. However, for a product, the decreasing of mass and inertia in each individual part has an impact on the loads applied onto all the parts of the system. Moreover, different paths can be used to optimize a product, e.g. optimizing all the parts simultaneously or part after part. Therefore, the aim of this paper is to propose, based on a case study, some optimization principles to find the best optimization path to design an additively manufactured product. In order to do this, the concept of topological optimization loops is first proposed. Then, several optimization paths are compared. In comparison with a usual single topological optimization, the proposed method leads to an additional gain in mass of up to 35% for the case study. Finally, some optimization principles are suggested to choose the most adapted path according to the designer objectives.

This paper presents the application of the topological optimization in plane elasticity problems applying the boundary element method (BEM) coupled with the evolutionary structural optimization (ESO) procedure by using initial stress fields as the new strategy to create cavities in the topological optimization domain. In this approach, in the domain region, where must be removed in the heuristic process, a stress field is added that is equal to and of opposite sign in the initial elastic stress formulation resulting in null domain stresses. Thus, a virtual cavity is created, avoiding the introduction of elements in the domain of the structure or other cumbersome strategy integrated in the formulation for considering the void region in BEM. The advantages of the present approach, as compared to other existing methods, are that, firstly, during the iterative process, there is no need to remesh and recalculate the boundary equations at each iteration once the introduction of the initial stress - to simulate each void region - is computed in the right-hand side vector of the final algebraic equation and, secondly, there is a significant reduction in the computational cost. Numerical examples are presented and compared to others available in literature, showing the robustness and efficiency of the proposed algorithm.

The design of topologically optimized structures is straightforward, although the main problem is really to derive the correct structure in each instance. During the development of structures for additive manufacturing in particular, saving weight is crucial because weight is proportional to cost.In this contribution firstly, different approaches to topological optimization are presented and discussed. While computer-assisted tools provide high accuracy and demand defined conditions, approaches utilizing a pen and paper can be conducted relatively quickly, although these only provide little guidance.Secondly, a new approach is presented which is advantageous with regard to effort and affordability, yet which maintains an accuracy of results. To support the designer, an artificial neural network is trained to adapt suitable Michell structures within a given design area. These structures depict optimal paths to conduct the loads through a component and provide guidance in designing an appropriate topology.Evaluation has demonstrated that this new approach is capable of supporting designers in achieving lightweight structures.

Topological optimization is the process of reducing part weight while respecting strength requirements. This paper focuses on its possible positive consequences for the machining process. The main aim is to carry out a survey to obtain knowledge that will be applied during the topological optimization of a milling tool. According to all the indicators, the efficient implementation of lattice structures into the milling concept has the potential to achieve a high level of innovation, since the functional weight reduction of the tool allows for higher dynamics of the cutting process. The modified rigidity of the milling cutter and vibration absorption can extend the life of the cutting edge, and such a milling tool would provide a competitive advantage on the tool market.

The ability of a metal to be subjected to forming processes depends mainly on its plastic behavior and, thus, the mechanical properties belonging to this region of the stress–strain curve. Forming techniques are among the most widespread metalworking procedures in manufacturing, and aluminum alloys are of great interest in fields as diverse as the aerospace sector or the food industry. A precise characterization of the mechanical properties is crucial to estimate the forming capability of equipment, but also for a robust numerical modeling of metal forming processes. Characterizing a material is a very relevant task in which large amounts of resources are invested, and this paper studies how to optimize a multilayer neural network to be able to make, through machine learning, precise and accurate predictions about the mechanical properties of wrought aluminum alloys. This study focuses on the determination of the ultimate tensile strength, closely related to the strain hardening of a material, more precisely, a methodology is developed that, by randomly partitioning the input dataset, performs training and prediction cycles that allow estimating the average performance of each fully-connected topology. In this way, trends are found in the behavior of the networks, and it is established that, for networks with at least 150 perceptrons in their hidden layers, the average predictive error stabilizes below 4%. Beyond this point, no really significant improvements are found, although there is an increase in computational requirements.

