Comprehensive Design Method Research Articles

Structure-performance relationship and molecular structure optimization design of acid phosphate ester extractants

The extraction performance of acid phosphate ester extractants (PEEs) decreases significantly as the acidity of the aqueous phase increases. Therefore, finding PEEs suitable for high-acid environments has become critical to addressing their performance attenuation. However, the unclear structure-performance relationship of PEEs has led to a lack of guidance in experimental synthesis, significantly impeding the emergence of new acid-resistant PEEs. To tackle these issues, ten novel phenyl phosphate ester extractants were designed based on the molecular formula of phosphodiester (R1R2P(=O)OH) and the conjugation effect of the benzene ring. The relationship between the intrinsic extraction performance of acid PEEs and substituent groups (phenoxy, alkoxy, and alkyl) was quantitatively established by calculating the Gibbs free energy changes of three primary reactions (dimer dissociation, monomer acid ionization, and metal coordination) during divalent cobalt ion extraction. Additionally, the impact of different substitution sites (para, meta, and ortho) of the benzene ring on the extraction performance of acid PEEs was studied. The results indicated that introducing phenoxy groups into traditional acid PEEs (P204 and P507) can effectively enhance the extractants’ acid ionization ability and thermodynamic driving force. The extraction performance of acid PEEs is positively correlated with the number of phenoxy groups, and carbon chain substitution at the meta-position of the benzene ring is the most advantageous. By screening five low-toxicity and low-cost phenolic hydroxyl reagents currently available on the market, design a phenyl phosphate ester extractant ([(CH3)3CCH2C(CH3)2C6H4O]2P(=O)OH, P-4TO) that combines cost and performance advantages. Furthermore, the transition state theory was used to confirm the feasibility of preparing P-4TO, which provided a comprehensive theoretical research method for the future design and synthesis of efficient PEEs.

Multi-objective optimization design of automobile seat backrest considering coupling effect

To investigate the impact of the coupling effects of carbon fiber reinforced polymer in the seat back layer on the performance of car seats, this paper presents a comprehensive optimization design method for composite materials. In detail, the finite element models firstly established and validated through five typical working conditions of automotive seats based on experimental data. Then, the optimized variables are divided and determined through backrest stress nephograms for each working conditions of the automotive seats, in which the various perspective are taken into account, such as the total mass of seat backrest, safety performance, and comfort index. Subsequently, an optimization strategy for unequal thickness layers lay-up design is constructed, which combines strength factors, optimal Latin hypercube sampling, best-worst method, gray relational analysis, and Visekriterijumsko KOmpromisno Rangiranje method for the optimal design of the automotive CFRP seat backrest. Additionally, the impact of layer coupling effects on different performance indices of the seat is examined through simulating and analyzing the seat backrest with various layer coupling types, while incorporating the classical laminate theory. The study reveals that by minimizing the laminate coupling effect, the comfort of the seat can be enhanced. Finally, a comprehensive comparative analysis of the optimal trade-off solution is carried out in terms of optimization strategies. The results show that ensuring the safety performance, the total mass of the seat backrest decreased by 21.3%, as a result of the optimization strategy proposed in this paper, and the comfort performance is also improved to some extent. Therefore, the multi-objective optimization strategy proposed in this paper performs well in terms of effectiveness and provides a reliable reference for related composite material multi-objective optimization.

Comprehensive design method of controller parameters for three‐phase LCL‐type grid‐connected inverter based on D‐partition

AbstractThe LCL‐type inverter is a core component in grid‐connected renewable energy systems, with its performance heavily influenced by the controller. Conventional design methods of controller parameters generally rely on approximation or trial and error, making it difficult to optimize parameters for multiple performance indices. This paper proposes a comprehensive design method of controller parameters for a three‐phase LCL‐type grid‐connected inverter based on the D‐partition method, obtaining a multi‐objective parameter stability domain of controller parameters that simultaneously satisfies multiple performance indices, such as gain margin, phase margin, and current loop bandwidth. The stability domain can be visually presented, which can avoid repetitive adjustments. Additionally, the variation trend of the stability domain when there are deviations in the LCL filter parameters is analyzed. Finally, the accuracy and effectiveness of the proposed design method are validated through simulations and experiments, achieving precise parameter design for the controller of LCL grid‐connected inverters even in the presence of deviations in filter parameters.

