Optimal Structural Parameters Research Articles

Designing Load-Bearing Bio-Inspired Materials for Simultaneous Static Properties and Dynamic Damping: Multi-Objective Optimization for Micro-Structure

Biological load-bearing materials, like the nacre in shells, have a unique staggered structure that supports their superior mechanical properties. Engineers have been encouraged to imitate it to create load-bearing bio-inspired materials which have excellent properties not present in conventional composites. To create such materials with desirable mechanical properties, the optimum structural parameters combination must be selected. Moreover, the optimal design of bio-inspired composites needs to take into account the trade-offs between various mechanical properties. In this paper, multi-objective optimization models were developed using structural parameters as design variables and mechanical properties as optimization objectives, including stiffness, strength, toughness, and dynamic damping. Using the NSGA-II optimization algorithm, a set of optimal solutions were solved. Additionally, three different structures in natural nacre were introduced in order to utilize the better structure when design bio-inspired materials. The range of optimal solutions that obtained using results from previous research were examined and explained why this collection of optimal solution ranges is better. Also, optimal solutions were compared with the structural features and mechanical properties of real nacre and artificial biomimetic composites to validate our models. Finally, the optimum design strategies can be obtained for nacre-like composites. Our research methodically proposes an optimization method for achieving load-bearing bio-inspired materials with excellent properties and creates a set of optimal solutions from which designers can select the one that best suits their preferences, allowing the fabricated materials to demonstrate preferred performance.

Numerical Design and Optimization of High Performance Langasite and Hetero-Acoustic Layer-Based Surface Acoustic Wave Device

La3Ga5SiO14 (langasite, LGS)-based surface acoustic wave (SAW) devices are widely used for industrial health monitoring in harsh high-temperature environments. However, a conventional LGS-based SAW structure has a low quality factor (Q) due to its spurious resonant peaks. A hetero-acoustic layer (HAL)-based structure can effectively enhance the Q factor and the figure of merit (FOM) of SAWs due to its better energy confinement of SAWs. In this work, a HAL-based structure is proposed to achieve a high FOM and high-temperature resistance at the same time. Based on the finite element method (FEM) and coupling-of-model (COM) combined simulation, a systematic numerical investigation was conducted to find the optimal materials and structural parameters considering the viability of an actual fabricating process. After optimizing the layer number, an intermediate-layer material choice and structural parameters, Pt/(0°, 138.5°, 27°) LGS/YX-LGS/SiC HAL structure were chosen. The proposed structure achieves a Q factor and FOM improvement of more than 5 and 2.6 times higher than those of conventional SAW structures, which is important for the development of high temperature SAW sensors. These findings pave a viable method for improving the Q factor and FOM of LGS-based SAW and can provide material and device structural design guidance for fabrication and high-temperature applications in the future.

Ultrafast pulse propagation time-domain dynamics in dispersive one-dimensional photonic waveguides

Abstract Ultrafast pulses, particularly those with durations under 100 fs, are crucial in achieving unprecedented precision and control in light–matter interactions. However, conventional on-chip photonic platforms are not inherently designed for ultrafast time-domain operations, posing a significant challenge in achieving essential parameters such as high peak power and high temporal resolution. This challenge is particularly pronounced when propagating through integrated waveguides with nonlinear and high-dispersion profiles. In addressing this challenge, we present a design methodology for ultrafast pulse propagation in dispersive integrated waveguides, specifically focused on enhancing the time-domain characteristics of one-dimensional grating waveguides (1DGWs). The proposed methodology aims to determine the optimal structural parameters for achieving maximum peak power, enhanced temporal resolution, and extended pulse storage duration during ultrafast pulse propagation. To validate this approach, we design and fabricate two specialized 1DGWs on a silicon-on-insulator (SOI) platform. A digital finite impulse response (FIR) model, trained with both transmission and phase measurement data, is employed to obtain ultrafast time-domain characteristics, enabling easy extraction of these results. Our approach achieves a 2.8-fold increase in peak power and reduces pulse broadening by 24 %, resulting in a smaller sacrifice in temporal resolution. These results can possibly pave the way for advanced light–matter interactions within dispersive integrated waveguides.

