Structural Optimization Analysis Research Articles

Structure optimization and exergy analysis of a two-stage TEC with two different connections

This paper develops three dimensional numerical models of a two-stage series-connected TEC model and a two-stage parallel-connected TEC model. NSGA-II is used to optimize their electric current, height of lower stage and ratio of channel width and thickness of fin in the case of constant thermoelectric material volume. Two objectives, exergy efficiency and irreversibility are considered simultaneously. The optimal values one Pareto front are obtained by three decision making methods, Shannon’s entropy, TOPSIS and LINMAP, while deviation index is a criterion for evaluating three decision making methods. Sensitive analysis has been carried out to investigate the influence of three variables to be optimized. And TEC with and without plate-fin heat exchanger have been compared. The results show that solution selected by LINMAP is the most compromising solution. The parallel connected TEC saves about 50% of the power consumption compared to the series connected TEC under the same temperature difference. Optimal variables are discussed to obtain the most energy efficient solution with optimal configuration and plate-fin heat exchanger.

Analysis and Optimization of a Cyclone Integrated with a Cartridge Filter in a Hazardous Materials Collection Truck

In order to meet the filtration separation of hazardous materials on hazardous materials collection truck, the most popular separation devices, such as the cyclone separator and the filter cartridge, are combined to form a new filtration device in this study. The advantages of the two devices are utilized to achieve effective separation of solid particles and prevent secondary pollution. Among the various structural influence factors of filtration equipment, four structural parameters that affect the separation performance significantly are selected as optimization variables. The response surface methodology was used to design the simulation experiment. Using fluid mechanics analysis software, multiple sets of parameters were simulated. Then, the simulation data was used to establish a mathematical model of separation efficiency, and structural optimization analysis was performed based on the mathematical model. Finally, the results show that the inner exhaust pipe diameter and the cone height have more influence on the efficiency of the cyclone separation structure. The interaction between the diameter and insertion depth of the inner exhaust pipe is also obvious. Among the four optimization variables, there is an optimum value for the inner exhaust pipe insertion depth, and the effect of the other three factors on the separation efficiency is monotonic. In the case of a total separation efficiency of 99.9% and after optimizing the combined model within a reasonable interval, 81.25% of the 1-μm particles can be removed by the cyclone separation part, and only 18.75% are removed by the filter cartridge.

Analysis for Stress Characteristics and Structural Parameters Optimization in Orthotropic Steel Box Girders based on Fatigue Performance

A fatigue design method for the orthotropic steel deck bridges is proposed. The stress characteristics of welded details are analyzed using the finite element method. Based on the fatigue performance, the structural parameters of the orthotropic steel decks (OSDs) are optimized using the combination BP (back propagation) neural network and genetic algorithms (GA). The calculated results demonstrate that the weld stresses at the deck plate-to-rib, deck plate-to-rib-to-diaphragm welded details are mainly bending stress while those at the rib-to-rib welded details are mainly membrane stress. The fatigue stress of each weld is deeply affected by the transverse and longitudinal direction positions. The local effect of stress distribution of all welded details is remarkable. The calculated results obtained using the proposed model are in good agreement with those obtained using ANSYS and the errors are within 5%. The optimal structural results are highly influenced by the applied wheel loadings, while the optimal results for the deck thickness and the U-rib opening size are highly influenced by temperature. Especially on the ordinary lane, temperature has a great effect on the fatigue performance for all welded details.

Structural Parameter Optimization and Performance Analysis of Autonomous Inflow Control Device

The Autonomous Inflow Control Device (AICD) adjusts the inflow of the horizontal wellbore by adding additional resistance to the fluid, thereby prolonging the water seepage time and enhancing oil recovery. The performance of AICD mainly depends on structural parameters. The computational fluid dynamics software is used to analyze the influence of structural parameters on the performance of AICD. The results show that the diameter of the variable diameter section, the diameter of the restrictor and the diameter of the outlet are the main factors affecting the performance of the inflow control device. The fluid parameter sensitivity simulation results show that the oil phase viscosity and water content have a great influence on the performance of AICD, while the influence of oil phase density on the performance of the device is negligible; the pressure drop under the pure water condition of this type of AICD is more than twice that of pure oil condition, so it has better water control ability.