The combination of topology optimization (TO) and 3D printing has revolutionized the way components are designed and fabricated. In view of this, this manuscript presents a TO workflow considering the frame of a scooter. In particular, TO is employed to redesign the scooter frame based on a commercial one. The topologically optimized frame is then fabricated with stainless steel 316L utilizing the selective laser melting (SLM) method. In particular, technical obstacles encountered during the process and according solutions are recorded. Given the herein notes, readers who are working with the two technologies can anticipate the technical problems and deliver more effective solutions should any of them arise. Web of Science 13 7 art. no. 1201

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Computer Methods in Biomechanics and Biomedical Engineering on 2022, available online at: http://www.tandfonline.com/10.1080/10255842.2021.1943370. In-silico models applied to bone remodeling are widely used to investigate bone mechanics, bone diseases, bone-implant interactions, and also the effect of treatments of bone pathologies. This paper proposes a new methodology to solve the bone remodeling problem using one-dimensional (1D) elements to discretize trabecular structures more efficiently for 2D and 3D domains. An Euler integration scheme is coupled with the momentum equations to obtain the evolution of material density at each step. For the simulations, the equations were solved by using the finite element method, and two benchmark tests were solved varying mesh parameters. Proximal femur and calcaneus bone were selected as study cases given the vast research available on the topology of these bones, and compared with the anatomical features of trabecular bone reported in the literature. The presented methodology has proven to be efficient in optimizing topologies of lattice structures; It can predict the trend of formation patterns of the main trabecular groups from two different cancellous bones (femur and calcaneus) using domains set up by discrete elements as a starting point. Preliminary results confirm that the proposed approach is suitable and useful in bone remodeling problems leading to a considerable computational cost reduction. Characteristics similar to those encountered in topological optimization (TO) algorithms were identified in the benchmark tests as well, showing the viability of the proposed approach in other applications such as bio-inspired design.

Hybrid building constructions are used for exemplifying the active learning approach in developing the following research skills of the prospective scientist: identifying and tackling the scientific problem, investigating complex building constructions numerically and experimentally, estimating structural parameters, identifying the worst external impacts and improving the construction. The bending-active structure is used to illustrate that a conventional approach for dealing with a scientific problem may fail and nonstandard decisions should be provided. Numerical investigation is considered for identifying the worst impacts on the ribbed dome construction and for estimating structural parameters of the cable roof. Graphical approach is used. In terms of development of the professional skills, it is far superior to precise but convoluted analytical techniques. Topological optimization is exemplified with the ribbed dome. Having tried and analyzed a number of embodiments the researcher develops the skills in targeted improving of the construction. Laboratory investigation of the cable roof and the bending-active structure are considered. Combining the lab activity and digital technologies gives better outcomes for developing professional competences of the prospective researcher.

Permanent magnet machines with segmented stator cores are affected by additional harmonic components of the cogging torque which cannot be minimized by conventional methods adopted for one-piece stator machines. In this study, a novel approach is proposed to minimize the cogging torque of such machines. This approach is based on the design of multiple independent shapes of the tooth tips through a topological optimization. Theoretical studies define a design formula that allows to choose the number of independent shapes to be designed, based on the number of stator core segments. Moreover, a computationally-efficient heuristic approach based on genetic algorithms and artificial neural network-based surrogate models solves the topological optimization and finds the optimal tooth tips shapes. Simulation studies with the finite element method validates the design formula and the effectiveness of the proposed method in suppressing the additional harmonic components. Moreover, a comparison with a conventional heuristic approach based on a genetic algorithm directly coupled to finite element analysis assesses the superiority of the proposed approach. Finally, a sensitivity analysis on assembling and manufacturing tolerances proves the robustness of the proposed design method.