Optimized PCF architectures for THz detection of aquatic pathogens: Enhancing water quality monitoring.

Waterborne bacteria pose a serious hazard to human health, hence a precise detection method is required to identify them. A photonic crystal fiber sensor that takes into account the dangers of aquatic bacteria has been suggested, and its optical characteristics in the THz range have been quantitatively assessed. The PCF sensor was designed and examined as computed in Comsol Multiphysics, a program in which uses the method of "Finite Element Method" (FEM). At 3.2 THz operating frequency, the proposed sensor performs better than the others in all tested cases, with a high sensitivity of 96.78% for Vibrio cholera, 97.54% for E. coli, and 97.40% for Bacillus anthracis. It also has a very low CL of 2.095 × 10-13 dB/cm for Vibrio cholera, 4.411 × 10-11 dB/cm for E. coli, and 1.355 × 10-11 dB/cm for Bacillus anthracis. The existing architecture has the potential to produce the sensor efficiently and scalable, opening the door for commercial applications. The innovation is in the optimization of structural parameters to increase the fiber's sensitivity to bacterial presence, thereby improving the interaction between terahertz waves and bacterial cells. It targets bacterial macromolecule absorption peaks to increase sensitivity. Localized field augmentation, which concentrates THz vibrations where bacteria interact more, may arise from optimization. By improving scattering, structural alterations can help identify bacteria by their characteristic scattering patterns. These improvements improve the sensor's trace bacteria detection. These factors increase the sensor's aquatic germ detection when combined. In aqueous environments, this results in a more precise and efficient detection, which could facilitate the real-time monitoring of bacterial contamination. Public health and water quality control may be significantly affected by these developments.

High-Order Grid-Connected Filter Design Based on Reinforcement Learning

In grid-connected inverter systems, grid-connected filters can effectively eliminate harmonics. High-order filters perform better than conventional filters in eliminating harmonics and can reduce costs. For high-order filters, the use of multi-objective optimization algorithms for parameter optimization presupposes that the circuit structure must be known. To realize the design of the filter structure and related circuit parameters that meet the requirements of the grid-connected inverter system during the design process, this paper proposes a reinforcement learning (RL) method for designing higher-order filters. Our approach combines key domain knowledge with the characteristics of structural changes to obtain some constraints, which are then processed to obtain reward and are incorporated into RL strategy learning to determine the optimal structure and corresponding circuit parameters. The proposed method realizes the simultaneous design of parameters and structures in filter design, which greatly improves the efficiency of filter design. Simulation results for the corresponding grid-connected system setup show that the grid-connected filter designed by our method demonstrates a good performance in terms of filter dimension, harmonic rejection, and total harmonic distortion.

Optimum Design and Dynamics Analysis of Intelligent Prosthetic Knee Joint

Background: The intelligent prosthetic knee joint is an essential rehabilitation device for amputee patients to recover from mobility disorders. It must ensure excellent performance when installed on the human body. However, issues such as excessive energy consumption and poor stability during walking are challenges in the design of such prosthetic devices. Objective: To address the issues of wasteful energy expenditure and instability in intelligent prosthetic knee joints during walking, an optimized model of a double rocker prosthetic knee joint mechanism was established with the minimum peak driving torque of the active rod as the optimization goal. Methods: The optimal model was established with the minimum peak driving moment of the prosthetic knee joint mechanism as the optimization objective. Under the constraint conditions of performance and structure, the model was optimized by the composite method, and the optimal structural parameters of the prosthetic knee joint mechanism were obtained. Then, according to the trajectory of the instantaneous rotation center of the knee joint, the double rocker mechanism is optimized so that the prosthesis can better simulate the movement trajectory of normal people. Finally, according to the designed virtual prototype model, a physical prototype of the intelligent prosthetic knee joint test platform is built, the knee joint Angle data is collected, and the collected data is analyzed accordingly. Results: ADAMS software was used to simulate the virtual motion of the optimized model. The results showed that the optimized intelligent prosthetic knee joint mechanism has excellent bionic performance. Its peak driving torque is reduced by 40% and the range of driving torque is reduced by 36%, significantly improving the stability and endurance of the intelligent prosthetic knee joint. Through the experimental test of an intelligent prosthetic knee joint, it is verified that the optimized intelligent prosthetic knee joint meets the normal needs of the human body. Conclusion: The results confirm that the optimized prosthetic knee joint mechanism exhibits excellent bionic performance, and the reduction in driving torque enhances its stability and energy efficiency, validating the correctness and rationality of the proposed optimization model.