The improvement study for global and local cooling of servers

Cooling of server is getting more attention these years, which directly influence the efficiency of data processing, storage, and telecommunication. In order to solve the hot issues of sever, a thermal simulation model was built. Finding that the hotspots were mainly concentrated in CPU and Northbridge chips. With regard to CPU, the structure optimization analysis of CPU heat pipe radiator was carried out without changing the volume of heat pipe radiator. The fin thickness and fins number of heat pipe radiator were optimized. The optimized radiator could reduce the CPU hotspot temperature by 5.3%-9.09%. With regard to North Bridge chip, a chip-level cooling method based on Peltier effect was proposed. The cooling performance of thermoelectric cooler was investigated by experiments, and the best working current under different wind speed and cooling load was explored. Compared with the original heat dissipation method (non-thermoelectric cooler), the thermoelectric cooler could improve the starting characteristics and response characteristics of heat dissipation radiator, and the added thermoelectric cooler could reduce the temperature rise of North Bridge chip by 4.45%-31.12%.

Genetic Algorithm-Based Structure Optimization and Load-Carrying Analysis for the Body Frame of Heavy-Duty AGVs

Genetic Algorithm-Based Structure Optimization and Load-Carrying Analysis for the Body Frame of Heavy-Duty AGVs

Scheme Exploration and Performance Analysis of 800-Meter Superlarge Span Structure

Superlarge span structure is one of the important trends for future building development. Under the background of the 800-meter superlarge span dome project proposed by China Construction Group, this paper focuses on the structural optimization and performance analysis of this superlarge span structure. The previous ideas of the superdome and the maximum span of existed spatial structures are reviewed, and some structural form selection principles are put forward which lay foundation for structural selection. The applicability of high-strength steel and aluminum alloy is also discussed. It is demonstrated that the high-strength steel and aluminum alloy contribute little to structural comprehensive performances. Then, considering the effects of grid division, members topological relation, and surface shape, six kinds of rigid systems are contrastively studied to determine the optimal scheme. The structural performances along with the increasing span are explored in detail. To further reduce the structural weight and improve mechanical performance, a new composite scheme and the cable-stayed megastructure are proposed and studied. The research methods and performance analysis results can provide significant references for the following research on the superlarge span structure.

Mechanical Structure Design and Optimization Analysis of a new wave Energy Converter

This paper introduces the structural design of a novel wave energy converter, which are mainly divided into energy absorption and energy conversion sections. The upper and lower absorber blades in the energy absorbing section can convert the oscillating wave energy into mechanical energy. The energy conversion section selects a permanent magnet direct-current generator, which can convert the rotating mechanical energy into a direct-current electrical energy output to power a load or a lithium battery. According to the features of large energy and low speed of the wave energy absorbers, the gear ratio of the gear reducer is selected so that the operation of the absorber meets the requirement of the generator working speed.

Application of brazing process design in optimization structure design of scraper

To effectively enhance the service life, the research of milling machine scraper structure design and welding process are optimized. Through the structural optimization analysis, the improved structure is obtained, and the working resistance force is reduced. The full factor test is used to optimize the brazing process, and the best parameters are obtained, which improves the shear strength. The accuracy of the model is verified by experiments. The results show that compared with the working resistance force, the improved scraper tends to be slow and the peak value is smaller. The cutting rake and relief angle of the scraper are optimized. When the cutting rake angle is 6° and the cutting relief angle is 9°, both working resistance force and impact force are minimum. It proves the accuracy of the simulation results. Using CT861 solder, brazing temperature is 75°C, and the brazing time is 10s. While the cooling method uses furnace cold, the minimum value of shear strength is 200MPa. The average working life of the scraper is raised from 800 hours to 1600 hours after the optimization design. Research results have guiding significance for the structure design and the welding process optimization of the scraper.

Synthesis and biological evaluation of coumarin derivatives containing imidazole skeleton as potential antibacterial agents

Emergence of multidrug-resistant bacteria causes an urgent need for new generation of antibiotics, which may have a different mechanism of inhibition or killing action from the existing. Here, we report on the design, synthesis, and biological evaluation of thirty-nine coumarin derivatives in order to solve the antibacterial resistance by targeting at the inhibition of biosynthesis pathway of fatty acids. Their antibacterial activities against Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, and Flavobacterium cloumnare are tested and action mechanism against the key enzyme in bacterial fatty acid synthesis pathway are studied. The results show that compounds 13 and 18 have potent and broad spectrum antimicrobial activity. In addition, 9, 14 and 19 show eminent antimicrobial efficacy toward S. aureus, S. agalactiae, and F. cloumnare. Mechanistically, coumarin derivatives display the antibacterial activity via the control of FabI and FabK function. The structure-activity relationship analysis indicate that the length of linker and imidazole substitute group could significantly influence the antimicrobial activity, as well as the inhibitory activity against FabI and FabK. The structural optimization analysis of coumarin suggest that derivatives 9, 13, 14, 18 and 19 could be a viable way of preventing and controlling bacteria and considered as promising lead compounds for the development of commercial drugs.

