Selection Of Design Parameters Research Articles

I/O system of V-band second harmonic gyrotron for 100/200 kW operation

This paper presents the design studies of the common input and output system of a continuous wave (CW), V-band gyrotron at second harmonic for plasma diagnostics application. Two different designs are carried out with design 1 operating at TE7,3 mode having same geometrical parameters for dual power operation of 100 kW and 200 kW and design 2 operating at TE8,3 mode has same geometry that can support dual power operation of 100 kW and 200 kW respectively. The selection of the initial design parameters has been done using our in-house computer code Gyrotron Design Studio Second Harmonic Version 2020 (GDS2H-2020). The electron guns along with magnetic guidance systems are designed to generate electron beam with the required beam parameters using software package EGUN. The design and optimization of the Non-Linear Taper (NLT), Quasi-Optical Launcher (QOL) and RF window are carried out for both the designs. NLTs are optimized for maximum transmission efficiency of the desired modes using Computer Simulation tool (CST). QOLs are designed for converting the operating modes into Gaussian-like mode using commercial software packages Launcher Optimization Tool (LOT) and SURF3D. The designs of the single-disk RF window for high-power output beam extraction are performed using CST.

Innovative non-asymptotic and robust estimation method using auxiliary modulating dynamical systems

In this paper, we aim to introduce an innovative non-asymptotic and robust estimation method based on the observable canonical form by means of a set of auxiliary modulating dynamical systems. The latter auxiliary systems are given by the controllable canonical form with zero initial condition. The proposed method can be applied to many kinds of linear and nonlinear systems. In this paper, it is applied to estimate the states and the output’s derivatives for linear singular systems with multiple inputs and multiple outputs in noisy environment. First, the considered singular system is transformed into a form similar to the Brunovsky’s observable canonical form with the injection of the inputs’ and outputs’ derivatives. Second, algebraic integral formulas are obtained both for the state variables and the outputs’ derivatives. After giving solutions of the required auxiliary systems, error analysis in discrete noisy case is addressed, where a provided noise error bound can be used to select design parameters. In the end, numerical simulations are given to illustrate the performance of the proposed method.

Selection of design parameters of straddle monorail system considering vehicle–bridge interaction

Vehicle–bridge interaction (VBI) is an essential focal point in the design of straddle monorail systems. Existing studies on them primarily use multibody dynamics software, however, it is disadvantageous as several important factors such as nonlinear excitations, structural nonlinearity, and bridge alignment defects cannot be analyzed. Therefore, a co-simulation approach is proposed in this paper to investigate the dynamic responses of the straddle monorail VBI system where various factors can be easily considered. The proposed approach couples bridge and vehicle subsystems through global iterations with the exchange of wheel-rail contact forces and bridge responses calculated using MATLAB and ANSYS, respectively. The accuracy of the proposed approach is validated using numerical and experimental data reported in existing literature. Further, the effect of design parameters on the dynamic responses of the straddle monorail VBI system is analyzed using the proposed approach. The analysis results indicate that a single-axle straddle monorail train outperforms the conventional two-axle train with reduced dynamic responses and lighter mass. Recommendations are provided for the stiffness and damping of the guiding, stabilizing, and riding wheelsets, as well as for the vertical and lateral stiffness and damping of the air springs. The radius of a girder curve should be at least 150 m over regular operation sections to ensure riding safety; it can be less at special entrance and exit sections where the train speed is low. The findings of these parametric analyses provide guidelines to select proper design parameters for straddle monorail systems to mitigate dynamic responses.

Combined Thermal and Wear Analysis of Linear Rolling Guide Subjected to Rigid–Flexible Coupling Motion Stage

The local heat and wear generated due to friction in a precision motion stage in electronic packaging equipment have a significant impact on its positioning precision. In this paper, we studied the temperature changes over time and the wear of a linear rolling guide (LRG) in a rigid–flexible coupling motion stage (RFCMS), both analytically and experimentally, and we proposed an evaluation method for LRG wear in an RFCMS. According to Fourier’s law and the law of conservation of energy, the differential equation of heat conduction for the LRG and the thermal boundary conditions were established. Steady-state and transient thermal simulations were carried out using ANSYS Workbench to predict the temperature increase in the LRG due to friction. Finally, a test apparatus was built to demonstrate that an RFCMS reduced the operating temperature of the LRG, which also reduced the wear on the contact surface. Through response surface methodology, the levels of the influence of different flexure hinge thicknesses, strokes, velocities, and accelerations on the temperature change rate (TCR) of the LRG were obtained, as well as the approximate regression equation of four variables of the TCR. This provided a new research method for precision maintenance, life design, and operational parameter selection for high-precision motion stages.