Hydrogel‐Based Photothermal‐Catalytic Membrane for Efficient Cogeneration of Freshwater and Hydrogen in Membrane Distillation System

AbstractPhotothermal‐catalytic (PTC) process is a promising way to produce freshwater and clean hydrogen by integrating solar‐driven desalination and water splitting. However, efficient solar spectrum utilization coupled with effective mass and thermal management poses key challenges in developing multifunctional PTC systems. Here, a highly stable hydrogel membrane (CdS/MX‐HM) that incorporates MXene and in‐situ generated CdS as the PTC materials into a customized vacuum membrane distillation (VMD) setup is demonstrated. The CdS/MXene composites utilize the full solar spectrum, with MXene contributing to photothermal ability and serving as a co‐catalyst to enhance photocatalytic performance, which are effectively integrated into the membrane system. These functional materials are immobilized within the hydrophilic PVA/chitosan hydrogel layer, which creates a supramolecular network that provides excellent stability and protection while offering an interface for PTC processes. Supported by the hydrophobic PTFE membrane substrate, the integrated system enables fast gas transfer to the permeate, completing the dual‐function design. Through systematic optimization of membrane structure and operational parameters, the PTC‐VMD system achieves a water flux of 1.63 kg m−2 h−¹ and a hydrogen production rate of 3099 µmol m−2 h−1 under one sun irradiation, demonstrating its potential as a sustainable solution for the water‐energy nexus challenge.

Structural parameter optimization of a fused all-fiber probe for light manipulation and multi-particle capture

We propose and experimentally demonstrate an economical optical tweezers probe based on the fusion of several commercial optical fibers. By optimizing the structural parameters of the probe, non-contact active capture and manipulation of single or multiple biological particles were achieved. First, the probe structural parameter range was analyzed theoretically, and the theory was cross-verified by the finite element method. Second, the influence of the probe structure and length parameters on the laser focusing performance and particle capture ability was studied, and the optimal structural parameters of the probe in particle capture were determined. The measured capture distance exceeded 50 µm, and the movement velocity of the particle during manipulation was measured. Finally, the capture performance before and after parameter optimization was compared with the dynamic effect of the particles, and the generation mechanism of multiple light traps and the mechanical properties of multi-particles during multi-particle capture were studied. The results indicate that this probe is expected to be used in biological or chemical micromanipulation research.

Structural topology and parameter optimization of torsional dampers used in parallel hybrid electric vehicles based on the working conditions

Hybrid electric vehicles (HEVs) are equipped with multiple power sources and involve complex mode-switching processes, which lead to intricate torsional vibration characteristics in their powertrains. This paper presents a novel clutch torsional damper with arc springs (CTD-AS) that combines the advantages of traditional clutch torsional dampers (CTDs) and dual-mass flywheels (DMFs). The structure and working principle of the CTD-AS are introduced in the paper, and a torsional damper parameter design method is discussed. During the study, a 13-degree-of-freedom concentrated mass model was established for an HEV powertrain, and optimization schemes based on multiple sets of operating conditions were obtained for a CTD, a DMF, and the CTD-AS. The optimized simulation results demonstrated that the average torsional vibration transmissibility value of the CTD-AS under the three working conditions was approximately 13.8% and 29.7% lower than that of the DMF and the CTD, respectively, and the overall performance is the best. The novel structural topology and parameter optimization method for the torsional damper of a parallel HEV proposed in this paper can effectively enhance driving smoothness under a variety of working conditions.