Factor of safety analysis for mine pillar considering the influence of the intermediate principal stress component

Failure of mine pillars, especially in deep underground mines, significantly threatens the safety of miners and equipment. Previous studies on mine pillar stability design have used classical constitutive models that ignore the intermediate principal stress component when determining the factor of safety. In this study, we develop and implement a three-dimensional modified Hoek–Brown (HB) constitutive model that incorporates the intermediate principal stress component into the numerical simulation tool FLAC3D. Furthermore, we propose and apply a strength-reduction technique to determine a more accurate factor of safety for mine pillars. This novel approach provides a more comprehensive and realistic method for geomechanical analysis and pillar design, enhancing our understanding of pillar stability. Through numerical analysis, we illustrate the impact of the intermediate principal stress component on mine pillar plasticity. The factor of safety is calculated via the strength reduction method, revealing a substantial improvement from 1.7 with the classical HB model to 2.0 with the 3D HB model. Including the intermediate principal stress component reduces the evolution of plasticity in the mine pillar. For instance, the volume of plastic zones diminishes, and the factor of safety increases as the width-to-height ratio increases. Exemplary simulations show that ignoring the effect of the intermediate principal stress component, including underestimating safety levels, designing suboptimal pillar design, and misinterpreting in situ observations and measurements, can lead to severe consequences.

A Comprehensive Design Method for Multichip Double-Sided Cooling Power Module With Multidimensional Self-and Mutual Inductances

A Comprehensive Design Method for Multichip Double-Sided Cooling Power Module With Multidimensional Self-and Mutual Inductances

Pre-tension design and research of cable net structure for space modular deployable antenna

Modular deployable antennas represent an ideal structural form for the development of large-aperture antennas because of their flexibility, adaptability, and high versatility. To enhance the surface accuracy of the antenna after deployment, a comprehensive pre-tension design method that considers truss deformation and tension uniformity is proposed. First, the configuration design of the antenna cable net is constructed, and the mathematical models for cable length under surface accuracy requirements and boundary nodes are established considering catenary effects. Second, the distribution patterns of cable net structure nodes and segments are analyzed, leading to the creation of node coordinate matrices and cable net connection matrices. A basic model for cable net pre-tension design is developed based on the fundamental principles of force density. Furthermore, a multi-objective optimization of cable net pre-tension is performed using a genetic algorithm, considering truss structure deformation and tension uniformity as dual factors. Finally, the developed model is applied to design a single-module cable net structure, and numerical simulation is used for validation. Research results show that the overall surface form error is 0.32 mm, and the maximum tension ratio of cable net on the front cable net surface is 1.54, whereas the maximum tension ratio of tension ties is 2.28, thereby meeting the design requirements. Numerical simulation shows that the maximum deformation of the cable net structure is 0.16 mm, validating the correctness of the model. This research can provide valuable insights and references for the pre-tension design and research of cable net structures in other antennas.

Enhancing transmission type frame structures: A BBO algorithm-based integrated design approach.

The stable and site-specific operation of transmission lines is a crucial safeguard for grid functionality. This study introduces a comprehensive optimization design method for transmission line crossing frame structures based on the Biogeography-Based Optimization (BBO) algorithm, which integrates size, shape, and topology optimization. By utilizing the BBO algorithm to optimize the truss structure's design variables, the method ensures the structure's economic and practical viability while enhancing its performance. The optimization process is validated through finite element analysis, confirming the optimized structure's compliance with strength, stiffness, and stability requirements. The results demonstrate that the integrated design of size, shape, and topology optimization, as opposed to individual optimizations of size or shape and topology, yields the lightest structure mass and a maximum stress of 151.4 MPa under construction conditions. These findings also satisfy the criteria for strength, stiffness, and stability, verifying the method's feasibility, effectiveness, and practicality. This approach surpasses traditional optimization methods, offering a more effective solution for complex structural optimization challenges, thereby enhancing the sustainable utilization of structures.