Seismic resilient design of rocking tall bridge piers using inerter-based systems

Seismic resilient design of tall bridge piers with rocking foundation by using inerter-based systems is investigated in this work. A simplified model is developed in OpenSees to simulate the rocking bridge pier equipped with a tuned viscous mass damper (TVMD) system, wherein nonlinearity of the pier response is incorporated through a distributed-plasticity fiber-based section approach; the rocking behavior is simulated through elastic-no-tension spring elements located at the foundation interface of the pier as per FEMA 356 recommendations; an equivalent model comprising a rotational mass linked with the two terminals of the TVMD through appropriate constraint conditions is utilized for modeling the inerter-based system. Optimal design parameters of the TVMD are determined through an extensive parametric analysis, aiming to minimize the tilt angle of the bridge pier. The effectiveness of the selected design parameters of the TVMD on the seismic mitigation performance of rocking tall piers is then investigated numerically. Besides, guidelines are proposed for the design of TVMD parameters in engineering practice based on these analytical results. Nonlinear time-history analysis is conducted under both far-field and near-fault motions, followed by seismic fragility analysis for the overturning damage state, assuming the peak ground acceleration as intensity measure and the dimensionless tilt angle as the engineering demand parameter. The parametric analysis results show that the TVMD is less efficient for near-fault motions, due to reduced energy dissipation capacity caused by pulse-type feature. Additionally, the optimal parameters obtained from parametric analysis could be generalized to a higher number of seismic excitations, achieving a similar seismic performance, which indicates robustness of the TVMD. The TVMD is found able to reduce the tilt angle at the rocking interface especially during strong earthquake events, consequently increasing the overturning stability of rocking foundations adopted for tall bridge piers.

Multi-objective crashworthiness optimization of square aluminum tubes with functionally graded BCC lattice structure filler

The objective of this study is to find the optimum design configurations for the crashworthiness of functionally graded lattice structure filled aluminum tubes under multiple impact loading conditions. Base strut diameter, draft angle and aspect ratio are considered as filler material design parameters, and the optimal design configurations are sought for maximizing the specific energy absorption and minimizing the peak crush force. The finite element simulations are performed to establish the sample design space; linear and non-linear least square regression meta-models are developed to estimate the objective function values; the weighted superposition attraction-repulsion algorithm is employed to create design alternatives and seek their optimum combinations. The compromise programming technique is also adapted for combining multiple objectives and generating different optimum design options. The results revealed that the proper selection of design parameters can effectively enhance the crashworthiness performance of hybrid structures under multiple impact loading conditions. In particular, the results showed that the specific energy absorption value of square tubes can be improved up to 76% with the selection of appropriate lattice filler parameters. The present study provides a guideline for the optimum design of functionally graded lattice structure filled thin-walled structures under multiple impact loading conditions.

Bifurcation Control for a Ship Maneuvering Model with Nonsmooth Nonlinearities

We consider a widely used form of models for ship maneuvering, whose nonlinearities entail continuous but nonsmooth second-order modulus terms. For such models bifurcations of straight motion are not amenable to standard center manifold reduction and normal forms. Based on a recently developed analytical approach, we nevertheless determine the character of local bifurcations when stabilizing the straight motion course with standard proportional control. For a specific model class we perform a detailed analysis of the linearization to determine the location of these bifurcations in the control parameter space and its dependence on selected design parameters. By computing the analytically derived characteristic parameters, we find that “safe” supercritical Andronov–Hopf bifurcations are typical. Through numerical continuation we provide a more global bifurcation analysis, which identifies the arrangement and relative location of stable and unstable equilibria and periodic orbits.

Design method of asphalt mixture with balanced noise reduction and mechanical properties

A design method of asphalt mixture is proposed for reducing the tyre/road noise while having good mechanical properties. Firstly, by comparing the simulated sound absorption coefficient curve with noise-frequency curve from practical road surface, the target air voids contents are obtained. Then, models which can predict the texture level and sound absorption coefficient from the given mixture properties, such as porosity, gradation, particle size, asphalt content, etc. as inputs parameters, are used for preliminarily selecting the design parameters of mixture. Test samples are made according to these selected design parameters in the lab. Test vales of the texture level, sound absorption coefficient and the skid resistance of the mixtures are obtained from laboratory measurements. These measurement values are used for predicting the attenuation of the tyre/road levels by means of statistical models. Mixtures with superior predicted noise reduction properties are selected for mechanical performance validation. Mixture design which shows the promising noise reduction properties as well as satisfying the mechanical performance requirement are considered as the optimal one, and it is suggested to be used as the road surface. Road surface designed from this method can both meet the needs of traffic load and noise reduction function.