Research on the optimization of drum structure based on virtual prototyping technology

Drums are the core working mechanism of the coal mining machine for coal mining. The structural design level of the drum is crucial for mining efficiency and safety production. Traditional design methods not only have long design cycles and high costs, but also limited design capabilities. This study used computer numerical simulation methods to establish coupled models for drum cutting complex coal seams, which was used to obtain the working performance of drums with different structures. By fitting the comprehensive performance evaluation function of the drum, the optimal structural parameters are obtained through the improved Non-Dominated Sorting Genetic Algorithms (NSGA-II). Taking into account both technical and economic factors, the optimal helix angle is ultimately determined to be 18°, the optimal installation angle is 45°, and the optimal cutting distance is 71 mm. Through experiments, it has been proven that the performance of the optimized drum has significantly improved. Specifically, the average cutting resistance has been reduced by 12.72%, the load fluctuation coefficient has been reduced by 9.81%, the cutting specific energy consumption has been reduced by 2.85%, and the coal loading rate has been increased by 9.59%, providing a reference for the optimization design of the shearer drum structure.

Solar radiation model and optimization of asymmetric large-span externally insulated plastic greenhouses.

To improve the light environment of asymmetric large-span externally insulated plastic greenhouses, a solar radiation model that considers the projection path equations of the insulation quilts and validated the model was established. The model was employed to investigate the impact of different heights, spans, and north lighting projection lengths on the greenhouses' light environment. The results revealed that ground radiation interception, a key component of winter lighting, was most influenced by height, followed by span, and least influenced by the projection length of the north lighting roof. Additionally, ground radiation spatial uniformity was most affected by height, followed by the projection length of the north lighting roof, and least influenced by span. The optimization objectives for solar radiation were set to maximize solar radiation interception and minimize the coefficient of variation. The optimal structural parameters for the asymmetric large-span externally insulated plastic greenhouse were determined using the NSGA-II method and the entropy weight-TOPSIS method: the height of 6.97 m, and the projection length of north lighting roof is 7.44 m for a greenhouse with a span of 20.00 m. Compared to the initial greenhouse, the optimized design enhances both radiation interception performance and ensures uniform light distribution. These results offer valuable theoretical guidance for greenhouse construction.

Research Progress in Pre-Stage Deflection Jet Tube Type Electro-Hydraulic Servo Valve

Background: The pre-stage deflection is a key aspect of the deflector jet tube electrohydraulic servo valve, and its performance not only affects the pressure gain, flow gain, and other important parameters of the servo valve, but also affects the dynamic and static characteristics of the servo valve and electro-hydraulic servo system. Objective: This paper aimed to outline the working principle of the pre-stage deflector jet tube type electro-hydraulic servo valve, and review and analyze its research performance development in five aspects. Method: The research progress in the key indexes of servo valve performance at different stages, the mechanism and phenomenon of the erosion and wear of the pre-stage, the mechanism and characteristics of the pre-stage cavitation, the structural improvement and parameter optimization of the pre-stage, as well as the pre-stage drive mode, has been summarized. Results: It has been found that although a large number of scholars at home and abroad have improved the structure and driving mode of the front stage of the deflecting jet tubular electrohydraulic servo valve and optimized the parameters to improve the performance of the deflecting jet tubular electro-hydraulic servo valve, the internal flow field of the front stage is complex, prone to erosion and cavitation and many complex phenomena, and there are still many aspects to be improved and innovated. Conclusion: This paper has thus summarized the defects of the front-end stage, and put forward three future innovations of miniaturization, intelligence, and multifunction, to contribute innovative ideas to the design of the front-end stage of the deflection jet pipe electro-hydraulic servo valve in the future.

