Minimum Material Consumption Research Articles

GEOMETRIC OPTIMIZATION OF A NANOSTRUCTURED W-SiO2-W SELECTIVE EMITTER WITH TEMPERATURE DEPENDENT EMISSIVITY FOR THERMOPHOTOVOLTAIC APPLICATIONS

Metal-Insulator-Metal (MIM) nanostructures provide tunable multiple absorption/emission peaks desirable for spectroscopy, light sensing and thermophotovoltaic (TPV) applications. The efficiency of TPV systems can be improved by employing MIM emitters with resonators that allow high emission above PV cell bandgap and low emission elsewhere. Although there have been attempts to design MIM emitters for TPV systems, a comprehensive study that investigates and optimizes different resonator shapes is lacking. In this study, broadband TPV emitters with W-SiO2-W nanostructures are optimized for pairing with GaSb PV cells. A numerical approach is followed utilizing finite-difference time-domain method and particle swarm optimization scheme, MIM emitters with four resonator shapes: disk, square, pyramid, and cone are dimensionally optimized to attain an emissivity spectrum that overlaps with high quantum efficiency region of the GaSb cell. The optimized emitters are compared for efficiency, power output, material consumption, as well as their optical response to temperature and angular effects. At an emitter temperature of 1600 K, electrical power outputs of 2.335-2.418 W·cm-2 and spectral efficiencies of 56.2-57.6% are obtained. It is found that flat resonators tend to achieve similar performance to that of pointy resonators with shorter heights. Among the considered shapes, disk emitter demonstrates the highest efficiency with minimum material consumption. Compared to a plain W emitter at the same temperature, the disk MIM emitter exhibits significantly higher spectral efficiency and electrical power output (34% and 215% respectively). The results demonstrate the successful use of nano-elements in TPV systems, and the potential for fabricating and realizing such structures.

Solving One-Dimensional Cutting Stock Problems with the Deep Reinforcement Learning

It is well known that the one-dimensional cutting stock problem (1DCSP) is a combinatorial optimization problem with nondeterministic polynomial (NP-hard) characteristics. Heuristic and genetic algorithms are the two main algorithms used to solve the cutting stock problem (CSP), which has problems of small scale and low-efficiency solutions. To better improve the stability and versatility of the solution, a mathematical model is established, with the optimization objective of the minimum raw material consumption and the maximum remaining material length. Meanwhile, a novel algorithm based on deep reinforcement learning (DRL) is proposed in this paper. The algorithm consists of two modules, each designed for different functions. Firstly, the pointer network with encoder and decoder structure is used as the policy network to utilize the underlying mode shared by the 1DCSP. Secondly, the model-free reinforcement learning algorithm is used to train network parameters and optimize the cutting sequence. The experimental data show that the one-dimensional cutting stock algorithm model based on deep reinforcement learning (DRL-CSP) can obtain the approximate satisfactory solution on 82 instances of 3 data sets in a very short time, and shows good generalization performance and practical application potential.

Novel Concrete Bridge Design : As Simple as Possible, but not Simpler

The paper discusses the need for a simplified and low-maintenance building culture to address global climate change. A transition to a circular economy, giving priority to efficiency rather than quantity is important. Creating structures with minimum material consumption and minimum maintenance with a maximum of recyclability should be our focus. Integral bridges such as the Duke’s Bridge in Germany and the Isarsteg-bridge in Munich are innovatively designed while taking into consideration the soil-structure interaction and the temperature induced stresses in structural detailing. The paper also considers additional technical aspects, such as the calculation of the mobilised earth pressure and the relevant deformations. Finally, a holistic approach that aligns with principles of resource efficiency, simplicity, and sustainability is suggested.