Material Properties and Electric–Thermal–Stress Multiple Fields Coupling Simulation of Power Distribution Cable Accessories

In engineering applications, the material properties of the cable accessories are affected by electrical, thermal, and mechanical stress. In this work, the comprehensive properties of the insulation material and the semi-conductive material for the cable accessory are studied. Furthermore, the multiphysics field coupling simulation model is established to study the distribution and variation in electric, thermal, and stress fields. The experimental results show that the relative permittivity of silicone rubber (SiR) and cross-linked polyethylene (XLPE) gradually decreases with the increasing temperature, with values of 2.29 and 3.39 at room temperature, respectively. The thermal conductivity of the semi-conductive material is higher than that of SiR and XLPE, with values of 0.39, 0.21, and 0.30 W/( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\cdot \text{K}$ </tex-math></inline-formula> ) at room temperature. In contrast, the semi-conductive material has a relatively low thermal expansion coefficient. The elasticity modulus of XLPE at room temperature is approximately 97.62 MPa. Moreover, the mechanical properties of the three materials are relatively good. The simulation results show that the electric field distortion caused by the temperature change is slight. The maximum electric field distortion point locates at the stress cone root, with a value of 2.22 kV/mm. The highest temperature of the cable accessory is approximately 50.31 °C, and the temperature difference between the inside and outside reaches 5.84 °C, which will cause a significant interface stress change. Besides, the internal temperature and temperature difference in the cable accessory vary widely with ambient temperatures and current loadings. The research will be guiding significance for material selection, structural design, and interfacial stress parameter selection of the cable accessories.

Globally Adaptive Neural Network Tracking for Uncertain Output-Feedback Systems.

This article investigates the problem of global neural network (NN) tracking control for uncertain nonlinear systems in output feedback form under disturbances with unknown bounds. Compared with the existing NN control method, the differences of the proposed scheme are as follows. The designed actual controller consists of an NN controller working in the approximate domain and a robust controller working outside the approximate domain, in addition, a new smooth switching function is designed to achieve the smooth switching between the two controllers, in order to ensure the globally uniformly ultimately bounded of all closed-loop signals. The Lyapunov analysis method is used to strictly prove the global stability under the combined action of unmeasured states and system uncertainties, and the output tracking error is guaranteed to converge to an arbitrarily small neighborhood through a reasonable selection of design parameters. A numerical example and a practical example were put forward to verify the effectiveness of the control strategy.

Complibot: A compliant external pipe climbing robot

The article presents the design of Complibot, a robot with a novel gripper for pipe climbing. The mechanism of the gripper involves the use of a bistable buckled beam, which is a type of bistable compliant mechanism. The bistable buckled beam in the gripper is alternately actuated between its gripped and ungripped states using a camshaft and lever mechanism, which is powered by a single DC motor. The design parameters associated with the gripper are obtained both experimentally and numerically. A proper selection of design parameters helps in the efficient functioning of the gripper. After the design of the gripper, two such grippers are fabricated and attached to each other by two stepper motor-driven lead screws to make a pipe climbing robot with inchworm locomotion. The mobility of the robot is controlled by an Arduino Uno microcontroller after the electronic components have been integrated. Finally, Complibot is subjected to a series of tests to establish its maximum load-carrying capacity when climbing a polyvinyl chloride (PVC) pipe. Complibot is found to perform satisfactorily without slipping while climbing a PVC pipe with a diameter of 105–115 mm, a velocity of 0.2 m/min, a power consumption of 18.58 W, a maximum load-carrying capacity of 114.64 N, and a payload to weight ratio of 0.52.

Thermal regulation mechanism of air-drying shelter to indoor environment of earth buildings located in Turpan basin with extremely dry and hot climate conditions

This study investigates the thermal regulation mechanism of air-drying shelter of earth buildings located in Turpan basin to indoor thermal environment under the extremely dry and hot climate condition. Firstly, a field measurement lasting for three days was performed to investigate the thermal effect of air-drying shelter on indoor thermal condition. The measured results indicated that air-drying shelter provides the shaded space and natural ventilation to reduce the internal surface temperature of the roof and further improve the indoor thermal comfort in the hot summer. Then, a series of numerical studies on the effects of design parameters of air-drying shelter on indoor environment of earth building in Turpan basin were performed. The selected design parameters of air-drying shelter included air-drying shelter to room height ratio, thickness of carved walls, thickness of air-drying shelter's roof and hole to wall area ratio. The simulated results demonstrated that hole to wall area ratio of the carved walls is considered as an important design parameter of air-drying shelter, and increasing hole to wall area ratio of carved walls could increase solar radiation heat gain of roof, leading to increasing internal surface temperature of roof and indoor air temperature.