Conceptual Configuration Analysis of Tetrahedral-Octahedral Heterogeneous Unit and Topological Design of Shape Morphing Mechanism

Abstract The truss static structure system has excellent large load and lightweight characteristics. It is easy to embed actuators by substituting specific members in the structure and has the potential for multidimensional space deformation. Inspired by uniform tessellation structures, this article proposes a novel shape morphing mechanism (SMM) based on the combined design of tetrahedral-octahedral heterogeneous units (TOHUs). The relationship between the motion properties and driving configuration of the tetrahedral-octahedral units is analyzed to determine their conceptual configuration based on graph theory. Then, the weighted graph, adjacency matrix, and connection rules are evaluated to synthesize the conceptual structure for the truss mechanism. The results show that this configuration can allow multidimensional continuous deformations, including span, bend, sweep, and twist. A prototype is built to verify its deformability. Finally, the stiffness performance is analyzed based on the matrix displacement method. This research provides a comprehensive design method for constructing SMM, expands the range of combinable units and connection methods, and offers theoretical guidance for the innovative design of multidimensional deformation SMM in aerospace.

Structural Optimization and Process Scheme of Large-span Gantry Crossbeam based on Response Surface

A comprehensive design method for large-span gantry beams, combining process techniques and structural optimization, is proposed to address significant deflection deformation issues caused by their own gravity and the gravity of front attachments. Selecting the beam section type, finite element static analysis is performed using ANSYS Workbench for both cast and welded gantry beams. The maximum static deformation values of the beams for both process schemes are compared to determine the process scheme for the large-span beam. Subsequently, multiple structural dimensions of the welded gantry beam are parameterized, and sensitivity analysis is conducted to determine the degree of influence of each parameter on the optimization objective. Parameters with relatively small effects on the corresponding objectives are eliminated. A response surface multi-objective genetic algorithm optimization based on Box-Behnken design experimental design method is employed to minimize deflection deformation and reduce weight. The response surface model is fitted with expressions, and variance and significance analyses are conducted to validate the model's reliability. The optimal Pareto solutions are determined based on the response surface model using a multi-objective genetic algorithm. A comparison between the beams before and after optimization shows a reduction of 0.052 in maximum static deformation of the welded beam, representing an 8.3% decrease. Additionally, the mass decreases by 1710 kg, indicating a 14.63% reduction, demonstrating significant optimization effects.

Comprehensive Flow Path Design Method for the Adaptive Cycle Engine Considering the Coupling Relation of Multiple Components

Abstract The adaptive cycle engine (ACE) has multiple coupled components on the same spool and complex bypass system, which makes it have more complex intercomponent coupling relation and hard to coordinate in the flow path design. In this study, the coupling relation of the ACE components and the component reference conditions are analyzed and determined, a multicomponent collaborative optimization design method is proposed to enable the quantitative evaluation of flow path design solutions. In this method, two optimization strategies are presented based on the different priorities of the intercomponent size coupling parameters, the intercomponent aerodynamic coupling parameter and the component performance in the optimization problem. ACE flow path solutions for various feasible design speed combinations are generated automatically considering the component performance and intercomponent coupling relation. According to an ACE flow path design case study, the design physical rotational speeds of low-pressure spool (NL,d) and high-pressure spool (NH,d) should be 7000 to 7600 r/min and 10,000 to 15,000 r/min, respectively. At NH,d = 12,000 r/min and NL,d = 7200 r/min, the high-pressure compression components and the fan components could be designed with the lowest aerodynamic load, respectively. NH,d is the key factor affecting the axial length of ACE. This method can be applied to other gas power plant designs.