DAMAGE CONTROL FUNCTION AND FAILURE PROBABILITY BASED STRUCTURAL SEISMIC PERFORMANCE MULTI-OBJECTIVE OPTIMIZATION AND ASSESSMENT

To avoid global collapse of high-rise building structures caused by the damage of weak stories, a multi-objective optimization method based on damage control function of story group and failure probability was proposed. Through incremental dynamic analysis, the peak acceleration corresponding to the structural failure probability of 50% was selected as the objective earthquake intensity, and two performance indices:the damage control function of story group and failure probability, were defined and the section dimension of components was used as the variables to conduct the structural optimization analysis. A 30-story reinforced concrete frame-core structure was optimized, and the seismic performance of structure before and after optimization was assessed based on PACT (Performance Assessment Calculation Tool). Results indicate that the inter-story drift angle distribution of the optimized structure is more uniform than that of the original structure, and the damage is gradually decreased from the top to the bottom. The Collapse Margin Ratio (CMR) is increased by 29.8, and the repair cost is reduced for both the frame and core tube. The working coordination between the wall and the frame is strengthened, and the seismic perfomance of the structure after optimization has been significantly improved.

Design optimization of rear uprights for UniMAP Automotive Racing Team Formula SAE racing car

In an automobile, the rear upright are used to provide a physical mounting and links the suspension arms to the hub and wheel assembly. In this work, static structural and shape optimization analysis for rear upright for UniMAP’s Formula SAE racing car had been done using ANSYS software with the objective to reduce weight while maintaining the structural strength of the vehicle upright. During the shape optimization process, the component undergoes 25%, 50% and 75 % weight reduction in order to find the best optimal shape of the upright. The final design of the upright is developed considering the weight reduction, structural integrity and the manufacturability. The final design achieved 21 % weight reduction and is able to withstand several loads.

Synthesis and anthelmintic activity of arctigenin derivatives against Dactylogyrus intermedius in goldfish

To control the parasitic disease of Dactylogyrus intermedius, a series of new arctigenin derivatives were designed, synthesized and tested in our study. The anthelmintic activity of most of the derivatives ranged from 1 to 10mg/L. Compared to traditional drug praziquantel (EC50=2.69mg/L), ether derivatives 2g and 2h exhibited slightly higher anti-parasitic activity, with the EC50 values of 2.48 and 1.52mg/L, respectively. Furthermore, the arctigenin-imidazole hybrids 4a and 4b also removed D. intermedius effectively, with the EC50 values of 2.13 and 2.07mg/L, respectively. The structure-activity relationship analysis indicated that four carbon atoms length of linker and imidazole substitute group could significantly increase the anthelmintic activity, and reduced the toxicity. Through the scanning electron microscope observation, compounds 4a and 4b caused the D. intermedius tegumental damage such as intensive wrinkles, holes and nodular structures. Overall, the structural optimization analysis of arctigenin suggested that 4a and 4b can be used for preventing and controlling Dactylogyrus infections and considered as promising lead compounds for the development of commercial drugs.

Discovery of pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivatives as a new class of histone lysine demethylase 4D (KDM4D) inhibitors

Herein we report the discovery of a series of new small molecule inhibitors of histone lysine demethylase 4D (KDM4D). Molecular docking was first performed to screen for new KDM4D inhibitors from various chemical databases. Two hit compounds were retrieved. Further structural optimization and structure-activity relationship (SAR) analysis were carried out to the more selective one, compound 2, which led to the discovery of several new KDM4D inhibitors. Among them, compound 10r is the most potent one with an IC50 value of 0.41±0.03μM against KDM4D. Overall, compound 10r could be taken as a good lead compound for further studies.

Design of a large five-axis ultra-precision ion beam figuring machine: structure optimization and dynamic performance analysis

Large aperture optical components are widely used in deep space exploration and high-precision earth observation system. Ion beam figuring (IBF) is usually used as the last polishing process, and its polishing accuracy determines the optical primary mirror precision, so an IBF machine plays a very important role in the production process of large-size optics. In this paper, the state-of-the-art large-aperture IBF equipment is introduced firstly. Next, the structures, equipment parameters, and design considerations of our IBF equipment are presented. Motion accuracy and dynamic performance are the two prioritized design issues; all researches are carried out around these two issues. Then, the key design points and characteristic analyses of IBF machine are presented, including structure analysis and optimization of the vacuum chamber, the relationship analysis between the dynamic performance of the moving system and the polishing accuracy, and multi-objective optimization design and modal analysis of motion components. Finally, the dynamic characteristics and motion errors of the IBF machine are tested, and the test results show that the machine performance indexes meet the design requirements.