Application of mechanical product design parameter optimization based on machine learning in identification

The selection of mechanical product design parameters is a key factor in determining product quality. The defects caused by unreasonable product parameter design are one of the main reasons for the extension of the product development cycle and the impact on product market competitiveness. A slurry blade is one of the most common mechanical structures, which is widely used in wind power, ship, hydropower, and other fields. To identify the parameter defects of mechanical product design in the early stage of the design stage, this paper proposes the parameter design optimization identification model based on Stacking integrated learning and studies the parameter selection and results in the analysis of the slurry blade model. Space Claim software in Ansys software establishes three-dimensional slurry blade models with different scales. Combined with the NSGA II optimization algorithm, the multi-objective optimization design of the aerofoil structure is carried out. The CFD software is used to simulate and verify the slurry blade model after parameter design optimization. The results show that the optimization identification model for the design of slurry blade parameters based on the Stacking integrated learning algorithm can realize the influence of the unexpected change of design parameters on the design results. The prediction accuracy of cavitation proportion is high under different working conditions, and the absolute error is <0.02. The simulation of the optimized blade shows that the cavitation proportion e reaches a minimum of 0.005. The purpose of guiding the selection of design parameters, machining parameters, and assembly accuracy parameters is achieved, the structural defects of the slurry blade are reduced, and the working efficiency of the edge is improved.

Numerical Study of a Miniaturized, 1–3 Piezoelectric Composite Focused Ultrasound Transducer

This study aimed to develop an optimal methodology for the design of a miniaturized, 1–3 piezoelectric composite focused ultrasound transducer. Miniaturized focused ultrasound (FUS) devices, generally guided through catheters, have received considerable attention in the biomedical and ultrasound fields as they can overcome the technical restrictions of typical FUS transducers. However, miniaturized transducers cannot readily generate a high acoustic intensity because of their small aperture sizes and the vibration mode coupling. As such, 1–3 composite transducers, having a high electromechanical coupling and efficient vibration directivity, break through the current technical restrictions. However, the systematic methodology for designing miniaturized FUS transducers has not been thoroughly discussed so far. Therefore, in this study, we designed 1–3 piezoelectric composite transducers using analytical and numerical methods. Specifically, extensive parametric studies were performed through finite element analysis under the coupled field with piezoelectricity, structural vibration, and acoustic pressure. The simulation results confirmed that the optimal design of the 1–3 composite type transducer produces much higher (&gt;160%) acoustic pressure output at the focal point than the single-phase device. Furthermore, the array type of the interstitial transducer was predicted to produce an unprecedented acoustic intensity of approximately 188 W/cm2 under a short duty cycle (1%). This study will provide valuable technical methodology for the development of interstitial, 1–3 composite FUS transducers and the selection of optimal design parameters.

Statistical evaluation on hydrologic performance of bioretention design parameters under different rainfall conditions

Effectiveness of a bioretention cell (BC) in mitigating stormwater peak flow load to an urban drainage system is highly dependent on the design configuration and retrofitting scale. The selection of appropriate BC design parameters has always been critical to achieving its maximum benefits. The BC modeling in the stormwater management model (SWMM) relies on numerous design parameters (in total of 18) with wide selection ranges, making parameter selection challenging. This study investigated the effect of hydrologic dynamics of BC design parameters under different rainfall conditions (i.e., intensity, duration, time-to-peak) on surface infiltration, surface outflow, and storage. Firstly, the seven influential BC design parameters (i.e., conductivity, berm height, vegetation volume, suction head, porosity, wilting point, and soil thickness) were selected based on one-factor-at-a-time (OAT) method, and 1000 random samples of each parameter were generated across the factor space by following respective uniform distributions. The simulations were performed with a python wrapper of SWMM (PySWMM) that used random samples for one parameter while leaving the others constant each time. In general, the statistical results of each parameter represent a significant variation in the volume distribution under various design rainfall conditions. Comparatively, the parameters of conductivity, berm height, and vegetation volume are categorized as the most influential compared to other BC design parameters for surface infiltration, storage, and surface outflow, respectively.