Multi-scenario investment forecast of new energy projects based on multiple linear regression and comprehensive evaluation model of differentiated project priorities

As China's resource shortage and environmental pollution intensify, the demand for new energy and electric energy substitution is becoming higher and higher. Accurately predicting the investment scale of China's new energy projects is of great practical significance for improving the efficiency of resource allocation and economically meeting energy demand. This paper builds a scientific and precise investment model for new energy projects from both macro and micro perspectives. First, from a macro perspective, considering macro indicators such as the external environment and internal economy, an annual total investment forecast model based on multiple linear regression is constructed, in order to predict the annual total investment scale of new energy investment entities and achieve preliminary accurate investment; second, designed the evaluation index system of different project priorities from three perspectives of external environment, internal development of enterprises and social development, and constructed the comprehensive weight design method based on AN-EWM and the comprehensive evaluation method of TOPSIS, in order to realize the priority of differentiated projects. Sorting; finally, a new energy project located in a city in northern China is selected as the research subject, and a multi-scenario example analysis is carried out. The results show that the new energy project investment scale index system constructed in this paper can effectively evaluate the investment capacity of the main body of the new energy project, and can better predict the total investment of the new energy investment project, so that the deviation rate can be controlled within 5 %, and the priority evaluation model constructed in this paper can provide a complete calculation method and a reference method for the judgement of the investment priority, which can promote accurate investment.

Design optimization and experimental demonstration of a gravity-assisted cryogenic loop heat pipe

Cryogenic loop heat pipe (CLHP) is an efficient two-phase heat transfer device utilized for cooling electronic components within a cryogenic operating temperature range (3–220 K), such as an infrared detector and superconductive magnet. Compared with the prevalent cryogenic loop heat pipe which uses a capillary starter pump to achieve the startup, this research studied a gravity-assisted CLHP that uses gravity to achieve the startup. In this way, the configuration of gravity-assisted CLHP became simple, and the preconditioning could be achieved without consuming the extra heat load on the capillary starter pump. This proposed CLHP is intended for use in ground and space (in the gravitational environment such as the Moon and Mars). A comprehensive design method including the design optimization of the gas reservoir and compensation chamber (CC) volumes was newly established by considering the variation of vapor-liquid distribution in CC during the operating temperature range, resulting in a significant reduction of at least 40 % in the gas reservoir volume compared to conventional CLHP designs. Then the fabrication and the experimental investigation were implemented. Nitrogen was selected as the working fluid. The CLHP was designed to transport heat exceeding 20 W over a distance of 2 m within the operating temperature range of 80–110 K. Based on the experimental result, the startup was achieved, and the heat transfer performance satisfied the design requirement. Additionally, the detailed operating characteristics of the CLHP, including the gravity effect, the startup behavior, and the hysteresis phenomena that occurred in the temperature of the evaporator, pressure, and thermal resistance, were also first reported and thoroughly investigated.

A comprehensive design method of an active electronic current transformer for stable energy harvesting from power lines

AbstractThe real‐time monitoring technology of power line is an important guarantee for the digitization and intelligence of the modern power system. Traditional current transformers cannot provide continuous and stable energy when the power line current fluctuates in a large range. This paper proposes a comprehensive design method of an active electronic current transformer (AECT) based on a single‐phase full‐bridge voltage‐type PWM rectifier (VSR), which can acquire continuous and stable energy from the power line with a minimum magnetic core. The control of the AECT is divided into four different operation modes to adapt the fluctuation of primary current. Maximum power point tracking (MPPT) mode and minimum loss (ML) mode is designed to harvest the maximum power with lower iron core loss when the primary current is relatively low. Excitation mode and demagnetization mode are designed to harvest stable power when the primary current is higher than a certain current. The specific mode operation principles and control strategies are analysed in detail. Besides, the calculation method of the primary current is also presented for the primary current measurement. Finally, simulations and experiments verify that the iron core can obtain power steadily (9.91 W/kg) when the current fluctuation between 50 and 600 A.