Development of 187Re targets for heavy ion induced reactions

To perform nuclear reaction experiment, very good quality, uniform and thin targets are necessary. In order to carry out evaporation residue cross section measurement of 19F+187Re reaction using Hybrid Recoil mass Analyzer (HYRA) facility at Inter - University Accelerator Center (IUAC) 187Re targets of thickness 200 μg/cm2 are required. More than 20 targets of 187Re of 200 μg/cm2 thickness with thin carbon backing have been prepared using 70 mg of 187Re. Being one of the highest melting points of all elements, high temperature involved in the process and limited amount of available isotopic material are the major constraints during the target development of 187Re. The targets have been successfully used for the nuclear reaction experiment. The method used for the development of several 187Re targets with minimum material consumption and the detailed characterization techniques applied for studying the targets are discussed in detail.

ВИЗНАЧЕННЯ ОПТИМАЛЬНОГО КРОКУ БАЛОК ДОЩАТОГО ПЕРЕКРИТТЯ

The article presents the results of optimization of the beams step of the building wooden floor according to the criterion of the minimum material consumption. The slab consists of parallel wooden beams of rectangular cross-section, on which the boardwalk is laid.

Fabrication and Characterization of the self support enriched 107, 109Ag thin targets for heavy ion induced transfer reaction

The enriched, self-supported, and thin isotopic targets of 107Ag and 109Ag were fabricated at the target development laboratory, IUAC New-Delhi, using a vacuum deposition facility. The targets were fabricated by the thermal evaporation technique with minimum material consumption. The simple and efficient method for the fabrication of thin targets with high quality without major impurities was discussed in detail. The prepared targets were characterised by using Rutherford Backscattering Spectrometry, X-Ray Diffraction, Total-Reflection X-Ray-Fluorescence and Scanning-Electron-Microscope techniques. From the characterizations, it was found that the fabricated targets were quite stable, had the same crystalline nature, the absence of any other elements, and were suitable for nuclear reaction experiments.

Sustainable design guidelines for additive manufacturing applications

PurposeAdditive manufacturing (AM) technologies have tremendous applications in industries owing to their unique advantages. Sustainable AM (SAM) is gaining significance because of lightweight structures, lattice geometries and customized parts for industrial applications. To facilitate design for SAM, design guidelines from AM and environment viewpoints are to be analyzed. In this context, this paper aims to present the analysis of SAM guidelines.Design/methodology/approachThis work divides 26 identified SAM guidelines into four categories. Grey axiomatic design was used to calculate the weights of guidelines categories. Further, the grey technique for order preference by similarity to ideal solution was used as a solution methodology to prioritize the SAM guidelines.FindingsThe top identified guidelines are “Design for reusability” and “Optimize part orientation for build time and roughness.” Implementing proper design guidelines leads to many sustainable benefits such as minimum material consumption, energy consumption and emissions.Originality/valueThis study would facilitate Am product designers to deploy prioritized guidelines for enhancing the effectiveness of the additively manufactured product with sustainability benefits. The prioritized guidelines would guide the AM product designers to take maximum advantage of the AM process by deploying design for AM and design for environment guidelines. This study contributed a structured approach for design engineers and practitioners to deploy guidelines during the early stages of product design to ensure AM feasibility with minimal environmental impact.

Investigation of wear properties of 3D-printed PLA components using sandwich structure – A review

In addition to traditional production methods, additive manufacturing (AM) is currently a popular technology to manufacture complex parts with minimum material consumption. This technology aids a range of businesses in meeting healthy market competition between the manufacturing sectors. AM technology can easily create parts that are difficult to fabricate using traditional methods. However, in every business, machine functions are dependent on the strength of individual pieces, which is determined by materials and manufacturing procedures. AM (additive manufacturing) is a revolutionary technique that allows us to create complex parts in a short amount of time. Several machine control parameters influence the AM process to produce any parts. These control parameter, material, and procedures have an impact on all mechanical and tribological properties of AM manufactured parts. The tribological property, out of all the mechanical properties, is a critical factor for all types of fabricated moving parts in the automotive sector. All machine control parameters, materials, and manufacturing procedures must be thoroughly examined before producing the wear-resistant mechanical part using additive manufacturing methodology. Fusion deposition modeling (FDM) is the most widely used one of the ASTM standard technologies from the seven methods additive manufacturing technology, and this article aimed to review all of the aspects that drive FDM component creation. Poly Lactic Acid (PLA) is an essential material in AM, and this article reviews current strategies for improving FDM printed parts to improve the wear characteristics. From the review, it was found that the use of composite material in FDM machines enhances the tribological strength of printed components above tribological improvement by altering machine control parameters. The wear strength of 3D printed specimens is improved by the uniform distribution of composite material in the feedstock filament.