Designing Bayesian Two-Sided Group Chain Sampling Plan for Gamma Prior Distribution

Acceptance sampling is used to decide either the whole lot will be accepted or rejected, based on inspection of randomly sampled items from the same lot. As an alternative to traditional sampling plans, it is possible to use Bayesian approaches using previous knowledge on process variation. This study presents a Bayesian two-sided group chain sampling plan (BTSGChSP) by using various combinations of design parameters. In BTSGChSP, inspection is based on preceding as well as succeeding lots. Poisson function is used to derive the probability of lot acceptance based on defective and non-defective products. Gamma distribution is considered as a suitable prior for Poisson distribution. Four quality regions are found, namely: (i) quality decision region (QDR), (ii) probabilistic quality region (PQR), (iii) limiting quality region (LQR) and (iv) indifference quality region (IQR). Producer’s risk and consumer’s risk are considered to estimate the quality regions, where acceptable quality level (AQL) is associated with producer’s risk and limiting quality level (LQL) is associated with consumer’s risk. Moreover, AQL and LQL are used in the selection of design parameters for BTSGChSP. The values based on all possible combinations of design parameters for BTSGChSP are presented and inflection points’ values are found. The finding exposes that BTSGChSP is a better substitute for the existing plan for industrial practitioners.

Selection of design parameters of the system for changing the supply of power supplies for hydraulic systems of aircraft

The article develops a mathematical model of the variable flow pump of the aircraft power supply, designed to simulate the operation of the power supply depending on the speed of the sustainer engine, oil temperature, pressure and supply (removable power). In addition, a control algorithm has been developed that provides the required quality of the transient process, which is achieved by installing additional hydraulic resistances between the servo piston cavity, the drain hydraulic line and the control spool, which change the flow characteristic of the pump and contribute to the fastest attenuation of the transient process and reduce its oscillation.

An approach to the selection of design parameters based on conflict with constraints

The Axiomatic Design (AD) supports decision-making based on the axioms of independence and information. In the engineering design activity, the designer must make early decisions that impact the success of the project. These decisions are of paramount importance in the design of one-off products. In these products, one must make decisions in the early design phases, with scarce data about the product that will undeniably affect the solution. Applying the information axiom requires data from the alternative solutions under consideration that for one-off products are most often non-existent in the conceptual phase of the design.Additionally, the design process is highly conditioned by existing constraints, which significantly influence the outcome. This work suggests selecting design parameters (DP) for one-off products from different sets of proposals that comply with the independence of functional requirements (FR). AD design follows a hierarchical decomposition process from a conceptual to a detailed design. The proposed method allows selecting the DPs among the set of alternatives by quantifying the degree of conflict each solution presents to the constraints. It shows the first step to define the DPs, at each level of decomposition of the AD process. It is the first step to establish a zig in AD or, otherwise, a way to find a solution in the conceptual phase. It applies to one-off products – any product with one chance to be right. The paper applies this method to the DP selection of a manipulation device.

An integrated approach for selecting design parameters in smart product-service system conceptual design

Nowadays, with the rapid development of cyber physical systems, IoT, and artificial intelligence, more and more attention has been paid to adapting the combination of smart, connected products and their generated services. Among these, smart product-service system (SPSS) with the unique features of smartness, connection, value co-creation, and data-driven has been widely concerned. Therefore, based on axiomatic design theory, the mapping from function domain to physical domain is a critical process in SPSS's conceptual design and the selecting of design parameters in physical domain has great impact on meeting multi-stakeholders’ benefits. Nevertheless, despite a few works on requirement conversion, it is not clear about the mapping mechanism under the target of value co-creation. Aiming to fill this gap, an integrated SPSS conceptual design method is proposed to solve the cross-domain mapping problem. It decomposes and reorganizes SPSS's function requirements with requirement development laws in TRIZ and divides the physical domain into product-related domain and service-related domain. Design parameters would be selected and evaluated by domain experts based on fuzzy comprehensive evaluation from different dimensions, which could represent the benefit of multi-stakeholders. Next, a binary integer programming (BIP) model with restrictions from different stakeholders would be constructed, which could be regarded as a multi-objective optimization problem. To solve the BIP model, the genetic algorithm is used and the optimal design parameters combination could be generated as the output of this process. Finally, a case study is carried out to demonstrate the feasibility and advantages of the integrated approach for cross-domain mapping in SPSS conceptual design.

Selected design parameters of a thermal management system for a lithium-ion phosphate battery

Selected design parameters of a thermal management system for a lithium-ion phosphate battery