Discovery of New SIRT2 Inhibitors by Utilizing a Consensus Docking/Scoring Strategy and Structure–Activity Relationship Analysis

SIRT2, which is a NAD+ (nicotinamide adenine dinucleotide) dependent deacetylase, has been demonstrated to play an important role in the occurrence and development of a variety of diseases such as cancer, ischemia-reperfusion, and neurodegenerative diseases. Small molecule inhibitors of SIRT2 are thought to be potential interfering agents for relevant diseases. Discovery of SIRT2 inhibitors has attracted much attention recently. In this investigation, we adopted a consensus docking/scoring strategy to screen for novel SIRT2 inhibitors. Structural optimization and structure-activity relationship (SAR) analysis were then carried out on highly potent compounds with new scaffolds, which led to the discovery of 2-((5-benzyl-5H-[1,2,4]triazino[5,6-b]indol-3-yl)thio)-N-(naphthalen-1-yl)acetamide (SR86). This compound showed good activity against SIRT2 with an IC50 value of 1.3 μM. SR86 did not exhibit activity against SIRT1 and SIRT3, implying a good selectivity for SIRT2. In in vitro cellular assays, SR86 displayed very good antiviability activity against breast cancer cell line MCF-7. In Western blot assays, SR86 showed considerable activity in blocking the deacetylation of α-tubulin, which is a typical substrate of SIRT2. Collectively, because of the new scaffold structure and good selectivity of SR86, it could serve as a promising lead compound, hence deserving further studies.

An isogeometrical approach to structural level set topology optimization

This paper aims to utilize the Isogeometric Analysis (IGA) for the level set structural topology optimization. The level set function is parametrized using the Non-Uniform Rational B-Spline (NURBS) basis functions in a higher dimension. The same basis functions are employed for approximating the unknown deformations, geometry modeling of the design domain and the level set function. In this research, three optimization problems including minimization of the mean compliance considering a certain amount of material, minimization of weight with avoiding local stress concentration as well as minimization of weight and strain energy under local stress constraints are dealt with. The sensitivity analyses for the optimization problems are carried out to obtain velocity functions on the boundaries. In order to move the boundaries towards optimum the Hamilton–Jacobi (H–J) equation is solved using the forward Euler scheme. In order to illustrate the performance of the method to obtain reasonable results with smooth boundaries, several numerical examples are presented and compared with well-known problems in literature.

Structure Optimization and Performance Analysis of a Multiple Radial Magnetorheological Valve

Due to the controllable and reversible properties of the smart magnetorheological (MR) fluid, a novel multiple radial MR valve was developed. The fluid flow channels of the proposed MR valve were mainly composed of two annular fluid flow channels, four radial fluid flow channels and three centric pipe fluid flow channels. The working principle of the multiple radial MR valve was introduced in detail, and the structure optimization design was carried out using ANSYS software to obtain the optimal structure parameters. Moreover, the optimized MR valve was compared with pre-optimized MR valve in terms of their magnetic flux density of radial fluid resistance gap and performance of pressure drop. The experimental test rig was set up to investigate the performance of pressure drop of the proposed MR valve under different currents applied and different loading cases. The results show that the pressure drop between the inlet and outlet port could reach 5.77 MPa at the applied current of 0.8 A. Furthermore, the experimental results also indicate that the loading cases had no effect on the performance of pressure drop.

Structural Optimization Analysis on a New Type of Cable-Girder Anchorage Structure

Structural Optimization Analysis on a New Type of Cable-Girder Anchorage Structure

Hybrid of topological derivative-based level set method and isogeometric analysis for structural topology optimization

This paper proposes a hybrid of topological derivative-based level set method (LSM) and isogeometric analysis (IGA) for structural topology optimization. In topology optimization a significant drawback of the conventional LSM is that it cannot create new holes in the design domain. In this study, the topological derivative approach is used to create new holes in appropriate places of the design domain, and alleviate the strong dependency of the optimal topology on the initial design. Furthermore, the values of the gradient vector in Hamilton-Jacobi equation in the conventional LSM are replaced with a Delta function. In the topology optimization procedure IGA based on Non-Uniform Rational B-Spline (NURBS) functions is utilized to overcome the drawbacks in the conventional finite element method (FEM) based topology optimization approaches. Several numerical examples are provided to confirm the computational efficiency and robustness of the proposed method in comparison with derivative-based LSM and FEM.