The application of topological optimization is currently considered one of the current trends. Because the shape of the components thus designed is the result of a design generated based on external influences acting on the model, their form can be considered almost optimal. For example, the extent of material savings resulting from shortening production cycles and reducing energy requirements is significant. Due to the way models are produced by layering the material in 3D printing, this technology makes it possible to get a little closer to the models&rsquo, optimal shape, for example, to produce prototype models for the production of injection moulds. The amazing amount of plastic and composite materials that this technology brings allows for a variable change in manufactured models based on requirements or external influences. These materials also include a group of materials and composite materials that are classified as biodegradable due to their composition. This fact, combined with the possibility of achieving the most optimal shape of components, contributes to reducing the environmental burden of such oriented production. This work presents the opportunities for modifying topological optimization outputs based on operating parameters and limits of additive production equipment fused deposition modeling (FDM). It gives the possibilities of using alternative ecological materials, their direct application, and the impact on creating models with the help of this technology. The final phase represents the result of the optimization process of the subsystem mechanism and the influence of the mechanical properties of biodegradable materials on the production process and the energy intensity of production. The aim of this work is to point out the fact and possibilities of using composite materials on a natural basis and their possible impact on reducing the environmental burden.

The development of new materials has always been strictly related to the rise of new technologies and progressively efficient systems. However, cutting-edge materials might not be enough to ensure the effectiveness of a given product if the design guidelines used do not favor the specific advantages of this material. Polymeric composites are known for their excellent mechanical properties, but current manufacturing techniques and the relatively narrow expertise in the field amongst engineers impose the challenge to provide the most suitable designs to certain applications. Bio-inspired designs, supported by thousands of years of evolution of nature, have shown to be extremely profitable tools for the design of optimized yet structurally complex shapes in which the tailoring aspect of polymeric composites perfectly fit. Bearing in mind the current but old-fashioned designs of auto-parts and vehicles built with metals with little or no topological optimization, the present work addresses how biomimicry is being applied in the mobility industry nowadays to provide lightweight structures and efficient designs. A general overview of biomimicry is made regarding vehicles, approaching how the use of composite materials has already contributed to successful cases.

Topology optimization is a technique which has proven to be a very crucial and effective tool in modification of the geometry of various mechanical or load bearing components. This technique has been used in aerospace, mechanical and civil applications to save material and reduce the overall mass of the component. There are various existing topology optimization algorithms which produce remarkable results, each algorithm is unique, and the results obtained are different. Implant dentistry has become a new area where topology optimization has found a good scope. The goal of modifying a dental implant is to improve the osseointegration and enhance its stability, hence when a topological optimization study is being performed on a dental implant these additional factors are necessary to be considered. The literature pertaining to the topology optimization employed in dental implants is limited and this study focuses on the available literature and other important aspects like selection of the optimization algorithm, bone density and manufacturing method which influence the topology optimization procedure when employed in the modification of dental implants.

Purpose: The purpose of scientific research is to develop a mathematical model for optimizing the stamp topology used in metal forming processes. In the work, it was necessary to determine the volume of the inner region of the stamp as the target optimization function, optimization variables, which are the skeleton, replacing the stamp topology.

The paper presents a topological optimization method based on the function “Birth and death of an element” in ANSYS Mechanical APDL. To confirm the adequacy of the considered method, models were tested. The optimization results using the developed method were compared with the optimization results using the “Topology Optimization” module, which is the part of the ANSYS Workbench, where the boundary conditions were identical. The test showed a good agreement between the optimization results by the proposed method and the optimization in the ANSYS Workbench module “Topology Optimization”.

International audience; The numerical approach of topological optimization allows determining the optimal distribution of the material in a given volume in the function of an objective. This approach has recently regained interest thanks to the development of additive manufacturing, which makes it possible to manufacture its resulting parts with complex geometries. In the biomedical field, this numerical approach can also improve the performance of medical devices. Most of the time, the objective of topological optimization is to maximize the stiffness of the considered part while reducing its mass or volume. For example, this criterion has been applied for the optmisation of craniofacial reconstruction prosthesis (Al-tamimi et al. 2017). Some studies have integrated biomechanical considerations in the form of geometrical constraints in taking into account anatomical areas to be avoided (Sutradhar et al. 2016).To our knowledge, no study considers the phenomenon of “stress-shielding” between the bone and the implant in its optimization process. In this work, the originality is the optimization approach which does not only consider the mechanical characteristics of the optimized part (such as its stiffness) but also the mechanical characteristics of the surrounding bone. Thus, it involves specifically taking into account the mechanical behavior of the surrounding bone to topologically optimize the geometry of the medical device and improve the load transfer between the bone and the implant. For that, a numerical simplified Finite Element (FE) model is developed in this paper with a simplified geometry to highlight the possibility of controlling the load transfer bone and implant.