Optimized Unidirectional and Bidirectional Stiffened Objects for Minimum Material Consumption of 3D Printing

3D printing, regarded as the most popular additive manufacturing technology, is finding many applications in various industrial sectors. Along with the increasing number of its industrial applications, reducing its material consumption and increasing the strength of 3D printed objects have become an important topic. In this paper, we introduce unidirectionally and bidirectionally stiffened structures into 3D printing to increase the strength and stiffness of 3D printed objects and reduce their material consumption. To maximize the advantages of such stiffened structures, we investigated finite element analysis, especially for general cases of stiffeners in arbitrary positions and directions, and performed optimization design to minimize the total volume of stiffened structures. Many examples are presented to demonstrate the effectiveness of the proposed finite element analysis and optimization design as well as significant reductions in the material costs and stresses in 3D printed objects stiffened with unidirectional and bidirectional stiffeners.

3D-Printed Biodigital Clay Bricks.

Construction materials and techniques have witnessed major advancements due to the application of digital tools in the design and fabrication processes, leading to a wide array of possibilities, especially in additive digital manufacturing tools and 3D printing techniques, scales, and materials. However, possibilities carry responsibilities with them and raise the question of the sustainability of 3D printing applications in the built environment in terms of material consumption and construction processes: how should one use digital design and 3D printing to achieve minimum material use, minimum production processes, and optimized application in the built environment? In this work, we propose an optimized formal design of “Biodigital Barcelona Clay Bricks” to achieve sustainability in the use of materials. These were achieved by using a bottom-up methodology of biolearning to extract the formal grammar of the bricks that is suitable for their various applications in the built environment as building units, thereby realizing the concept of formal physiology, as well as employing the concept of fractality or pixilation by using 3D printing to create the bricks as building units on an architectural scale. This enables the adoption of this method as an alternative construction procedure instead of conventional clay brick and full-scale 3D printing of architecture on a wider and more democratic scale, avoiding the high costs of 3D printing machines and lengthy processes of the one-step, 3D-printed, full-scale architecture, while also guaranteeing minimum material consumption and maximum forma–function coherency. The “Biodigital Barcelona Clay Bricks” were developed using Rhinoceros 3D and Grasshopper 3D + Plugins (Anemone and Kangaroo) and were 3D printed in clay.

OPTIMIZATION OF FUSED DEPOSITION MODELING PROCESS PARAMETERS FOR MATERIAL CONSUMPTION AND MANUFACTURING TIME

This paper aims to explore the effect of layer thickness, infill density and build orientation on the material consumption and manufacturing time of specimens printed by the fused deposition modeling process. Specimens in accordance with ASTM Standards were printed by varying the process parameters such as layer thickness, infill density and build orientation. Time required to manufacture the part and amount of material consumed during the process are recorded. Increase in infill density results into increase in material consumption and manufacturing time. Layer thickness and build orientation also impacts manufacturing time and material consumption respectively. With increased application of FDM process, determining the process parameter to decrease the material consumption and manufacturing time shall help the FDM practitioners globally. Present work elucidates the optimization of FDM process parameters to achieve minimum material consumption and manufacturing time.