Topology design and performance optimization of six-limbs 5-DOF parallel machining robots

The core components used in frontier fields typically have complex surface topography, difficult-to-remove workpiece materials, and extremely high machining quality and efficiency requirements. These characteristics pose major challenges to the performance of machining equipment. To address these issues, a class of six-limbs five degree of freedom (5-DOF) parallel machining robots with high stiffness and flexibility is designed. To cope with the coupling effect of multi-type parameters of robots on the optimal design, a comprehensive optimal design method combining mechanism theory and engineering experience is proposed. This method includes topology synthesis, layout evolution, performance design, and structure selection. Three performance indices, namely, stiffness, transmissibility, and mass, are considered. Two novel layouts and six novel prototypes have been optimized. Through the quantitative comparison and qualitative analysis of the above results, the influence of different layout and topology on the structure and performance of the robot is discussed, and several potential application scenarios are presented. The numerical simulation demonstrates that the designed six-limbed 5-DOF parallel robot exhibits satisfactory static behavior and flexibility, fulfilling the essential requirements for complex component machining.

A long period fiber grating seawater salinity sensor based on bend insensitive single mode fiber

In this work, we proposed a long period fiber grating (LPFG) seawater salinity sensor based on a bend insensitive single mode fiber (SMF). The average curvature sensitivity of LPFG in the most sensitive direction is 0.889 nm/m−1 in curvature range of 0 m−1–2.25 m−1. A comprehensive design method was proposed to optimize the sensitivity of seawater salinity by fully combining mode transition (MT) and reducing cladding diameter. The enhancing effects of MT and reducing cladding on surrounding refractive index (SRI) sensitivity were discussed, respectively. After reducing the cladding diameter by hydrofluoric acid (HF) etching, a layer of titanium dioxide (TiO2) nanofilm was deposited on the surface of LPFG by electrostatic self-assembly technology. The average seawater salinity sensitivity of 163.299 pm/‰ can be achieved in salinity range of 5.001 ‰–39.996 ‰. The experimental results are well agreement with theoretical analysis.

Analytical Fractional-Order PID Controller Design With Bode’s Ideal Cutoff Filter for PMSM Speed Servo System

In this article, a speed control scheme based on an analytically designed fractional-order PID with Bode’s ideal cutoff (FOPID-BICO) filter is proposed. The FOPID controller is designed to track the speed references and the BICO suppress is applied to filter the high-frequency noise. Considering the difficulty of parameters tuning of the FOPID controller, a comprehensive analytical design method based on frequency specifications-defined loop-shaping for the FOPID-BICO controller is first proposed for the permanent magnet synchronous motor speed control. The designed speed servo system satisfies five frequency-domain specifications: gain crossover frequency, phase margin, phase crossover frequency, gain margin, and a “flat phase” constraint. Moreover, the influence of phase crossover frequency on control system is fully exposed through the frequency-domain analysis. The proposed designed method ensures that the control system is robust to loop gain variations and guarantees the optimal performance on rejecting noise in high-frequency and disturbance in low-frequency. The effectiveness of the proposed FOPID-BICO controller has been verified by experimental results.

Optimization of Design Method and Experiment of A Repetition Pulse Charging HIA-CCPS

Due to the advantage of high-power density, high energy storage density and fast repetition pulse charging ability, homopolar inductor alternator (HIA) has been successfully applied in the capacitor charging power supply (CCPS) system, leading to a new capacitor charging power supply (HIA-CCPS) in recent years. To obtain a compact HIA-CCPS with high performances of light weight, small size, high repetition pulse output ability and so on, it is still of great necessity to develop quantitative analysis from alternators to the pulse load such as capacitors. Unfortunately, many researchers only focus on the alternator design or use a single charging process with constant speed instead of the repetition charging dynamic process with a large speed change for simplifying analysis. As a result, parameters' influence between alternators and others in the system is not clear, it is not easy to find out a system-wide optimal scheme. In this text, a comprehensive design method for HIA-CCPS with repetition pulse charging is proposed. Firstly, a simplified model is presented to analyze the influence of different parameters. The repetition pulse charging characteristics of HIA is investigated. After that, a novel design method of repetition pulse charging is given, and an excitation control strategy during the charging is put forward to ensure the charging time remains almost constant between each charging time. Finally, a platform of HIA-CCPS is developed and experiments are carried out. The experiment results indicate that the proposed method is very helpful for a repetition charging HIA-CCPS to develop the optimization design.