Topological optimization can realize the optimization of the mass distribution in the whole objective domain. Compared with morphology and size optimization, it has a higher degree of freedom. In this work, the three-dimensional topological optimization based on piezoelectric materials was discussed. Using the Optimality Criteria, topology optimization was applied to the cantilever piezoelectric transducer. The structure optimization was realized with the voltage and stiffness as the multi-objective function. The corresponding codes are given to show the process of optimization. With 70% of the origin volume, the bi-objective optimization increases the global stiffness by 50.9% and the voltage by 30%. As the iteration process shows, the results of bi-objective optimization prove the value of additive mass at the bottom of the cantilever. This lays the foundation for future piezoelectric transducer structural optimization. Using only stiffness as the objective, the final objective increases inconspicuously. Bi-objective optimization shows its superiority. There are quite a few papers that research the combination of stiffness and voltage, and research which studies three-dimensionality is a point of innovation. Furthermore, this is also the first time a piezoelectric topology code has been shared.

This paper presents a new procedure for the building information modeling (BIM) characterization of structural topologies manufactured with plastic materials and fused deposition modeling (FDM) additive technology. The procedure presented here transforms the architectural geometry into an expanded three-dimensional model, capable of directly linking the topology of the plastic structure with the technological, functional and economic requirements for working in advanced construction 4.0 environments. The model incorporates a new algorithm whose objective is to recognize the topological surface of the plastic structural part obtaining in a fully automated way the FDM manufacturing time as well as the manufacturing cost. The new algorithm starts from the voxelized geometrical surface of the architectural model, calculating the manufacturing time from the full geometric path traveled by the extruder in a voxel, the extruder&rsquo, s speed, the print pattern and the layer height. In this way it is possible to obtain a complete digital model capable of managing and analyzing the plastic architectural object in an advanced BIM 4.0 environment. The model presented in this paper was applied to two architectural structures designed for a real urban environment. The final structural geometries have been obtained through topological processes in order to reduce the raw plastic manufacturing material and to improve the plastic structure strength. The architectural elements have been validated structurally by the means of numerical simulations, following the scenario of loads and boundary conditions required for the real project. The displacement maps point to a maximum value of 0.5 mm according to the project requirements. The Von Mises stress fields indicate maximum values of 0.423 and 0.650 MPa, not exceeding in any case the tensile yield strength of the thermoplastic material.

The optimization of sport equipment parts requires considerable time and high costs due to the high complexity of the development process. For this reason, we have developed a novel approach to decrease the cost and time for the optimization of the design, which consists of producing a first prototype by 3D printing, applying the forces that normally acts during the sport activity using a test bench, and then measuring the local deformations using 3D digital image correlation (DIC). The design parameters are then modified by topological optimization and then DIC is performed again on the new 3D-printed modified part. The DIC analysis of 3D-printed parts has shown a good agreement with that of the injection-molded ones. The deformation measured with DIC are also well correlated with those provided by finite element method (FEM) analysis, and therefore DIC analysis proves to be a powerful tool to validate FEM models.

Topological optimization (TO) is commonly used to design a part for additive manufacturing (AM), but rarely for entire systems including several parts. How can be optimized a mechanical system in which each optimized part changes the boundary conditions? A Design method called TOMS (Topological Optimization of a Mechanical System) has been developed to take into account the variation of the boundary conditions when optimizing parts. When the using TOMS method the loops are performed until the optimization converges. The object of this article is to propose a discussion on the quantification of this convergence based on a practical case study.

In this paper, it is used to simulate and analyze the telescopic boom structure of a bridge inspection vehicle by HyperWorks software, to solve the problem that the bridge inspection vehicle is heavier and the stability is slightly insufficient, due to the increase of operating parameters. According to the analysis results, it is carried out to optimize the boom by using topological optimization. Compared with the previous, the weight of the telescopic boom is reduced by 16%, the stiffness is increased by 5%, the strength is increased by 10%, and the stability of the whole vehicle is increased by 2.7%. The simulation results are in good agreement with the test results, which proves the safety and reliability of the optimization scheme.