Об одной задаче оптимизации конструкций с учетом требований устойчивости, прочности, при ограничениях первой частоты собственных колебаний

В одной из предыдущих работ авторов данной статьи рассматривалась задача оценки близости решения к проекту минимальной материалоёмкости при оптимизации ширины полок стержней двутаврового поперечного сечения при ограничениях по устойчивости или величины первой частоты собственных колебаний с учётом требований прочности в случае непрерывного изменения варьируемых параметров по длине стержня. При этом известно, что в строительной практике в основном стержни проектируются с кусочно-по­стоянным изменением параметров сечения. В другой статье авторов был сформулирован критерий оценки оптимальных решений при формирования кусочно-постоянных участков полки стержней двутаврового сечения при ограничениях по устойчивости или величине первой частоты собственных колебаний, но без учёта требований прочности. В данной статье рассматривается задача оценки оптимальных решений при формировании кусочно-постоянных участков ширины полок стержней двутаврового сечения при ограничениях по устойчивости или величины первой частоты собственных колебаний, но с учётом требований прочности и некоторых конструктивных ограничений.

Integral assessment of stress-defomated condition of metal structures of machines under the action of static and dynamic loads

The article considers a system that combines the influence of static on dynamic loads on the example of the support-rotary circuit of a truck construction crane. The position of the system and its elements with the highest loads is revealed, the method of creating steel structures is investigated, each element, depending on the average load, experiences a stress-strain state. The basic laws of the theory of elasticity and plasticity were used to build a calculated mathematical model of the loaded support-rotary circuit. Equations of motion were compiled taking into account the behavior of structural elements and the machine as a whole under the simultaneous action of different loads. The calculation scheme was taken in the form of a structure consisting of rods rigidly connected to each other in nodes. As a method of calculation the method of finite elements with definition of displacements (deformations), efforts (stresses) in nodes of a grid of constructive elements of a design of a basic-rotary contour is applied. The stress distribution in each structural element depending on the type of load was obtained. This distribution allowed to choose rational parameters of a design in each its section. The proposed approach allowed to create a solid structure that provides reliability and economy of material. Thus, the results obtained allowed to fully analyze and decide on the simultaneous provision of strength, rigidity and minimum material consumption of the structure.

Architectural form finding in arboreal supporting structure optimisation

Sustainable Development Goals have become a key factor in the design in the twenty-first century. The relationship between the architectural and structural systems is becoming a matter of relevance for sustainable design. The search for minimum material consumption can be seen by drawing inspiration from the solutions found in Nature. The high efficiency of natural forms, has become a contribution to research on tree-like structures. The purpose of the research was to identify the main aspects of arboreal supporting structures shaping and optimization at the early state of design. The methodology is to optimize the geometry of dendriforms, based on optimizing the shape of the bending moment diagram and adjusting it to the shape of the final bar structure. The primary conclusion of the studies indicates that the structural and architectural optimization, implemented in an early stage of designing might significantly improve material consumption without substantial changes in architectural appearance.

Thermo-economic analysis of a novel parabolic trough solar collector equipped with preheating system and canopy

This paper presents a novel Parabolic Trough Solar Collector (PTSC) equipped with a preheating system and canopy. The thermal, hydraulic, and economic characteristics of the PTSC are numerically investigated to achieve maximum performance evaluation criteria (PEC) index and minimum material consumption for different volume fractions of nanoparticles at various Reynolds numbers. The PTSC is also compared with a reference system without preheating system and canopy. The results indicate that preheating system does not have an obvious effect on friction factor of solar collectors. The PEC index values of the novel system are about 53.0% higher than those of the reference system. Besides, using canopy may have a crucial impact on the improvement of collector efficiency. According to thermo-economic analysis, the length of the PTSC is smaller than that of the reference system when their energy efficiency is the same, leading to lower production costs. It is found that the consumption of stainless steel and carbon steel decreases about 14% and the consumption of glass and carbon steel increases about 6% for the glass coverage and canopy.

Estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements

The previous research described estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements in continuous change in variable rod parameters. It is however known that in construction, rods are generally designed with piecewise constant change in the section parameters. Besides, in another work, the criterion was formulated for assessment of optimum solutions of piecewise constant sections of I-rods with stability or the first eigen-frequency limits, without considering the strength requirements. This paper focuses on a more general problem of estimated closeness of optimum piecewise constant section width in I-rods with stability or first eigen-frequency limits to the predicted minimum material consumption with regard to strength requirements.

Assessment criterion for optimum design solutions of piecewise constant sections in I-rods with stability or first eigen-frequency limits

The criterion for the minimum material consumption of strips strengthening the I-rod with stability or first eigen-frequency limits is formulated in previous studies for the case of continuous change of the variable parameter. It is known that this solution allows evaluating a real design project not only by the criterion of its proximity to the minimum material consumption, but also by the reference point in the real design. In many cases, it is used to replace the continuous change in the variable size of the rod-strengthening piecewise constant sections. The boundaries of these sections are based on the minimum material consumption. The width of the strengthening strips is determined by the optimization methods. The paper proposes the criterion allowing to correctly assess the termination of the optimization processes.

ОПТИМИЗАЦИЯ РАЗМЕРОВ СОСУДОВ ИЗ УСЛОВИЯ МИНИМАЛЬНОЙ МАТЕРИАЛОЁМКОСТИ КОРПУСА

. The method of optimization of tank sizes for minimum material consumption is considered. The dependences of the optimal diameter, height and weight of the tank body on the volume are obtained.

ASSESSMENT CRITERION FOR OPTIMUM DESIGN SOLUTIONS OF PIECEWISE CONSTANT SECTIONS IN RODS OF RECTANGULAR CROSS-SECTION WITH STABILITY OR FIRST EIGEN-FREQUENCY LIMITS

Specific properties of optimum systems have been already considered in previous research. Moreover, the criteria were proposed for a correct assessment of proximity of optimum to minimum material consumption. In particular, the criteria are proposed for rods of rectangular crosssection with stability or first eigen-frequency limits. These criteria can be used for problem optimization, when the rod cross-sections continuously change longitudinally. The obtained optimum solutions can be considered as a perfect limited object. This optimum project function allows researcher to assess the real design solution using the proximity limit criterion (for example, material consumption limit). This kind of optimum design can also be used as a guideline for real design in terms of a stage-by-stage process of transition from a perfect to real object. In this case, it is possible to assess changes in the object optimality at each stage as compared to the initial and idealized solutions. In particular, one of the variants of the process includes replacing the rod with continuous longitudinally varying cross-sections by a rod with piecewise constant sections. The section boundaries can be based on a perfect object, and cross-sections can be determined by one of the optimization methods. This paper presents criteria, which ensure the reliable definition of the time of completion of the optimization process.

ASSESSMENT CRITERION FOR OPTIMUM DESIGN SOLUTIONS OF PIECEWISE CONSTANT SECTIONS IN RODS OF I-SHAPED CROSS-SECTION WITH STABILITY OR FIRST EIGEN-FREQUENCY LIMITS

Specific properties of optimum systems have been already considered in previous research. Moreover, the criteria were proposed for a correct assessment of proximity of optimum to minimum material consumption. In particular, the criteria are proposed for rods of rectangular crosssection with stability or first eigen-frequency limits. These criteria can be used for problem optimization, when the rod cross-sections continuously change longitudinally. The obtained optimum solutions can be considered as a perfect limited object. This optimum project function allows researcher to assess the real design solution using the proximity limit criterion (for example, material consumption limit). This kind of optimum design can also be used as a guideline for real design in terms of a stage-by-stage process of transition from a perfect to real object. In this case, it is possible to assess changes in the object optimality at each stage as compared to the initial and idealized solutions. In particular, one of the variants of the process includes replacing the rod with continuous longitudinally varying cross-sections by a rod with piecewise constant sections. The section boundaries can be based on a perfect object, and cross-sections can be determined by one of the optimization methods. This paper presents criteria, which ensure the reliable definition of the time of completion of the optimization process.