Crashworthiness analysis of a novel corrugated multi-cellular tube structure

This study innovatively combines Fourier curves with circular tube design and proposes a novel corrugated multi-cellular tube structure (NCMTS), aiming to improve crashworthiness. The accuracy of the finite element model was validated through axial quasi-static compression tests. The influence mechanism of different structural parameter combinations on the energy absorption capacity of NCMTS was further investigated. The results reveal that the EA of NCMTS increases monotonically with rising of parameter ru , with a notable acceleration in growth rate as parameter Rc is elevated. Notably, the combination of larger values of ru and Rc , and tout and tc can significantly improve the crashworthiness performance. Moreover, appropriately increasing C 1 and C can increase the EA of NCMTS by approximately 50%. Through multi-objective optimization analysis utilizing the global response surface method, the optimal structural parameters for NCMTS were identified: at Rc = 0.68, C = −0.57, C 1 = 0.16, tout = 2.0 mm, tc = 0.68, the EA, SEA and IPCF reached 7.02 kJ, 15.33 kJ/kg and 400 kN respectively. This study offers valuable guidance for the design and optimization of high-performance collision energy-absorbing structures.

Optimization of manifold structural parameters for high-power proton exchange membrane fuel cell stack

Optimization of manifold structural parameters for high-power proton exchange membrane fuel cell stack

EDEM-based study on the adjustable feeding parameters of square bale maize straw bale-breaking device.

One of the primary challenges faced by small rubbing filament machines is the significant variability in material sizes, particularly in the feeding direction. This variability complicates the processing of locally baled straw with a single device. To address this issue, an adjustable feeding and bale-breaking device was developed and tested to enhance the filamentous performance of baled straw. The machine integrates a series of bale-breaking knives along with a pair of feeding and bale-breaking rollers. This paper presents an overview of the machine's structure and operating principles, alongside an analysis of the forces acting on the straw within the device, which informed the design of key components and devices. A discrete element simulation model suitable for square baled-straw has been established, providing a research foundation for the subsequent optimization of device design parameters. Effects of motor bale-breaking roller rotating speed (x1), bale-breaking roller height (x2) and bale-breaking knife quantity (x3) on the productivity of bonding bond destruction rate (Y1) and the particle average speed (Y2) were explored. Three-dimensional quadratic regression orthogonal rotation central combination experiment method combined with response surface method was used to conduct experiments and explore the interaction effects of influence factors on indicators. A regression model of influence factors and evaluation indicators was established through the analysis of variance. The significant factors affecting Y1 were ordered of x1, x2, x3, and the significant factors affecting Y2 were ordered of x2, x3, x1. In the interaction of factors, x1x2 and x2x3 had an extremely significant impact, and x1x3 had a significant impact on Y1; x1x2, x1x3 and x2x3 had a significant impact on Y2. The optimal structure and working parameters combination were determined to be 1448 rpm for x1, 268 mm for x2, and 14 pieces for x3. Verification experiments demonstrated that the actual values were 96.95% for the straw rubbing rate and 235.13 kg/(kW·h) for the per unit power productivity. The operation of the adjustable feeding and bale-breaking device developed in this study proved effective in enhancing productivity and breaking performance during the feeding of baled straw. It successfully met the design requirements for the grain size necessary for the comprehensive utilization of straw. Overall, this research establishes a foundational basis for the further development of a small, multipurpose straw rubbing filament machine.