A methodology for obtaining the optimal structure and distribution for the gradient properties of a material in order to reduce the stress level in a soldered joint was constructed. The developed methodology was based on a combination of topological optimization methods (the moving asymptotes method) and the finite elements method, it was first implemented to solve problems of optimizing soldered joints. Using the proposed methodology, a number of problems were solved, allowing one to obtain optimal structural characteristics, in which a decrease in stress is revealed. Designing compounds using this technique will provide more robust designs. The proposed technique can be applied to a wide class of practical problems.

The coreless microgenerators implemented in electromagnetic vibration energy harvesting devices usually suffer from power deficiency. This can be noticeably improved by optimizing the distribution of separate turns within the armature winding. The purposeful optimization routine developed in this work is based on numerical identification of the turns that contribute most to the electromotive force and the elimination of those with the least contribution in order to reduce the internal impedance of the winding. The associated mixed integer nonlinear programming problem is solved comparatively using three approaches employing surrogate models based on kriging. The results show very good performance of the strategy based on a sequentially refined kriging in terms of the ability to accurately localize extremum and reduction of the algorithm execution time. As a result of optimization, the output power of the system increased by some 300 percent with respect to the initial configuration.

Topology optimization is a widely used technique for deriving efficient structural layouts for components in many engineering fields. The optimization process deals with the definition of the optimal material distribution of single components subjected to specified loads and boundary conditions, in case made of different materials or with embedded regions corresponding to other components or actuators. In this paper, a novel topology optimization problem is proposed. The case of the concurrent topological optimization of two different components sharing a part of the design spaces is considered. The design problem represents a design situation in which more than one component has to be fitted in an enclosed space and each component has its own load carrying function. In the paper, the problem is solved by a numerical technique able to allocate the common part of the design space to each component. Inside the allocated space, the actual material distribution of the component is optimized by a standard topological optimization algorithm. Numerical examples are provided to show the potentialities of the method. A (simplified) practical design problem is also considered.

One of the main challenges for the aerospace industry nowadays lies in weight reduction of aircraft components without compromising their structural functionalities. With that goal, structural and topology optimization show up as a combination of design and modelling techniques. Based on the finite element method (FEM), component optimization consists of removing material which is dispensable, keeping proper functioning of the modelled part. The result is an optimized geometry, usually with a complex shape, which is possible to manufacture thanks to additive manufacturing (AM) technologies. In this paper, the topological optimization methodology has been used to redesign the following components: (1) a connector support of the VEGA space launcher, (2) a typical lever component from civil aircrafts and (3) housing part from fan cowl structures. In all of the cases, a significant weight reduction has been reached without major impact on their mechanical behaviour. Finally, components (1) and (2) were manufactured by laser beam melting (LBM) technology to demonstrate the possibility of the couple, optimization and AM concepts, as a way to improve the future aerospace structures.

Topology optimization is a mathematical approach that optimizes the layout for the given design constraints such as loading and boundary conditions so that the optimum design obtained performs its function. In different types of loading conditions such as single load or multiple load topological optimization result in the best use of a material for a body in given volume constraints. In topological optimization the structural compliance is minimized while satisfying a constraint on the volume of the structure. This paper represents the topological optimization of the fork-end (double eye) of a knuckle joint with the objective to reduce the mass of an existing fork-end of a knuckle joint of an automobile or locomotive by applying the optimization technique. Reducing the weight of an automobile part will result in the overall weight reduction of a vehicle, thus, its energy consumption demands decrease thereby improving its fuel efficiency. The topological optimization was done using a finite element solver, ANSYS. The ANSYS Parametric Design Language was employed for utilizing the topological optimization capabilities of the commonly used finite element solver ANSYS. Solid92 elements were used to model and mesh the fork end of the knuckle joint in ANSYS. The optimality criteria method was used for topological optimizing the fork end of a knuckle joint.