Mechanical properties and microstructure of ultra-high strength concrete with lightweight aggregate

In recent years, the development of concrete has been toward to the direction of lightweight and high strengthening. This study developed a kind of lightweight ultra-high strength concrete(L-UHSC) through the comprehensive design method, which had an apparent density rang of 1995 kg/m3-2114 kg/m3 and a compressive strength of 102.4–114.5 MPa. The specific strength of the designed L-UHSC is more than 50 MPa/(t/m3), which is higher than ordinary structural lightweight aggregate concrete (LAC). Additionally, the roles of high-performance paste, lightweight aggregate (LWA) and steel fiber in L-UHSC were revealed through scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and strength test. The findings revealed that SF content, rather than the binder-sand ratio and aggregate ratio, has a greater impact on density and strength, and the aggregate ratio having the least effect. As steel fiber content increases from 0.5 % to 2.0 %, compressive strength, flexural strength and splitting tensile strength of LAC increase by 44.3 %, 120 % and 151 %, respectively, which is higher than that of ultra-high performance (UHPC). The micromorphology and pore structure research suggested that the high-performance paste plays a keystone role in achieving the ultra-high strength, and LWAs mainly affected strength through improving pore structure. In addition, small size pre-wetted LWA is more conducive to concrete strength. Our preliminary results provide a reference for the research and development of lightweight ultra-high strength cement composites.

Design of branch line directional coupler for 5G millimeter wave communication

A directional coupler based on a microstrip branch line for 5G millimeter wave communication is designed. The branch line structure is simple and easy to implement. The comprehensive decomposition design method of the microwave system is proposed to improve the design efficiency. Based on the theoretical analysis of microwaves, the design method of combining automatic tuning and manual tuning optimization is used to optimize the schematic simulation. The layout simulation adopts iterative optimization to approximate the design index and reduce the influence of branch line connection loss. Finally, a millimeter wave branch line directional coupler is designed with a bandwidth of 24.25ghz to 27.5ghz, a coupling degree and insertion loss of about 5dB, and an isolation degree of more than 20dB. In the coming 6G, this design method has a certain forward-looking significance.

Analysis Method and Case Study of the Lightweight Design of Automotive Parts and Its Influence on Carbon Emissions

The automobile industry, as a representative in pursuing the goals of “emission peak” and “carbon neutrality”, has made low carbon a new industrial practice. With regard to low carbon, the lightweight design proves to be an effective approach to reducing carbon emissions from automobiles. Given the state of research, in which the existing lightweight design schemes of automobiles seldom consider the impact of the lightweight quality on carbon emissions during the whole life cycle of the automobiles, this paper proposes a more comprehensive lightweight design method for automobiles in regard to carbon emissions. First, the finite element method was adopted to analyze the stress, strain and safety factors of the automobile parts based on their stress, so as to identify the positions where the lightweight design was applicable. Subsequently, a lightweight scheme was designed accordingly. Next, the finite element method was re-applied to the parts whose weights had been reduced. In this way, the feasibility of the lightweight scheme was verified. In addition, a method of calculating the carbon emissions produced by changes in the mass, manufacturing processes, application and recycling of automobile parts after the application of the lightweight design was also presented. The method can be used for evaluating the low carbon benefits of the lightweight design scheme. To prove the feasibility of the method, the ZS061750-152101 wheel hub designed and manufactured by Anhui Axle Co., Ltd. was taken as an example for the case analysis. The lightweight design changes three structures of the wheel hub, reducing its weight by 1.4 kg in total. For a single wheel hub, the carbon emissions are reduced by 51.22 kg altogether. That is to say, if the lightweight scheme were to be applied to all the wheels produced by Anhui Axle Co., Ltd. (about 500,000 per year), the carbon emissions from the wheel production, application and recycling could be cut by 2.56 × 107 kg, marking a favorable emission reduction effect. The proposed method can not only provide insight into the lightweight design of automobiles and other equipment against the background of low carbon but also provide a channel for calculating the carbon emission changes in the whole process after the application of the lightweight design.