DESIGN AND TEST OF A SUPPORT CUTTING ANTI-CLOGGING DEVICE WITH VIBRATION FOR A NO-TILL SEEDER

ABSTRACT The anti-clogging device of a no-till seeder is an important component that affects the seeding quality. In one year two crop area of China, a no-tillage seeder for corn generally includes a passive anti-clogging device, and there are often problems with straw winding around working parts due to the low straw cleaning rate. To solve these problems, a support cutting anti-clogging device with vibration for a no-till seeder was designed in this study to efficiently cut wheat stalks and remove them to the sides of the seedbed. Through theoretical calculations and kinematic analysis, the main structural parameters of the device were limited to small ranges of values: the mounting angle of the vibrating knife was in the range θ1 = 70–82°, the amplification was in the range l1 = 14–24 mm, and the frequency was in the range ωm = 240–340 rad/min. To analyse the effects of the main parameters on the average straw cutting rate, soil bin experiments were carried out using an orthogonal multinomial regressive experimental design with three factors and three levels. The optimal structural parameters derived in this way were as follows: mounting angle for the vibrating knife θ1 = 70.7°, amplification l1 = 19 mm, and frequency ωm = 330.2 rad/min. The results of adaptability and comparison tests showed that the average straw cutting rate was 93.30% when the proposed anti-clogging device with vibration was used. Compared to traditional devices, the cutting rate for the device was increased by 12.82%, and the metrics were superior to those of a traditional anti-clogging device. This research can serve as a reference for designing anti-clogging devices for no-till seeders.

A novel design and structural parameters optimization of electrostatic coupled fringing electric field sensor

A novel design and structural parameters optimization of electrostatic coupled fringing electric field sensor

A generic framework for ETW-based dimensional synthesis of parallel mechanism

In this paper, a general dimensional synthesis framework for parallel mechanisms is established based on the effective transmission workspace (ETW) model. Firstly, differential variational operators are added to the population updating strategy of Teaching-learning-based optimization (TLBO) algorithm to accelerate the population updating speed, and named as Accelerated teaching-learning-based optimization (ATLBO) algorithm. Then, typical function examples and mechanical optimization design examples are used to prove that ATLBO algorithm has obvious performance improvement compared with TLBO algorithm. Finally, based on the screw theory, the dimensional synthesis model for ETW maximization is proposed, and ATLBO is applied to solve the optimal structural parameters. Comparison of the calculated ETW indexes before and after the optimization shows that the dimensional synthesis model of this paper for parallel mechanism is workable and effective. This work provides a modeling solution for the dimensional synthesis problem of space mechanism.

The Structural Design and Analysis of the Multi Nozzle Relay Air-Jet Inserting System by Profile Reed Guiding for 3D Weaving Machine

Introduction: Based on the literature, this article designs a parameterized simulation model of a multi-layer jet weft insertion system by profiles reed guidance for a 3D loom on the PTC Creo9.0 platform, including the main supersonic nozzle, supersonic auxiliary nozzle (relay nozzle), and multi-slot profiles reed components. Method: Based on the existing basic theory, experimental results, and empirical data of turbulent jet, the parameters of the multi-layer jet weft insertion system, as well as the structural parameters and the relative positions of the main, auxiliary nozzle and profile reed components, such as the center distance of each layer's main nozzle, auxiliary nozzle spacing, auxiliary nozzle installation angle, spray direction angle, and spray angle, have been determined preliminarily. Result: Further, the basic flow field parameters, such as the supply pressure of the main and auxiliary nozzles and the shape of multi-layer profile reeds, have been determined optimally on the Virtual Prototype Collaborative Simulation Platform (PTC Creo9.0/ANSYS Workbench/Fluent 2024R1), and the rationality of the structural design also been verified; on the premise of ensuring that the airflow velocity of each layer's profiles groove meets the requirements of weft insertion, the design and simulation calculation is repeatedly modified, and the optimal structural design parameters of the multi-layer weft insertion system and nozzle is finally determined. Conclusion: To explore the feasibility of multi-layer jet weft insertion, the design of threedimensional multi-layer jet weft insertion looms has laid a theoretical foundation, laying a good foundation for the emergence and industrial manufacturing of three-dimensional multi-layer jet weft insertion looms, and providing an important reference for the innovative design of threedimensional multi-layer water jet weft insertion looms.

Optimization of Stope Structural Parameters for Steeply Dipping Thick Ore Bodies: Based on the Simulated Annealing Algorithm

Optimization of Stope Structural Parameters for Steeply Dipping Thick Ore Bodies: Based on the Simulated Annealing Algorithm